scientificamerican--2020-10-08--Inequality before Birth Contributes to Health Inequality in Adults

The COVID-19 pandemic has disproportionately hurt members of minority communities in the U.S. As of late July , 73.7 Black @ @ @ @ @ had died of the coronavirus—compared with 32.4 of every 100,000 white people .
Structural racism @ @ @ @ @ disparity .
African-Americans are more likely to have jobs that require them to leave their @ @ @ @ @ public transport , for example , both of which increase the chances of getting infected @ @ @ @ @ likely to get grievously ill when the virus strikes .
As of early June , @ @ @ @ @ who tested positive for SARS-CoV-2 infection was more than four times higher for Black people @ @ @ @ @ .

Editor’s Note (12/21/21): This article is being showcased in a special collection about equity in health care that was made possible by the support of Takeda Pharmaceuticals. The article was published independently and without sponsorship.
The COVID-19 pandemic has disproportionately hurt members of minority communities in the U.S. As of April 2022, 339 Black people out of every 100,000 had died of the coronavirus, compared with 322 of every 100,000 white people. Structural racism accounts for much of this disparity. Black people are more likely to have jobs that require them to leave their homes and to commute by public transport, for example, both of which increase the chances of getting infected. They are also more likely to get grievously ill when the virus strikes. As of March 2022, the hospitalization rate for those who tested positive for SARS-CoV-2 infection was more than two times higher for Black people than for non-Hispanic white people.
One reason for this alarming ratio is that Black people have higher rates of diabetes, hypertension and asthma—ailments linked to worse outcomes after infection with the coronavirus. Decades of research show that these health conditions, usually diagnosed in adulthood, can reflect hardships experienced while in the womb. Children do not start on a level playing field at birth. Risk factors linked to maternal poverty—such as malnutrition, smoking, exposure to pollution, stress or lack of health care during pregnancy—can predispose babies to future disease. And mothers from minority communities were and are more likely to be subjected to these risks.
Today’s older Black Americans—those most endangered by COVID—are more likely than not to have been born into poverty. In 1959, 55 percent of Black people in the U.S. had incomes below the poverty level, compared with fewer than 10 percent of white people. Nowadays 20 percent of Black Americans live below the poverty line, whereas the poverty rate for white Americans remains roughly the same. Despite the reduction in income inequality between these groups, ongoing racism works through circuitous routes to worsen the odds for minority infants. For example, partly because of a history of redlining (practices through which financial and other institutions made it difficult for Black families to buy homes in predominantly white areas), even better-off Black people are more likely to live in polluted areas than are poorer white people—with a corresponding impact on fetal health. Worryingly, people disadvantaged in utero are more likely to have lower earnings and educational attainments, so that the effects of poverty and discrimination can span generations.
Researchers now have hard evidence that targeted programs can improve health and reduce inequality. Expansions of public health insurance offered to women, infants and children under Medicaid and the Children’s Health Insurance Program have had a tremendous effect, improving the health and well-being of a generation—with the largest impacts on Black children. And interventions after birth can often reverse much of the damage suffered prenatally. Along with other researchers, I have shown that nutrition programs for pregnant women, infants and children; home visits by nurses during pregnancy and after childbirth; high-quality child care; and income support can improve the outcomes for disadvantaged children. Such interventions came too late to help those born in the 1950s or earlier, but they have narrowed the health gaps between poor and rich children, as well as between white and Black children, in the subsequent decades.
Enormous disparities in health and vulnerability remain, however, and raise disturbing questions about how children born to poorer mothers during the current pandemic, with all its social and economic dislocations, will fare. Disturbingly, just before the pandemic hit, many of the most essential programs were being cut back. Between 2018 and 2020, more than a million children lost Medicaid coverage because of new work requirements and other regulations, and many became uninsured. Now that the COVID death toll has exposed stark inequalities in health status and their attendant risks, Americans must act urgently to reverse these setbacks and to strengthen public health systems and the social safety net, with special attention to the care of mothers, infants and children.
The Hunger Winter
Decades of careful observation and analysis have gone into uncovering the manifold ways in which the fetal environment affects the future health and prospects of a child, and much remains mysterious. It would be unethical to run experiments to measure the toll on a fetus of, say, malnutrition or pollution. But we can look for so-called natural experiments—the (sometimes horrific) events that cause variations in these factors in ways that mimic an actual experiment. The late epidemiologist David Barker argued in the 1980s that poor nutrition during pregnancy could “program” babies in the womb to develop future ailments such as obesity, heart disease and diabetes. Initial evidence for such ideas came from studies of the Dutch “Hunger Winter.” In October 1944 Nazi occupiers cut off food supplies to the Netherlands, and by April 1945 mass starvation had set in. Decades later military, medical and employment records showed that adult men whose mothers were exposed to the famine while pregnant with them were twice as likely to be obese as other men and were more likely to have schizophrenia, diabetes or heart disease.
Anyone born in the Netherlands during the famine is part of a cohort that can be followed over time through a variety of records. Nowadays many researchers, including me, look for natural experiments to delineate such cohorts and thereby tease out the long-term impacts of various harms experienced in utero. We also rely heavily on the most widely available measure of newborn health: birth weight. A baby may have “low” birth weight, defined as less than 2,500 grams (about 5.5 pounds), or “very low” birth weight of less than 1,500 grams (3.3 pounds). The lower the birth weight, the higher the risk of infant death. We have made enormous progress in saving premature babies, but low-birth-weight children are still at much higher risk for complications such as brain bleeds and respiratory problems that can lead to long-term disability.
In recent years computer analysis of large-scale electronic records has made it possible to connect infant health, as measured by birth weight, to long-term outcomes not just for cohorts but also for individuals. Studies of twins or siblings, who have similar genetic and social inheritance, show that those with lower birth weight are more likely to have asthma or attention deficit hyperactivity disorder (ADHD) when they get older. Several studies also show that lower-birth-weight twins or siblings have worse scores on standardized tests. As adults, they are more likely to have lower wages, to reside in lower-income areas or to be on disability-assistance programs. In combination, cohort and sibling studies demonstrate that low birth weight is predictive of several adverse health outcomes later in life, including increased probabilities of asthma, heart disease, diabetes, obesity and some mental health conditions.
Birth weight does not capture all aspects of a child’s health: a fetus gains most of its weight in the third trimester, for example, but many studies find that shocks in the first trimester are particularly harmful. I nonetheless use the measure in my studies because it is important and commonly available, having been recorded for tens of millions of babies for decades.
Significantly, low birth weight is much more common among infants born to poor and minority mothers. In 2016 13.5 percent of Black mothers had low-birth-weight babies, compared with 7.0 percent of non-Hispanic white mothers and 7.3 percent of Hispanic mothers. Among those with college educations, 9.6 percent of Black mothers had low-birth-weight babies, compared with 3.7 percent of non-Hispanic white mothers. These inequalities in health at birth reflect large differences in exposure to several factors that affect fetal health.
The Poverty Connection
As already noted, the quality of a mother’s nutrition substantially influences the health of her babies. In 1962 geneticist James V. Neel hypothesized that a so-called thrifty gene had programmed humankind’s hunter-gatherer ancestors to hold on to every calorie they could get and that in modern times, that tendency, combined with an abundance of high-calorie foods, led to obesity and diabetes. Studies on laboratory animals indicate, however, that the link between starvation and disease is not genetic in origin but epigenetic, altering how certain genes are “expressed” as proteins. Prolonged calorie deprivation in a pregnant mouse, for example, prompts changes in gene expression in her offspring that predispose them to diabetes. What is more, the effect may be transmitted through generations.
Outright starvation is now rare in developed countries, but poorer mothers in the U.S. often lack a diet rich in fruits and vegetables, which contain essential micronutrients. Deficiencies in folate intake during pregnancy are linked to neural tube defects in children, for example.
Credit: Amanda Montañez; Source: “Is It Who You Are or Where You Live? Residential Segregation and Racial Gaps in Childhood Asthma,” by Diane Alexander and Janet Currie, in Journal of Health Economics, Vol. 55; July 25, 2017
At present, one of the leading causes of low birth weight in the U.S. is smoking during pregnancy. In the 1950s pregnant women were told that smoking was safe for their babies. Roughly half of all new mothers in 1960 reported smoking while pregnant. Today, thanks to public education campaigns, indoor-smoking bans and higher cigarette taxes, only about 6 percent of pregnant women say that they smoke. And 54 percent of women who smoked in the three months before they got pregnant quit for at least the duration of their pregnancy.
Possibly because going to college places women in a milieu where smoking is strongly discouraged, mothers with higher education levels are less likely to smoke. Among mothers with less than a high school education, 11.2 percent smoke, compared with fewer than 1 percent of mothers with a bachelor’s degree.
Among the many harmful chemicals in cigarette smoke is carbon monoxide (CO), which restricts the amount of oxygen carried by the blood to the fetus. In addition, nicotine affects the development of blood vessels in the uterus and disrupts developing neurotransmitter systems, leading to poorer psychological outcomes. Maternal cigarette smoking during pregnancy has also been associated with epigenetic changes in the fetus, although how these alterations affect an individual in later years remains mysterious. Vaping, which has surged since 2010, delivers high doses of nicotine, and surveys show that it has been tried by almost 40 percent of high school seniors. This rise in popularity is extremely alarming because it could have long-term implications for fetal and infant health.
Yet another significant source of harm for fetuses is pollution. Pregnant women may be exposed to thousands of toxic chemicals in the air, water, soil and sundry products at home and at work. Complicating matters, each pollutant acts in a different way. Particulates in the atmosphere are thought to cause inflammation throughout the body, which has been linked to preterm labor and, consequently, to low birth weight. Lead, ingested through water or air, crosses the placenta to accumulate in the fetus and harm brain development. In 2005 Jessica Wolpaw Reyes of Amherst College showed that the phaseout of leaded gasoline in the U.S. led to a decrease of up to 4 percent in infant mortality and low birth weight.
A fetus may also receive less oxygen if its mother inhales CO from vehicle exhaust. In a 2009 study of mothers who lived near pollution monitors, my co-workers and I found that high levels of ambient CO were correlated with reduced birth weight. Worryingly, the effects of CO from air pollution are five times greater for smokers than for nonsmokers.
Reducing pollution can have immediate benefits for pregnant women and newborns. In a 2011 study of babies born in New Jersey and Pennsylvania, Reed Walker of the University of California, Berkeley, and I focused on mothers who lived near E-ZPass electronic toll plazas before and after they began operating. We compared them with mothers who lived a little farther from the toll plazas but along the same busy roads. Both groups of mothers were exposed to traffic, but before E-ZPass, the mothers near the toll plazas were exposed to more pollution because cars idled while waiting to pay the tolls. E-ZPass greatly reduced pollution right around the toll plazas by allowing cars to drive straight through. Startlingly, the introduction of E-ZPass reduced the incidence of low birth weight by more than 10 percent in the neighborhoods nearest the toll plazas.
In another study, my collaborators and I examined birth records for 11 million newborns in five states. We found that a shocking 45 percent of mothers lived within about a mile of a site that emitted toxic chemicals such as heavy metals or organic carcinogens—a number that rose to 61 percent among Black mothers. Focusing on babies born to mothers who lived within a mile of a plant, we compared birth weights when the facility was operating with birth weights when it was closed. For additional context, we also compared babies born within a mile of a plant with babies born in a one-to-two-mile band around the plants. Both groups of mothers were likely to be similarly affected by the economics of factory openings and closings, but mothers who lived closer were more likely to have been exposed to pollution during pregnancy. We found that an operating plant increased the probability of low birth weight by 3 percent among babies whose mothers lived less than a mile from the plant.
The racial divide in pollution exposure is profound, in part because of continuing segregation in housing that makes it difficult for Black families to move out of historically Black neighborhoods. Disadvantaged communities may also lack the political power to fend off harmful development, such as a chemical plant, in their vicinity. In the E-ZPass study, roughly half of the mothers who lived next to toll plazas were Hispanic or Black, compared with only about a tenth of mothers who lived more than six miles away from a toll plaza. And in a paper published in 2020, John Voorheis of the U.S. Census Bureau, Walker and I showed that across the entire U.S., neighborhoods with higher numbers of Black residents have systematically worse air quality than other neighborhoods. Black people are also twice as likely as others to live near a Superfund hazardous waste site. For these reasons, pollution-control measures such as the Clean Air Act have greatly benefited Black people.
Fight or Flight
Stress disproportionately impacts the poor—who have chronic worries about paying bills, for example—and also harms fetuses. A stressful situation triggers the release of hormones that orchestrate a range of physical changes associated with the fight-or-flight response. Some of these hormones, including cortisol, have been linked to preterm labor, which in turn leads to low birth weight. High circulating levels of cortisol in the mother during pregnancy may damage the fetus’s cortisol-regulation system, making it more vulnerable to stress. And stress can trigger behavioral responses in a mother such as increased smoking or drinking, which are also harmful to the fetus.
One revealing study indicates that fetal exposure to maternal stress can have greater negative long-term effects on mental health than stress directly experienced by a child. Petra Persson and Maya Rossin-Slater, both at Stanford University, looked at the impact of the death of a close relative. Death can bring many unwelcome changes to a family, such as reduced income, which may also influence child development. To account for such complications, the researchers used administrative data from Sweden to compare children whose mothers were affected by a death during the prenatal period with those whose mothers were affected by a death during the child’s early years. They found that children affected by a death prenatally were 23 percent more likely to use medication for ADHD at ages nine to 11 and 9 percent more likely to use antidepressants in adulthood than were children whose families experienced a death a few years after their birth.
Another pathbreaking study measured levels of cortisol, an indicator of stress, during pregnancy. By age seven, children whose mothers had higher cortisol levels during pregnancy had received up to one year less schooling than their own siblings, indicating that they had been delayed in starting school. Moreover, for any given level of cortisol in the mother’s blood, the negative effects were more pronounced for children born to less educated mothers. This finding suggests that although being stressed during pregnancy is damaging to the fetus, mothers with more education are better able to buffer the effects on their children—an important finding in view of the severe stress imposed by COVID on families today.
It is no surprise that disease can also harm a fetus. Douglas V. Almond of Columbia University looked at people born in the U.S. at the peak of the influenza epidemic of 1918 and found that they were 1.5 times more likely to be poor as adults than were those born just before them. In work I conducted with Almond and Mariesa Herrmann of Mathematica looking at mothers born between 1960 and 1990 in the U.S., we found that women who were born in areas where an infectious disease was raging were more likely to have diabetes when they gave birth to their own children decades later—and the effects were twice as large for Black people.
More recently, Hannes Schwandt of Northwestern University examined Danish data and found that maternal infection with ordinary seasonal influenza in the third trimester doubles the rate of premature birth and low birth weight, and infection in the second trimester leads to a 9 percent reduction in earnings and a 35 percent increase in welfare dependence once the child reaches adulthood.
Preventing Harm
Health at birth and beyond can nonetheless be improved through thoughtful interventions targeting pregnant women, babies and children and through reductions in pollution. The food safety net in the U.S. has already had tremendous success in preventing low birth weight in the babies of disadvantaged women. The rollout of the food stamp program (now called the Supplemental Nutrition Assistance Program, or SNAP) across the U.S. in the mid-1970s reduced the incidence of low birth weight by between 5 and 11 percent. In addition, children who benefited from the rollout grew up to be less likely to have metabolic syndrome—a cluster of conditions that include obesity and diabetes. Notably, women who had benefited as fetuses or young children were more likely to be economically self-sufficient.
The 1970s also saw the introduction of the Special Supplemental Nutrition Program for Women, Infants and Children, popularly known as WIC. Approximately half of eligible pregnant women in the U.S. receive nutritious food from WIC, along with nutrition counseling and improved access to medical care. Dozens of studies have shown that when women participate in WIC during pregnancy, their babies are less likely to have low birth weight. In work looking at mothers in South Carolina, Anna Chorniy of Northwestern, Lyudmyla Ardan (Sonchak) of Susquehanna University and I were able to show that children whose mothers received WIC during pregnancy were also less likely to have ADHD and other mental health conditions that are commonly diagnosed in early childhood.
Skyline of Flint, Mich., in 2016, after declaration of a federal emergency because of lead contamination in the water supply. Credit: Brett Carlsen Getty Images
In the late 1980s and early 1990s, state and federal governments worked together to greatly expand public health insurance for pregnant women under the Medicaid program. In work with Jonathan Gruber of the Massachusetts Institute of Technology, I showed that public health insurance lowered infant mortality and improved birth weight. Today the children whose mothers became eligible for health insurance coverage of their pregnancies in that period have higher levels of college attendance, employment and earnings than the children of mothers who did not. They also have lower rates of chronic conditions and are less likely to have been hospitalized. The estimated effects are strongest for Black people, who, having lower average incomes, benefited the most from the expansions. The fact that these babies are more likely to eventually get a college education also increases the life chances of their children. In the U.S., an additional year of college education for the mother reduces the incidence of low birth weight in her children by 10 percent.
Even so, too many children are still born with low birth weight, especially if their mothers are Black. Significantly, targeted interventions after birth can improve their outcomes. Programs such as the Nurse-Family Partnership provide home visits by nurses to low-income women who are pregnant for the first time, many of whom are young and unmarried. The nurse visits every month during the pregnancy and for the first two years of the child’s life to provide guidance about healthy behavior. The assistance reduces child abuse and adolescent crime and enhances children’s academic achievement.
Providing cash payments to poor families with young children also improves both maternal health and child outcomes, suggesting that COVID relief payments will have important protective effects. In the U.S., the largest preexisting program of this type is the Earned Income Tax Credit (EITC). Studies of beneficiaries of the EITC show that children in families that received increased amounts had higher test scores in school. With financial stress being somewhat relieved, the mental health of mothers in these families also improved. In addition, quality early-childhood education programs augment future health, education and earnings and reduce crime. Head Start, the federally funded preschool program that was rolled out beginning in the 1960s, has also had substantial positive effects on health and education outcomes, especially in places with less access to alternative child care centers.
A 2018 study, especially noteworthy in light of the tragic lead poisoning in Flint, Mich., shows that even some of the negative effects of lead can be reversed. In Charlotte, N.C., lead-poisoned children who received lead remediation, nutritional and medical assessments, WIC and special training for their caregivers saw reductions in problem behaviors and advanced school performance.
Looking Ahead
Investments in pregnant women and infants have been paying off, their success reflected in dramatically falling infant mortality rates in the U.S.—despite rising inequality in income and wealth. Alarmingly, however, many successful programs, such as the Clean Air Act, SNAP and Medicaid, are under attack. The Coronavirus Aid, Relief and Economic Security (CARES) Act passed in March 2020 provided some relief, at least with respect to Medicaid. CARES temporarily suspended disenrollment from the program, giving additional flexibility to state Medicaid programs in terms of time lines and eligibility procedures. Still, states may be hard-pressed to enroll the many who will become newly eligible for Medicaid because of job loss. Moreover, states that have not expanded the Medicaid program to cover otherwise ineligible low-income adults, as allowed by the Affordable Care Act, may see many more uninsured.
A National Academies of Sciences, Engineering and Medicine report published in 2019 laid out a road map for reducing child poverty by half within 10 years. One of the most stunning findings of the report is that it is feasible to meet that target by expanding programs that already exist. Following these directions would have a profound impact on health and health disparities. Targeted approaches, such as more thorough investigation of maternal deaths occurring up to one year after a birth, are also necessary. Even simple preventive measures such as giving pregnant women flu shots can have a tremendously positive effect on infant health and child development. Diagnosis and treatment of conditions such as preeclampsia (high blood pressure associated with pregnancy) are key to both protecting babies and lowering maternal mortality rates. It is important to help pregnant women quit smoking and to develop new approaches relevant to a new generation addicted to vaping. Also needed are stronger protections for women at risk of domestic violence, which leads directly to chronic stress, premature deliveries and low birth weight.
One salient open question is what effect the pandemic will have on the generation of children affected by it in utero and in early life. COVID itself may have negative effects on the developing fetus. The latest data suggest that although the overall risk is low, pregnant women are at increased risk of becoming critically ill (as they are with influenza or SARS). Affected babies, however, do not seem to be at risk of obvious birth defects (as they are with the Zika virus). Still, given the fact that COVID affects many body systems, it may prove to have subtler negative effects on the developing fetus. The pandemic is also an extremely stressful event compounded by the sharpest economic downturn since the Great Depression. The years 2020 and 2021 saw marked increases in domestic violence, alcohol consumption and drug overdoses, all of which are known to be harmful to the developing fetus. In consequence, the generation being born now is likely to be at increased risk going forward and will require intensive social investments to overcome its poorer start in life.
In a July 2020 sermon on the late civil rights leader John Robert Lewis, Reverend James Lawson recounted the significant gains for Americans of all colors that had resulted from that movement. He went on to ask that America’s political leaders “work unfalteringly on behalf of every boy and every girl, so that every baby born on these shores will have access to the tree of life ... let all the people of the U.S.A. determine that we will not be quiet as long as any child dies in the first year of life in the United States. We will not be quiet as long as the largest poverty group in our nation are women and children.” As we rebuild our shattered safety nets and public health systems in the aftermath of COVID, we need to seize the moment and use the knowledge we have gained about how to protect mothers and babies—to give every child the opportunity to flourish.


scientificamerican--2020-10-08--Yes, Science Is Political

Yes, Science Is Political

If you ’ re in STEM , you ’ ve likely heard this refrain before ; its sentiment might even resonate with you .
It may not surprise you that only 43.6 percent of STEM students voted in the last presidential election compared to 49.2 and 53.2 percent of students in the humanities and social sciences , respectively .
Science , however , has always been political ; the events of 2020 have only made the relationship between science and society more explicit .
We are in the midst of a pandemic and a climate crisis , both solvable by @ @ @ @ @ @ @ ignores scientists , the consequences can be fatal , disproportionately so for Black , brown and Indigenous communities .
Americans are suffering from wildfire-induced poor air quality .
More than 200,000 Americans have died from COVID-19 .
Yet , as our nation grapples with the pandemic , our current administration believes that “ science shouldn ’ t stand in the way ” of business as usual .
We can not accept this .
Now is the time for science , not silence .
In November , we scientists must vote for an administration @ @ @ @ @ @ @ in the formation of policy .
As scientists , we ’ re trained to think of the broader impacts of our research ; as citizens , we should make those thoughts concrete with our votes .
We have been trained think critically , analyze large amounts of data and come up with potential solutions to the problems we discover .
We can use these same skills to analyze policy , and we must , because doing so promotes an informed citizenry .
Various examples of scientists who did just this exist in our @ @ @ @ @ @ @ antiwar activist .
Andrei Sakharov fought against nuclear proliferation .
Women , in particular , have long been leaders in the environmental movement ; Rachel Carson wrote Silent Spring , sparking the contemporary environmental movement in the United States .
Wangari Maathai worked tirelessly throughout her life in many humanitarian efforts , including founding the Green Belt Movement .
These scientists made a societal impact by bringing their knowledge and expertise outside of the lab .
And today , scientist-activists including Dior Vargas , Ayana Elizabeth Johnson and Geoffrey Supran have continued this @ @ @ @ @ @ @ policies .
The classroom can be a starting point to encourage STEM students and scientists to become more civically engaged .
Just as we discuss problem sets , we should discuss how scientific advancements affect society , such as the potential benefits and dangers of unregulated facial recognition software and using CRISPR gene editing technology for therapeutic purposes .
Lessons should be taught on how science can be grounded in justice , such as in agroecology which is used for both sustainable farming and to promote a more just food system .
Likewise @ @ @ @ @ @ @ in politics that influence scientific data production and usage .
The current administration has censored climate scientists .
Until recently , scientists could not use federal funding to study gun violence , which is widely recognized as a public health crisis .
And of course , policies have real impact on our lives : immigration bans jeopardize the collaborative nature of scientific research and instead foster fear and uncertainty in researchers .
If you can vote , use your voice to support candidates and policies that prioritize using science for our common good @ @ @ @ @ @ @ universities , educators and students can use to increase STEM voter turnout this fall and beyond .
• None Make election days a university holiday so that all students , faculty , and staff have the opportunity to vote in person .
• None Use classrooms and auditorium spaces for polling , which will increase the accessibility of voting to students .
• None Include information about voter registration on your syllabus .
• None Remind students of voter registration deadlines .
Whether you have five minutes or a full class period , @ @ @ @ @ @ @ resources on how to bring democracy into the classroom • None Structure the course schedule with election days in mind : don ’ t plan exams , project due dates or mandatory participation activities for election week , to allow students ample time to vote in potentially long lines and not sacrifice important study time .
• None Incorporate discussions tying science to society .
March for Science NYC curated a panel series connecting science to voter issues .
• None Discuss the work that scientists have done as activists in your field @ @ @ @ @ @ @ co-workers : register to vote and make a voting plan together .
Organize your friends , classmates and STEM co-workers : register to vote and make a voting plan together .
• None Join or start an organization that focuses on science community building .
Examples include 500 Women Scientists Black in the Ivory and 500 Queer Scientists • None Attend or host a science and society lecture and discussion event to highlight how science can be used in policy .
• None Volunteer in your community with local citizen science groups , @ @ @ @ @ @ @ .
• None Whatever cause you are already passionate about—animal rights , the environment , world hunger , patient advocacy—learn how science relates and how policies can use this science to create effective solutions .
In short , as Rosalind Franklin , whom many think deserved to share the Nobel Prize for her role in elucidating the structure of DNA , said , “ Science and everyday life can not and should not be separated.
” For us scientists and citizens , we must advocate for science .
Our world is facing a @ @ @ @ @ @ @ , and is reckoning with centuries of unjust systems .
We need to organize and vote like it .

“Science isn’t political.”
If you’re in STEM, you’ve likely heard this refrain before; its sentiment might even resonate with you. It may not surprise you that only 43.6 percent of STEM students voted in the last presidential election , compared to 49.2 and 53.2 percent of students in the humanities and social sciences, respectively.
Science, however, has always been political; the events of 2020 have only made the relationship between science and society more explicit. We are in the midst of a pandemic and a climate crisis, both solvable by centering scientific expertise. When our government ignores scientists, the consequences can be fatal, disproportionately so for Black, brown and Indigenous communities. Americans are suffering from wildfire-induced poor air quality. More than 200,000 Americans have died from COVID-19. Yet, as our nation grapples with the pandemic, our current administration believes that “science shouldn’t stand in the way” of business as usual.
We cannot accept this. Now is the time for science, not silence. In November, we scientists must vote for an administration that allows science to lead the way in the formation of policy.
As scientists, we’re trained to think of the broader impacts of our research; as citizens, we should make those thoughts concrete with our votes. We have been trained think critically, analyze large amounts of data and come up with potential solutions to the problems we discover. We can use these same skills to analyze policy, and we must, because doing so promotes an informed citizenry. Various examples of scientists who did just this exist in our history. Albert Einstein was an outspoken antiwar activist. Andrei Sakharov fought against nuclear proliferation.
Women, in particular, have long been leaders in the environmental movement; Rachel Carson wrote Silent Spring, sparking the contemporary environmental movement in the United States. Wangari Maathai worked tirelessly throughout her life in many humanitarian efforts, including founding the Green Belt Movement. These scientists made a societal impact by bringing their knowledge and expertise outside of the lab. And today, scientist-activists including Dior Vargas, Ayana Elizabeth Johnson and Geoffrey Supran have continued this legacy, advocating for science and science-based policies.
The classroom can be a starting point to encourage STEM students and scientists to become more civically engaged. Just as we discuss problem sets, we should discuss how scientific advancements affect society, such as the potential benefits and dangers of unregulated facial recognition software and using CRISPR gene editing technology for therapeutic purposes. Lessons should be taught on how science can be grounded in justice, such as in agroecology , which is used for both sustainable farming and to promote a more just food system. Likewise, science classes should highlight current events in politics that influence scientific data production and usage. The current administration has censored climate scientists. Until recently, scientists could not use federal funding to study gun violence, which is widely recognized as a public health crisis. And of course, policies have real impact on our lives: immigration bans jeopardize the collaborative nature of scientific research and instead foster fear and uncertainty in researchers. If you can vote, use your voice to support candidates and policies that prioritize using science for our common good.
Below we have compiled suggestions that universities, educators and students can use to increase STEM voter turnout this fall and beyond.
For university administrators:
Make election days a university holiday so that all students, faculty, and staff have the opportunity to vote in person.
Use classrooms and auditorium spaces for polling, which will increase the accessibility of voting to students.
For educators:
Include information about voter registration on your syllabus.
Remind students of voter registration deadlines. Whether you have five minutes or a full class period, the Union of Concerned Scientists has shared resources on how to bring democracy into the classroom
Structure the course schedule with election days in mind: don’t plan exams, project due dates or mandatory participation activities for election week, to allow students ample time to vote in potentially long lines and not sacrifice important study time.
Incorporate discussions tying science to society. March for Science NYC curated a panel series connecting science to voter issues.
Discuss the work that scientists have done as activists in your field.
For students:
In short, as Rosalind Franklin, whom many think deserved to share the Nobel Prize for her role in elucidating the structure of DNA, said, “Science and everyday life cannot and should not be separated.” For us scientists and citizens, we must advocate for science. Our world is facing a life-threatening climate crisis and a neglected pandemic, and is reckoning with centuries of unjust systems. We need to organize and vote like it.


scientificamerican--2020-10-08--Nobelist Talks CRISPR Uses

Nobelist Talks CRISPR Uses

Steve Mirsky : On October 7th , Jennifer Doudna and Emmanuelle Charpentier shared the 2020 Nobel Prize in Chemistry for the development of the gene editing tool called CRISPR .
Last April , I spoke with Doudna at an event in Washington , DC : SM : A few months ago , I was at a talk about wine .
And CRISPR came up .
And it was it was an appropriate thing to bring up .
What is it like to be in this field right now where everyone is talking about the work that you do and its @ @ @ @ @ @ @ I have to say it 's very exciting .
And as a scientist , it ’ s wonderful to see all the creative work that 's going on with gene editing .
It 's just a fascinating opportunity to see the innovation that people come up with when they have a tool that 's so broadly useful across biology .
SM : You do a million interviews and you make a lot of public talks .
What do people not talk to you about that you would love to talk about regarding CRISPR @ @ @ @ @ @ @ a lot of the discussion around CRISPR right now focuses on biomedical applications , which clearly are very exciting .
I think , something that I do n't hear as much , although I 'm happy to hear that you had this conversation at a wine event .
It are the opportunities in agriculture , I think they 're going to be huge .
And I 'm really , really excited about the opportunities to use gene editing to create plants that will be drought tolerant , pest resistant , maybe more nutritious @ @ @ @ @ @ @ in environments where in the past they 've been really challenging to grow .
SM : Yeah , the range of applications is just seemingly endless .
I think in the wine talk , we were discussing the threats to viniculture from global warming , right .
And one of the possible applications there is to get the more heat- tolerant organisms to chip in , help the wine grapes .
You talk about the ethical considerations a lot .
Anything you 'd like to discuss ?
JD : I think the ethical @ @ @ @ @ @ @ very excited and concerned appropriately , I think , on occasion about opportunities to use gene editing , in systems where , you know , we really need to be thoughtful about the responsible use , where there are great opportunities , but also big , big challenges .
And of course , a very obvious one is in the human germline embryo editing , but also , frankly , also in microbes and other organisms that could be released into the environment , using gene editing to spread genetic traits in a @ @ @ @ @ @ @ 's another area where there 's a lot of discussion about how careful we need to be how do we regulate this technology appropriately ?
How do we encourage science to advance but do it in a way that 's responsible ?

Full Transcript
STEVE MIRSKY: On October 7, Jennifer Doudna and Emmanuelle Charpentier shared the 2020 Nobel Prize in Chemistry for the development of the gene-editing tool called CRISPR. Last April I spoke with Doudna at an event in Washington, D.C.
MIRSKY: A few months ago, I was at a talk about wine, and CRISPR came up. And it was it was an appropriate thing to bring up. What is it like to be in this field right now, where everyone is talking about the work that you do and its implications?
DOUDNA: Well, I have to say it’s very exciting. And as a scientist, it’s wonderful to see all the creative work that’s going on with gene editing. It’s just a fascinating opportunity to see the innovation that people come up with when they have a tool that’s so broadly useful across biology.
MIRSKY: You do a million interviews, and you make a lot of public talks. What do people not talk to you about that you would love to talk about regarding CRISPR?
DOUDNA: Well, I think a lot of the discussion around CRISPR right now focuses on biomedical applications, which clearly are very exciting. I think something that I don’t hear as much—although I’m happy to hear that you had this conversation at a wine event—are the opportunities in agriculture. I think they’re going to be huge. And I’m really, really excited about the opportunities to use gene editing to create plants that will be drought-tolerant, pest-resistant, maybe more nutritious—give farmers opportunities to grow plants in environments where, in the past, they’ve been really challenging to grow.
MIRSKY: Yeah, the range of applications is just seemingly endless. I think in the wine talk, we were discussing the threats to viniculture from global warming, right. And one of the possible applications there is to get the more heat- tolerant organisms to chip in, help the wine grapes. You talk about the ethical considerations a lot. Anything you’d like to discuss?
DOUDNA: I think the ethical considerations are incredibly important. People get very excited and concerned, appropriately, I think, on occasion about opportunities to use gene editing in systems where, you know, we really need to be thoughtful about the responsible use—where there are great opportunities but also big, big challenges. And of course, a very obvious one is in the human-germ-line-embryo editing but also, frankly, also in microbes and other organisms that could be released into the environment—using gene editing to spread genetic traits in a mode called gene drives. So that’s another area where there’s a lot of discussion about how careful we need to be. How do we regulate this technology appropriately? How do we encourage science to advance but do it in a way that’s responsible?
—Steve Mirsky
[The above text is a transcript of this podcast.]


scientificamerican--2020-10-08--Would a Green New Deal Add or Kill Jobs?

Editor ’ s Note ( 10/8/20 ) : At the October 7 vice presidential debate , Kamala Harris and Mike Pence tussled over the Green New Deal .
Several proposals have fallen under that banner .
How many jobs would one of them create ?
What kinds of jobs ?
Scientific American has detailed data on these questions .
Political candidates in the U.S. have been announcing plans to address climate change at a record pace .
With the mounting recognition of local , national and global threats , they want to show they are ready to act .
At @ @ @ @ @ @ @ releasing various forms of carbon tax legislation .
These initiatives are rekindling debate about how much of a price to put on carbon and what effects the options would have on the environment and the economy .
Increasingly , the action plans and tax proposals cite estimates of their employment impacts .
Among Democratic presidential primary candidates , for example , Senator Elizabeth Warren of Massachusetts claims that her plan would create 1.2 million jobs in green manufacturing , while former vice president Joe Biden and Senator Bernie Sanders of Vermont say their @ @ @ @ @ @ @ range .
At the other extreme , President Donald Trump has claimed that nationwide climate-change policies would be “ totally disastrous , job-killing.
” Some pundits say we can not save the planet without stalling economic growth .
Yet there is mounting evidence that both environmental and economic goals can be met .
At the center of this argument are several proposals falling under the banner of a green new deal , as well as the Energy Innovation and Carbon Dividend Act ( EICDA ) of 2019 .
Our independent review of a @ @ @ @ @ @ @ by the U.S. Green Party suggests it is possible to rapidly lower CO emissions while also expanding employment over the next three decades by an additional 35 million job years ( one job for one year ) .
Yet a more moderate tax on carbon could be economically more attractive .
It has become nearly axiomatic that efficient climate policies must put a tax on carbon emissions .
In the energy sector , a huge source of human CO emissions in the U.S. , levying taxes on the carbon content of fuels would @ @ @ @ @ @ @ more energy-efficient practices .
Emitters could choose their preferred carbon-reduction approach , and policy makers could adjust the tax as social damages from climate change evolve .
Many policy analysts argue that taxing carbon emissions from fossil fuels will foster economic growth and employment opportunities by boosting sales in labor-intensive clean-technology work and by promoting innovation .
This logic is at the heart of the GND as proposed by the Green Party .
It prescribes a transition to 100 percent clean energy by 2030—achieved in part by taxing CO emissions starting at $ @ @ @ @ @ @ @ increases and additional policies to ensure a socially just change .
Meanwhile the EICDA now in the House of Representatives starts with a $ 15 tax per metric ton of CO , which grows by $ 10 or $ 15 a year , depending on future levels of carbon emissions .
Critics have dismissed the GND as a green dream , arguing that the carbon tax would impose costs on society and cause job losses , particularly in fossil-based energy sectors .
Others assert that the timing is just too accelerated .
For @ @ @ @ @ @ @ in February , former Obama administration secretary of energy Ernest Moniz said , “ I 'm afraid I just can not see how we could possibly go to zero carbon in the 10-year timeframe .
It ’ s just impractical .
And if we start putting out impractical targets , we may lose a lot of key constituencies who we need to bring along to have a real low-carbon solution.
” The architects of the Green Party ’ s GND maintain that the initiative would not only avoid a climate catastrophe but that @ @ @ @ @ @ @ , ensure that the plan would pay for itself .
Analyses of carbon-tax impacts on U.S. employment are sparse because of the limited history of existing tax schemes .
Yet we can assess job impacts by using what is known as a computable general-equilibrium energy-economy model—in particular , the National Energy Modeling System ( NEMS ) , which was created by the U.S. Energy Information Administration ( EIA ) .
For more than a decade , the Georgia Institute of Technology has used its version of that model , known at GT-NEMS , @ @ @ @ @ @ @ climate policies .
The GND that we modeled starts in 2020 with a tax of $ 60 levied on each metric ton of CO emitted by the U.S. energy system .
The tax is set to increase annually at the rate of inflation , plus 5 percent .
We also examined a carbon tax starting at $ 25 and growing at the same rate , allowing a more moderate price to be compared with a higher tax .
By 2030 , the $ 25 tax would be $ 41 per metric ton of @ @ @ @ @ @ @ tax would be $ 98 .
By 2050 , the two taxes would rise to $ 108 and $ 259 , respectively .
In both scenarios , the tax revenues were returned to households by lowering federal personal income taxes , adjusted as necessary to avoid affecting the national deficit .
Recycling tax revenues to households as so-called carbon dividends is a feature of many recent carbon tax proposals , including the GND .
To identify the tax impacts , we compared the two scenarios with EIA ’ s “ reference case ” @ @ @ @ @ @ @ U.S. policies that were in place in 2018 and the introduction of those slated to be enacted after 2018 .
The reference case includes residential and commercial federal-efficiency standards and future increases to fuel economy and emissions standards for light-duty vehicles through 2025 , but it does not incorporate an economy-wide carbon tax in the U.S .
In the absence of a carbon tax , GT-NEMS forecasts that CO emissions from the U.S. energy system would be higher in 2050 than they are today .
In the short run , the declining use @ @ @ @ @ @ @ the uptick of natural gas , wind and solar power , and improvements in the energy efficiency of homes and light-duty vehicles are expected to cause the country ’ s overall CO emissions to decrease .
But by 2030 , this decline would taper off because of the growing energy requirements of businesses and manufacturers as the economy continues to expand—in the absence of any new incentives to decarbonize .
These scenarios reinforce the importance of strengthening environmental policies .
Otherwise , the U.S. will not embrace cleaner resources or curb its energy @ @ @ @ @ @ @ a growing economy .
In contrast , implementation of a $ 60 carbon tax would cause U.S. CO emissions to decline , relative to the reference case , by 28 percent in 2030 and by 37 percent in 2050 .
Across the U.S. economy , carbon taxes would transform the electricity system the most .
The reference case forecasts that carbon emissions from generating electricity would decline modestly through mid-century , with coal burned to generate power decreasing slightly to 656 million metric tons in 2050 .
A $ 60 carbon tax would @ @ @ @ @ @ @ almost entirely by 2030 : as a result , the power sector would experience a 72 percent reduction in CO , compared with the reference case , in 2030 and an 87 percent reduction in 2050 .
Even a more modest $ 25 carbon tax would trigger abundant low-cost clean electricity investments .
With a $ 25 tax , only 119 million metric tons of coal is forecast to be burned in 2030 , and it is cut to 62 million metric tons in 2050 .
On the other hand , transportation and @ @ @ @ @ @ @ be transformed the least by a carbon tax .
They are also the ones that depend the most on petroleum fuels .
Because of the relatively flat trajectory of natural gas prices in the reference case , natural gas used in the electricity sector is expected to increase year after year over the next three decades .
Introducing carbon taxes alters that forecast .
With a $ 25 tax , natural gas would peak nationwide in 2031 .
With a $ 60 tax , it would peak 10 years earlier , in 2021 @ @ @ @ @ @ @ in the reference case .
But with carbon taxes , their market shares would surge quickly .
Under both carbon tax levels , nuclear power would experiences= a renaissance , beginning in about 2035 and continuing through 2050 , when it would eclipse natural gas as a source of electricity .
These transformations would not occur uniformly across the U.S. Several factors would vary geographically and shape the costs and benefits of transitioning to cleaner fuels : the amount of fossil fuels and renewable resources ; access to pipelines , ports and other @ @ @ @ @ @ @ , including nuclear engineers ; and state and local regulations , incentives and financial markets .
As a result , some regions would reduce the carbon intensity of their energy systems faster than others .
We estimate that the more conservative $ 25 carbon tax would boost U.S. employment by 1.4 million jobs each year between 2020 and 2030 , which is nearly a 1 percent increase above the reference–case forecast of 160 million jobs in 2030 .
As the economy expands and the tax increases , job growth from the GND would @ @ @ @ @ @ @ 3.4 million new jobs each year between 2040 and 2050—a nearly 2 percent increase above the 182 million jobs forecast for the U.S. in 2050 .
Overall , it is estimated that 72 million job years would be created over the three decades with a $ 25 carbon tax .
( Note that if one job continues after one year for another 12 months , it represents two job years . )
With the more aggressive $ 60 carbon tax , U.S. employment would still exceed the reference-case forecast , but the increase @ @ @ @ @ @ @ $ 25 tax .
The higher tax causes much larger supply-side job losses , but they are still smaller than the gains in energy-efficiency jobs motivated by higher energy prices .
Overall , 35 million job years would be created between 2020 and 2050 , with net job increases in almost all regions .
According to the latest data , in 2018 about 9.2 million Americans ( 5.7 percent of the U.S. workforce of roughly 162 million at the time ) were employed in an energy industry .
Nearly half of these jobs @ @ @ @ @ @ @ the traditional supply-oriented categories : fuels , including petroleum , natural gas , coal and woody biomass ( 1.1 million ) ; electric power generation ( 900,000 ) ; and transmission , distribution and storage ( 2.3 million ) .
The motor-vehicle-related industries employed 2.5 million , and energy efficiency employed 2.4 million .
The GND would cause traditional supply-oriented jobs to decrease , but energy-efficiency jobs would more than compensate for the losses .
New jobs from energy-efficiency investments would be significant , totaling 1.8 million in 2030 and 4.2 million in @ @ @ @ @ @ @ of jobs in construction , which account for more than half of the energy-efficiency workforce in 2018 .
Other large gains would be associated with heating , ventilation , air-conditioning and refrigeration systems—the largest share of energy-efficiency investments in the residential and commercial sectors .
In industry , the greatest investments estimated would be in energy and environmental management and smart controls , followed by industrial-machinery manufacturing such as that of high-efficiency motors and variable-speed drives .
The result would be job growth across all nine Census divisions of the U.S. , in @ @ @ @ @ @ @ carbon tax .
The $ 60 tax would boost job growth in the U.S. overall and across a majority of its nine Census divisions and three decades .
Of the Census divisions , the Pacific and West North Central regions would be the only parts of the nation to experience job losses during both the 2020s and 2030s .
The New England region is also projected to lose jobs during the first decade as it adjusts to the requirements of the $ 60 carbon tax .
In contrast , West South Central and @ @ @ @ @ @ @ increase in energy-efficiency employment in both tax scenarios—and therefore would experience the largest job growth .
How large would the household dividends generated by taxes be ?
Imposing a $ 25 tax on each metric ton of CO produced in the electricity sector alone would result in national revenue of $ 35 billion in 2020 .
A $ 60 tax would boost it to $ 68 billion .
In aggregate , the resulting household income tax rebates , or “ dividends , ” would be greater than the increase in household utility bills @ @ @ @ @ @ @ and bills would be regionally diverse .
Dividends could be allocated uniformly across regions , but doing so would disadvantage regions with significant increases in energy prices .
Distributing dividends across households regardless of income , on the other hand , is a progressive feature of these proposed carbon-tax initiatives .
High-income households purchase more carbon-intensive goods and services than other income groups .
Therefore , low- and middle-income households would generally gain more in dividends than they would pay in increased prices from the introduction of carbon taxes .
The GND offers @ @ @ @ @ @ @ could advance from traditional fossil-fuel dependence to a future powered largely by low-carbon alternatives .
Our analysis indicates that a cleaner-energy approach motivated by carbon taxes would promote innovation , open up new markets and produce an economy with more jobs—a greener economy worth investing in .
Today clean-energy technologies in the U.S. struggle to compete because fossil energy is so “ inexpensive.
” Low prices make it difficult for such alternatives to flourish .
Our analysis shows that raising energy prices would empower the transition to efficiency , renewables and other low-carbon @ @ @ @ @ @ @ of either $ 25 or $ 60 would cut carbon emissions significantly , but the higher tax would produce quicker and deeper reductions .
On the other hand , while both tax levels would grow jobs , the $ 25 tax would provide more employment growth than the $ 60 one .
Thus , as with most policies , the optimum is a trade-off between competing priorities .
By using the clean technologies that carbon taxes would promote , Americans would not have to travel less , freeze in the winter , take @ @ @ @ @ @ @ their manufacturing plants to reduce the U.S. ’ s carbon emissions .
Our independent analysis , along with a growing body of research , suggests that a low-carbon economy is likely to be a stronger and more secure economy that also provides climate solutions .
Editor ’ s Note ( 12/19/19 ) : This story was updated to include a graphic showing “ Job Impacts by Sector .
”

Editor’s Note (10/8/20): At the October 7 vice presidential debate, Kamala Harris and Mike Pence tussled over the Green New Deal. Several proposals have fallen under that banner. How many jobs would one of them create? What kinds of jobs? Scientific American has detailed data on these questions.
Political candidates in the U.S. have been announcing plans to address climate change at a record pace. With the mounting recognition of local, national and global threats, they want to show they are ready to act. At the same time, elected officials are releasing various forms of carbon tax legislation. These initiatives are rekindling debate about how much of a price to put on carbon and what effects the options would have on the environment and the economy.
Increasingly, the action plans and tax proposals cite estimates of their employment impacts. Among Democratic presidential primary candidates, for example, Senator Elizabeth Warren of Massachusetts claims that her plan would create 1.2 million jobs in green manufacturing, while former vice president Joe Biden and Senator Bernie Sanders of Vermont say their proposals would provide jobs in the 10-million-to-20-million range. At the other extreme, President Donald Trump has claimed that nationwide climate-change policies would be “totally disastrous, job-killing.”
Some pundits say we cannot save the planet without stalling economic growth. Yet there is mounting evidence that both environmental and economic goals can be met. At the center of this argument are several proposals falling under the banner of a green new deal, as well as the Energy Innovation and Carbon Dividend Act (EICDA) of 2019. Our independent review of a Green New Deal (GND) proposed by the U.S. Green Party suggests it is possible to rapidly lower CO 2 emissions while also expanding employment over the next three decades by an additional 35 million job years (one job for one year). Yet a more moderate tax on carbon could be economically more attractive.
A False Choice between Climate and Jobs
It has become nearly axiomatic that efficient climate policies must put a tax on carbon emissions. In the energy sector, a huge source of human CO 2 emissions in the U.S., levying taxes on the carbon content of fuels would move investments to cleaner energy sources and more energy-efficient practices. Emitters could choose their preferred carbon-reduction approach, and policy makers could adjust the tax as social damages from climate change evolve.
Many policy analysts argue that taxing carbon emissions from fossil fuels will foster economic growth and employment opportunities by boosting sales in labor-intensive clean-technology work and by promoting innovation. This logic is at the heart of the GND as proposed by the Green Party. It prescribes a transition to 100 percent clean energy by 2030—achieved in part by taxing CO 2 emissions starting at $60 per metric ton, with annual increases and additional policies to ensure a socially just change. Meanwhile the EICDA now in the House of Representatives starts with a $15 tax per metric ton of CO 2 ,which grows by $10 or $15 a year, depending on future levels of carbon emissions.
Critics have dismissed the GND as a green dream, arguing that the carbon tax would impose costs on society and cause job losses, particularly in fossil-based energy sectors. Others assert that the timing is just too accelerated. For example, in an interview for NPR in February, former Obama administration secretary of energy Ernest Moniz said, “I'm afraid I just cannot see how we could possibly go to zero carbon in the 10-year timeframe. It’s just impractical. And if we start putting out impractical targets, we may lose a lot of key constituencies who we need to bring along to have a real low-carbon solution.” The architects of the Green Party’s GND maintain that the initiative would not only avoid a climate catastrophe but that its health savings would, by themselves, ensure that the plan would pay for itself.
Analyses of carbon-tax impacts on U.S. employment are sparse because of the limited history of existing tax schemes. Yet we can assess job impacts by using what is known as a computable general-equilibrium energy-economy model—in particular, the National Energy Modeling System (NEMS), which was created by the U.S. Energy Information Administration (EIA). For more than a decade, the Georgia Institute of Technology has used its version of that model, known at GT-NEMS, to forecast the impacts of energy and climate policies.
The GND that we modeled starts in 2020 with a tax of $60 levied on each metric ton of CO 2 emitted by the U.S. energy system. The tax is set to increase annually at the rate of inflation, plus 5 percent. We also examined a carbon tax starting at $25 and growing at the same rate, allowing a more moderate price to be compared with a higher tax. By 2030, the $25 tax would be $41 per metric ton of CO 2 emitted, and the $60 tax would be $98. By 2050, the two taxes would rise to $108 and $259, respectively.
In both scenarios, the tax revenues were returned to households by lowering federal personal income taxes, adjusted as necessary to avoid affecting the national deficit. Recycling tax revenues to households as so-called carbon dividends is a feature of many recent carbon tax proposals, including the GND. To identify the tax impacts, we compared the two scenarios with EIA’s “reference case” forecast, which assumes a continuation of U.S. policies that were in place in 2018 and the introduction of those slated to be enacted after 2018. The reference case includes residential and commercial federal-efficiency standards and future increases to fuel economy and emissions standards for light-duty vehicles through 2025, but it does not incorporate an economy-wide carbon tax in the U.S.
Carbon Taxes Cut CO 2 Emissions
In the absence of a carbon tax, GT-NEMS forecasts that CO 2 emissions from the U.S. energy system would be higher in 2050 than they are today. In the short run, the declining use of coal in the electricity sector, the uptick of natural gas, wind and solar power, and improvements in the energy efficiency of homes and light-duty vehicles are expected to cause the country’s overall CO 2 emissions to decrease. But by 2030, this decline would taper off because of the growing energy requirements of businesses and manufacturers as the economy continues to expand—in the absence of any new incentives to decarbonize. These scenarios reinforce the importance of strengthening environmental policies. Otherwise, the U.S. will not embrace cleaner resources or curb its energy appetite enough to offset the demands of a growing economy.
Credit: Amanda Montañez; Source: Marilyn A. Brown and Majid Ahmadi
In contrast, implementation of a $60 carbon tax would cause U.S. CO 2 emissions to decline, relative to the reference case, by 28 percent in 2030 and by 37 percent in 2050.
Across the U.S. economy, carbon taxes would transform the electricity system the most. The reference case forecasts that carbon emissions from generating electricity would decline modestly through mid-century, with coal burned to generate power decreasing slightly to 656 million metric tons in 2050. A $60 carbon tax would squeeze coal out of the power sector almost entirely by 2030: as a result, the power sector would experience a 72 percent reduction in CO 2 , compared with the reference case, in 2030 and an 87 percent reduction in 2050. Even a more modest $25 carbon tax would trigger abundant low-cost clean electricity investments. With a $25 tax, only 119 million metric tons of coal is forecast to be burned in 2030, and it is cut to 62 million metric tons in 2050.
On the other hand, transportation and industry are the economic sectors that would be transformed the least by a carbon tax. They are also the ones that depend the most on petroleum fuels.
Because of the relatively flat trajectory of natural gas prices in the reference case, natural gas used in the electricity sector is expected to increase year after year over the next three decades. Introducing carbon taxes alters that forecast. With a $25 tax, natural gas would peak nationwide in 2031. With a $60 tax, it would peak 10 years earlier, in 2021.
Credit: Amanda Montañez; Source: Marilyn A. Brown and Majid Ahmadi
Solar and wind power would grow in the reference case. But with carbon taxes, their market shares would surge quickly. Under both carbon tax levels, nuclear power would experiences= a renaissance, beginning in about 2035 and continuing through 2050, when it would eclipse natural gas as a source of electricity.
These transformations would not occur uniformly across the U.S. Several factors would vary geographically and shape the costs and benefits of transitioning to cleaner fuels: the amount of fossil fuels and renewable resources; access to pipelines, ports and other supply infrastructures; availability of specialized workforces, including nuclear engineers; and state and local regulations, incentives and financial markets. As a result, some regions would reduce the carbon intensity of their energy systems faster than others.
Credit: Amanda Montañez; Source: Marilyn A. Brown and Majid Ahmadi
Impact on Employment
We estimate that the more conservative $25 carbon tax would boost U.S. employment by 1.4 million jobs each year between 2020 and 2030, which is nearly a 1 percent increase above the reference–case forecast of 160 million jobs in 2030. As the economy expands and the tax increases, job growth from the GND would accelerate, creating, on average, 3.4 million new jobs each year between 2040 and 2050—a nearly 2 percent increase above the 182 million jobs forecast for the U.S. in 2050. Overall, it is estimated that 72 million job years would be created over the three decades with a $25 carbon tax. (Note that if one job continues after one year for another 12 months, it represents two job years.)
Credit: Amanda Montañez; Source: Marilyn A. Brown and Majid Ahmadi
With the more aggressive $60 carbon tax, U.S. employment would still exceed the reference-case forecast, but the increase would be less than that of the $25 tax. The higher tax causes much larger supply-side job losses, but they are still smaller than the gains in energy-efficiency jobs motivated by higher energy prices. Overall, 35 million job years would be created between 2020 and 2050, with net job increases in almost all regions.
Credit: Amanda Montañez; Source: Marilyn A. Brown and Majid Ahmadi
According to the latest data, in 2018 about 9.2 million Americans (5.7 percent of the U.S. workforce of roughly 162 million at the time) were employed in an energy industry. Nearly half of these jobs (about 4.3 million) made up the traditional supply-oriented categories: fuels, including petroleum, natural gas, coal and woody biomass (1.1 million); electric power generation (900,000); and transmission, distribution and storage (2.3 million). The motor-vehicle-related industries employed 2.5 million, and energy efficiency employed 2.4 million.
The GND would cause traditional supply-oriented jobs to decrease, but energy-efficiency jobs would more than compensate for the losses. New jobs from energy-efficiency investments would be significant, totaling 1.8 million in 2030 and 4.2 million in 2050. These estimates reflect the labor-intensity of jobs in construction, which account for more than half of the energy-efficiency workforce in 2018. Other large gains would be associated with heating, ventilation, air-conditioning and refrigeration systems—the largest share of energy-efficiency investments in the residential and commercial sectors. In industry, the greatest investments estimated would be in energy and environmental management and smart controls, followed by industrial-machinery manufacturing such as that of high-efficiency motors and variable-speed drives. The result would be job growth across all nine Census divisions of the U.S., in all three decades with a $25 carbon tax. The $60 tax would boost job growth in the U.S. overall and across a majority of its nine Census divisions and three decades.
Of the Census divisions, the Pacific and West North Central regions would be the only parts of the nation to experience job losses during both the 2020s and 2030s. The New England region is also projected to lose jobs during the first decade as it adjusts to the requirements of the $60 carbon tax. In contrast, West South Central and East North Central would witness the largest increase in energy-efficiency employment in both tax scenarios—and therefore would experience the largest job growth.
How large would the household dividends generated by taxes be? Imposing a $25 tax on each metric ton of CO 2 produced in the electricity sector alone would result in national revenue of $35 billion in 2020. A $60 tax would boost it to $68 billion. In aggregate, the resulting household income tax rebates, or “dividends,” would be greater than the increase in household utility bills. Nevertheless, the variation in dividends and bills would be regionally diverse. Dividends could be allocated uniformly across regions, but doing so would disadvantage regions with significant increases in energy prices.
Distributing dividends across households regardless of income, on the other hand, is a progressive feature of these proposed carbon-tax initiatives. High-income households purchase more carbon-intensive goods and services than other income groups. Therefore, low- and middle-income households would generally gain more in dividends than they would pay in increased prices from the introduction of carbon taxes.
Credit: Amanda Montañez; Source: Marilyn A. Brown and Majid Ahmadi
A Greener Economy Worth Investing In
The GND offers citizens a vision of how their economy could advance from traditional fossil-fuel dependence to a future powered largely by low-carbon alternatives. Our analysis indicates that a cleaner-energy approach motivated by carbon taxes would promote innovation, open up new markets and produce an economy with more jobs—a greener economy worth investing in.
Today clean-energy technologies in the U.S. struggle to compete because fossil energy is so “inexpensive.” Low prices make it difficult for such alternatives to flourish. Our analysis shows that raising energy prices would empower the transition to efficiency, renewables and other low-carbon resources. Indeed, a carbon tax of either $25 or $60 would cut carbon emissions significantly, but the higher tax would produce quicker and deeper reductions. On the other hand, while both tax levels would grow jobs, the $25 tax would provide more employment growth than the $60 one. Thus, as with most policies, the optimum is a trade-off between competing priorities.
By using the clean technologies that carbon taxes would promote, Americans would not have to travel less, freeze in the winter, take cold showers or cut the output of their manufacturing plants to reduce the U.S.’s carbon emissions. Our independent analysis, along with a growing body of research, suggests that a low-carbon economy is likely to be a stronger and more secure economy that also provides climate solutions.
Editor’s Note (12/19/19): This story was updated to include a graphic showing “Job Impacts by Sector.”


scientificamerican--2020-10-08--U.S. Wind and Solar Installation Are Smashing Records, But the Trend May Not Last

The United States is on pace to install record amounts of wind and solar this year , underscoring America 's capacity to build renewables at a level once considered impossible .
The U.S. Energy Information Administration expects the U.S. will install 37 gigawatts of new wind and solar capacity this year , obliterating the previous record of almost 17 GW in 2016 .
The renewable boom boosts U.S. climate efforts .
Energy modelers think the nation will need to deploy about 40 GW of wind and solar every year over the next decade to achieve deep decarbonization of its electric @ @ @ @ @ @ @ aberration or the beginning of a mass greening of the U.S. power sector depends in large part on what policymakers do next .
This year 's renewable energy expansion is driven in part by the expiration of the wind production tax credit and a decrease in the investment tax credit available to solar projects .
The last time the PTC expired , in 2012 , the U.S. installed a then record 13 GW of wind .
The next year , it failed to build a single gigawatt .
`` It is still worth @ @ @ @ @ @ @ who leads electricity research at Energy Innovation , a think tank that favors a transition to clean energy .
`` What I am worried about is can we replicate that success consistently , not to hit the record one time , but do it over and over again ? ''
The potential for a renewable energy drop-off points to the need for a national clean electricity standard or some other policy to drive green investments , he said .
`` We need a clear signal , '' O'Boyle added .
`` We ca @ @ @ @ @ @ @ of decimates the industry . ''
There are significant differences between now and a decade ago .
Most importantly , wind and solar are considerably cheaper .
The outlook for solar remains strong , with prices in the sector continuing to decline .
And in the case of wind , the industry has room to grow in large parts of the West .
But industry observers said the wind projects coming online this year will weigh on wholesale power prices in the markets where they are built , dragging down the incentive to @ @ @ @ @ @ @ .
Anthony Logan , an analyst who tracks power markets at Wood Mackenzie , said some of the wind projects anticipated to come online this year could be pushed off to 2021 .
EIA expects an additional 7.3 GW of new wind next year .
But the outlook for wind is significantly more challenged in the middle part of the decade , Logan said .
`` The depressed prices in high wind areas combined with the PTC rolling off create a dynamic where wind build is sharply curtailed , '' he said .
@ @ @ @ @ @ @ Much of the wind and solar development occurring this year is taking place in regions with large amounts of renewables already .
Texas , Iowa and Oklahoma ranked first , second and third , respectively , in total installed wind capacity in 2019 .
Those three states are expected to lead new wind installations again this year , accounting for 9.4 GW of the 23 GW expected to be installed .
California , meanwhile , continues to outpace most of the country in terms of new solar installations .
The Golden State is @ @ @ @ @ @ @ this year on top of the nation-leading 11 GW that 's already installed .
A total of 13.7 GW of solar is expected to come online nationally in 2020 .
Greening America 's collection of regional electric grids will not only require an expansion of renewables into new regions , but more transmission to carry it to the areas where power is consumed , analysts said .
`` We 're going to need more extension cords , '' said Steve Cicala , a professor who studies power markets at Tufts University .
Power @ @ @ @ @ @ @ generation are often low and can frequently turn negative because there is not enough transmission to export power to cities and other demand centers .
By contrast , power prices around cities are often higher due to transmission congestion , helping support fossil fuel plants that degrade air quality in urban areas .
`` If you can get the power from where it is being produced to where it is consumed , you can turn off those polluting power plants , '' Cicala said .
There are some notable exceptions to the regional @ @ @ @ @ @ @ install 3.3 GW of solar this year , a 36 % expansion , and add 5.9 GW more in the next two years .
The Lone Star State 's solar boom will help address concerns over inadequate electricity supplies to meet Texas ' summer demand peaks .
Those are now met in large part by fossil fuel plants , which ramp up as temperatures rise and air conditioners flick on .
Meeting large parts of that demand with solar will significantly green the Texas grid .
In the big picture , the amount @ @ @ @ @ @ @ will need to be replicated in coming years .
When Energy Innovation mapped out a pathway earlier this year for reducing power sector emissions 90 % by 2035 , it estimated the U.S. would need to add about 40 GW of renewables every year over the next decade .
A 2016 report by the Obama White House estimated renewable deployments of roughly 30 GW through 2035 were needed to achieve an 80 % reduction in emissions by 2050 .
`` One thing to think about with this surge is , yes , it @ @ @ @ @ @ @ quickly , '' said John Larsen , an analyst who tracks the power sector at the Rhodium Group , an economic research firm .
`` But we need to be able to continue to ramp . ''
Reprinted from Climatewire with permission from E & E News .
E & E provides daily coverage of essential energy and environmental news at www.eenews.net .

The United States is on pace to install record amounts of wind and solar this year, underscoring America's capacity to build renewables at a level once considered impossible.
The U.S. Energy Information Administration expects the U.S. will install 37 gigawatts of new wind and solar capacity this year, obliterating the previous record of almost 17 GW in 2016.
The renewable boom boosts U.S. climate efforts. Energy modelers think the nation will need to deploy about 40 GW of wind and solar every year over the next decade to achieve deep decarbonization of its electric grids.
But whether 2020 is an aberration or the beginning of a mass greening of the U.S. power sector depends in large part on what policymakers do next.
This year's renewable energy expansion is driven in part by the expiration of the wind production tax credit and a decrease in the investment tax credit available to solar projects. The last time the PTC expired, in 2012, the U.S. installed a then record 13 GW of wind. The next year, it failed to build a single gigawatt.
"It is still worth celebrating," said Mike O'Boyle, who leads electricity research at Energy Innovation, a think tank that favors a transition to clean energy. "What I am worried about is can we replicate that success consistently, not to hit the record one time, but do it over and over again?"
The potential for a renewable energy drop-off points to the need for a national clean electricity standard or some other policy to drive green investments, he said.
"We need a clear signal," O'Boyle added. "We can't afford another bust cycle that sort of decimates the industry."
There are significant differences between now and a decade ago. Most importantly, wind and solar are considerably cheaper.
The outlook for solar remains strong, with prices in the sector continuing to decline. And in the case of wind, the industry has room to grow in large parts of the West.
But industry observers said the wind projects coming online this year will weigh on wholesale power prices in the markets where they are built, dragging down the incentive to build new wind projects in future years.
Anthony Logan, an analyst who tracks power markets at Wood Mackenzie, said some of the wind projects anticipated to come online this year could be pushed off to 2021. EIA expects an additional 7.3 GW of new wind next year. But the outlook for wind is significantly more challenged in the middle part of the decade, Logan said.
"The depressed prices in high wind areas combined with the PTC rolling off create a dynamic where wind build is sharply curtailed," he said.
The challenges do not end there. Much of the wind and solar development occurring this year is taking place in regions with large amounts of renewables already.
Texas, Iowa and Oklahoma ranked first, second and third, respectively, in total installed wind capacity in 2019. Those three states are expected to lead new wind installations again this year, accounting for 9.4 GW of the 23 GW expected to be installed.
California, meanwhile, continues to outpace most of the country in terms of new solar installations. The Golden State is expected to add 2.3 GW of solar this year on top of the nation-leading 11 GW that's already installed. A total of 13.7 GW of solar is expected to come online nationally in 2020.
Greening America's collection of regional electric grids will not only require an expansion of renewables into new regions, but more transmission to carry it to the areas where power is consumed, analysts said.
"We're going to need more extension cords," said Steve Cicala, a professor who studies power markets at Tufts University.
Power prices in areas with lots of renewable generation are often low and can frequently turn negative because there is not enough transmission to export power to cities and other demand centers. By contrast, power prices around cities are often higher due to transmission congestion, helping support fossil fuel plants that degrade air quality in urban areas.
"If you can get the power from where it is being produced to where it is consumed, you can turn off those polluting power plants," Cicala said.
There are some notable exceptions to the regional trend. Texas is on pace to install 3.3 GW of solar this year, a 36% expansion, and add 5.9 GW more in the next two years.
The Lone Star State's solar boom will help address concerns over inadequate electricity supplies to meet Texas' summer demand peaks. Those are now met in large part by fossil fuel plants, which ramp up as temperatures rise and air conditioners flick on. Meeting large parts of that demand with solar will significantly green the Texas grid.
In the big picture, the amount of wind and solar deployed this year will need to be replicated in coming years.
When Energy Innovation mapped out a pathway earlier this year for reducing power sector emissions 90% by 2035, it estimated the U.S. would need to add about 40 GW of renewables every year over the next decade. A 2016 report by the Obama White House estimated renewable deployments of roughly 30 GW through 2035 were needed to achieve an 80% reduction in emissions by 2050.
"One thing to think about with this surge is, yes, it's doable. We can ramp up quickly," said John Larsen, an analyst who tracks the power sector at the Rhodium Group, an economic research firm. "But we need to be able to continue to ramp."
Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.


scientificamerican--2020-10-08--Last Chance for WIMPs: Physicists Launch All-Out Hunt for Dark-Matter Candidate

Physicists are hatching a plan to give a popular but elusive dark-matter candidate a last chance to reveal itself .
For decades , physicists have hypothesized that weakly interacting massive particles ( WIMPs ) are the strongest candidate for dark matter — the mysterious substance that makes up 85 % of the Universe ’ s mass .
But several experiments have failed to find evidence for WIMPs , meaning that , if they exist , their properties are unlike those originally predicted .
Now , researchers are pushing to build a final generation of supersensitive detectors — or one ‘ @ @ @ @ @ @ @ the particles no place to hide .
“ The WIMP hypothesis will face its real reckoning after these next-generation detectors run , ” says Mariangela Lisanti , a physicist at Princeton University in New Jersey .
Physicists have long predicted that an invisible substance , which has mass but doesn ’ t interact with light , permeates the Universe .
The gravitational effects of dark matter would explain why rotating galaxies don ’ t tear themselves apart , and the uneven pattern seen in the microwave ‘ afterglow ’ of the early Universe @ @ @ @ @ @ @ the dark matter in the 1980s .
They are typically predicted to be 1–1,000 times heavier than protons and to interact with matter only feebly — through the weak nuclear force , which is responsible for radioactive decay , or something even weaker .
Over the coming months , operations will begin at three existing underground detectors — in the United States , Italy and China — that search for dark-matter particles by looking for interactions in supercooled vats of xenon .
Using a method honed over more than a decade , these @ @ @ @ @ @ @ light when the nuclei recoil from their interaction with dark-matter particles .
Physicists hope that these experiments — or rival WIMP detectors that use materials such as germanium and argon — will make the first direct detection of dark matter .
But if this doesn ’ t happen , xenon researchers are already designing their ultimate WIMP detectors .
These experiments would probably be the last generation of their kind because they would be so sensitive that they would reach the ‘ neutrino floor ’ — a natural limit beyond which dark matter @ @ @ @ @ @ @ that its detection would be clouded by neutrinos , which barely interact with matter but rain down on Earth in their trillions every second .
“ It would be sort of crazy not to cover this gap , ” says Laura Baudis , a physicist at the University of Zurich in Switzerland .
“ Future generations may ask us , why didn ’ t you do this ?
” The most advanced of these efforts is a planned experiment called DARWIN .
The detector , estimated to cost between €100-million ( US $ @ @ @ @ @ @ @ being developed by the international XENON collaboration , which runs one of the 3 experiments starting up this year — a 6-tonne detector called XENONnT at the Gran Sasso National Laboratory near Rome .
DARWIN would contain almost ten times this volume of xenon .
Members of the collaboration have grants from several funding agencies to develop detector technology , including precise detection techniques that will work over DARWIN ’ s much larger scales , says Baudis , a leading member of XENON and co-spokesperson for DARWIN .
The project is also on @ @ @ @ @ @ @ future scientific infrastructure , and Germany ’ s research ministry has issued funding calls specifically for DARWIN-related research ; these steps suggest that the nations are likely to contribute further cash in the future .
And although DARWIN does not yet formally have a home , it could end up at Gran Sasso .
In April , the laboratory formally invited the collaboration to submit a conceptual design report by the end of 2021 .
“ It tells us very clearly that the lab is very interested in hosting such an experiment , @ @ @ @ @ @ @ physicist at the University of Freiburg in Germany .
The team hopes to be taking data by 2026 .
Although DARWIN is currently led by the XENON collaboration , Baudis is hopeful that Chinese colleagues , who this year are starting up an experiment called PandaX-4t , or the team involved in the US-based xenon experiment called Lux-Zeppelin , might join them in building a single ‘ ultimate ’ detector .
These teams have also considered building experiments that would take them to the neutrino floor , but “ the goal is , @ @ @ @ @ @ @ global xenon-based dark-matter experiment ” , says Baudis .
Physicists might have no choice but to club together because of the sheer quantity of xenon needed .
The noble gas is difficult to obtain in large quantities owing to the energy-intensive process needed to extract it from the air and because of competing demand from electronics , lighting and space industries .
One kilogram can cost more than US $ 2,500 .
Darwin ’ s 50 tonnes would be close to the world ’ s annual production of around 70 tonnes , meaning @ @ @ @ @ @ @ detectors combine their 25 tonnes — a future experiment would need to buy the rest in batches over several years .
“ We have to plan very carefully for it already now , ” says Baudis .
Researchers behind similar experiments that use argon to look for dark matter also hope to build a detector to reach the neutrino floor .
A 300-tonne experiment known as ARGO would likely begin operations around 2029 and could confirm any signal seen by DARWIN .
WIMPS have been the focus of dozens of experiments because there @ @ @ @ @ @ @ existence .
They not only explain why galaxies seem to move as they do , but their existence also fits with theories in particle physics .
A group of theories known as supersymmetry , devised in the 1970s to fill holes in physicists ’ standard model of fundamental particles and their interactions , predict a WIMP-like particle .
And when particle physicists model the early Universe , they find that particles with WIMP-like properties would survive the hot soup of interactions in just enough numbers to match the dark-matter abundance observed today .
@ @ @ @ @ @ @ detectors and from particle accelerators such as the Large Hadron Collider — mean that , if WIMPs exist , either the likelihood that they interact with matter or their mass must be at the lowest end of initial predictions .
The failure to detect WIMPs has caused the physics community to “ pause and reflect ” on their status , says Tien-Tien Yu , a physicist at the University of Oregon in Eugene .
Many in the physics community , including Yu , are now searching for other dark-matter candidates , including through @ @ @ @ @ @ @ WIMPs remain theoretically attractive enough to continue the decades-long hunt , says Yu .
And the DARWIN team emphasizes that its supersensitive detector would have myriad uses — including addressing the pressing questions in neutrino physics , says Baudis .
One mystery that DARWIN could help to solve is whether neutrinos are also their own antiparticle .
Whether a single experiment or many , “ I would bet quite some money that a DARWIN-like detector gets built , ” says Schumann .
This article is reproduced with permission and was first published on @ @ @ @

Physicists are hatching a plan to give a popular but elusive dark-matter candidate a last chance to reveal itself. For decades, physicists have hypothesized that weakly interacting massive particles (WIMPs) are the strongest candidate for dark matter — the mysterious substance that makes up 85% of the Universe’s mass. But several experiments have failed to find evidence for WIMPs, meaning that, if they exist, their properties are unlike those originally predicted. Now, researchers are pushing to build a final generation of supersensitive detectors — or one ‘ultimate’ detector — that will leave the particles no place to hide.
“The WIMP hypothesis will face its real reckoning after these next-generation detectors run,” says Mariangela Lisanti, a physicist at Princeton University in New Jersey.
Physicists have long predicted that an invisible substance, which has mass but doesn’t interact with light, permeates the Universe. The gravitational effects of dark matter would explain why rotating galaxies don’t tear themselves apart, and the uneven pattern seen in the microwave ‘afterglow’ of the early Universe. WIMPs became a favourite candidate for the dark matter in the 1980s. They are typically predicted to be 1–1,000 times heavier than protons and to interact with matter only feebly — through the weak nuclear force, which is responsible for radioactive decay, or something even weaker.
Supercooled xenon
Over the coming months, operations will begin at three existing underground detectors — in the United States, Italy and China — that search for dark-matter particles by looking for interactions in supercooled vats of xenon. Using a method honed over more than a decade, these detectors will watch for telltale flashes of light when the nuclei recoil from their interaction with dark-matter particles.
Physicists hope that these experiments — or rival WIMP detectors that use materials such as germanium and argon — will make the first direct detection of dark matter. But if this doesn’t happen, xenon researchers are already designing their ultimate WIMP detectors. These experiments would probably be the last generation of their kind because they would be so sensitive that they would reach the ‘neutrino floor’ — a natural limit beyond which dark matter would interact so little with xenon nuclei that its detection would be clouded by neutrinos, which barely interact with matter but rain down on Earth in their trillions every second. “It would be sort of crazy not to cover this gap,” says Laura Baudis, a physicist at the University of Zurich in Switzerland. “Future generations may ask us, why didn’t you do this?”
The most advanced of these efforts is a planned experiment called DARWIN. The detector, estimated to cost between €100-million (US$116-million) and €150 million, is being developed by the international XENON collaboration, which runs one of the 3 experiments starting up this year — a 6-tonne detector called XENONnT at the Gran Sasso National Laboratory near Rome. DARWIN would contain almost ten times this volume of xenon. Members of the collaboration have grants from several funding agencies to develop detector technology, including precise detection techniques that will work over DARWIN’s much larger scales, says Baudis, a leading member of XENON and co-spokesperson for DARWIN.
Global experiment
The project is also on Switzerland’s national road map for future scientific infrastructure, and Germany’s research ministry has issued funding calls specifically for DARWIN-related research; these steps suggest that the nations are likely to contribute further cash in the future. And although DARWIN does not yet formally have a home, it could end up at Gran Sasso. In April, the laboratory formally invited the collaboration to submit a conceptual design report by the end of 2021. “It tells us very clearly that the lab is very interested in hosting such an experiment,” says co-spokesperson Marc Schumann, a physicist at the University of Freiburg in Germany. The team hopes to be taking data by 2026.
Although DARWIN is currently led by the XENON collaboration, Baudis is hopeful that Chinese colleagues, who this year are starting up an experiment called PandaX-4t, or the team involved in the US-based xenon experiment called Lux-Zeppelin, might join them in building a single ‘ultimate’ detector. These teams have also considered building experiments that would take them to the neutrino floor, but “the goal is, of course, to have one large global xenon-based dark-matter experiment”, says Baudis.
Physicists might have no choice but to club together because of the sheer quantity of xenon needed. The noble gas is difficult to obtain in large quantities owing to the energy-intensive process needed to extract it from the air and because of competing demand from electronics, lighting and space industries. One kilogram can cost more than US$2,500. Darwin’s 50 tonnes would be close to the world’s annual production of around 70 tonnes, meaning that — even if all 3 existing detectors combine their 25 tonnes — a future experiment would need to buy the rest in batches over several years. “We have to plan very carefully for it already now,” says Baudis.
Researchers behind similar experiments that use argon to look for dark matter also hope to build a detector to reach the neutrino floor. A 300-tonne experiment known as ARGO would likely begin operations around 2029 and could confirm any signal seen by DARWIN.
Why WIMPs?
WIMPS have been the focus of dozens of experiments because there is a strong theoretical case for their existence. They not only explain why galaxies seem to move as they do, but their existence also fits with theories in particle physics. A group of theories known as supersymmetry, devised in the 1970s to fill holes in physicists’ standard model of fundamental particles and their interactions, predict a WIMP-like particle. And when particle physicists model the early Universe, they find that particles with WIMP-like properties would survive the hot soup of interactions in just enough numbers to match the dark-matter abundance observed today.
But null results — from direct dark-matter detectors and from particle accelerators such as the Large Hadron Collider — mean that, if WIMPs exist, either the likelihood that they interact with matter or their mass must be at the lowest end of initial predictions. The failure to detect WIMPs has caused the physics community to “pause and reflect” on their status, says Tien-Tien Yu, a physicist at the University of Oregon in Eugene. Many in the physics community, including Yu, are now searching for other dark-matter candidates, including through smaller, cheaper experiments.
Still, WIMPs remain theoretically attractive enough to continue the decades-long hunt, says Yu. And the DARWIN team emphasizes that its supersensitive detector would have myriad uses — including addressing the pressing questions in neutrino physics, says Baudis. One mystery that DARWIN could help to solve is whether neutrinos are also their own antiparticle.
Whether a single experiment or many, “I would bet quite some money that a DARWIN-like detector gets built,” says Schumann.
This article is reproduced with permission and was first published on October 2 2020.