iowaclimatescienceeducation--2020-03-25--Lunar Recession and the Age of the Earth: How Uniformitarianism Works

One of the things I love about writing for Watts Up With That , is the fact that reader comments often inspire me to research and write subsequent posts .
In my recent post about the origins of the Moon , one commentator suggested that the rate of lunar recession ( tidal acceleration ) indicated that the Earth was much younger than 4.5 billion years old and/or somehow disproved the geological Principle of Uniformitarianism .
I didn ’ t give much thought to my reply .
I simply calculated the distance from the Earth to the Moon 1 billion and @ @ @ @ @ @ @ is currently receding ( moving away ) from the Earth at a rate of about 3.8 cm/yr .
This has been directly measured with lasers .
At 3.8 cm/yr , the Moon would have been 215,288 miles away from Earth a billion years ago .
It is currently an average of 238,900 miles away .
At 3.8 cm/yr , it still would have been 132,646 miles away 4.5 BY .
If the Moon did did originate from a collision with Earth , it would have been a lost closer to Earth 4.5 BY @ @ @ @ @ @ @ , 215,288 miles apart didn ’ t seem problematic .
It is well outside the Earth-Moon Roche Radius , however , at a steady rate of 3.8 cm/yr , the Moon ’ s orbit would have been close enough to Earth , that 1.5 billion years ago , the tidal forces of the Earth-Moon system may yielded catastrophic results : Apart from the classic bad science fiction movie , 2012 , or the junk science of Hapgood and Velikovsky , there is no evidence whatsoever , of lunar disruption or the total melting @ @ @ @ @ @ @ years ago .
So… How do we solve this conundrum ?
We solve it by applying the principle of Uniformitarianism .
Most criticisms of Uniformitarianism start out with a fundamental misunderstanding of , or the intentional redefinition of , this basic geological principle .
Initial thinking on earth history was inspired by the bible .
The recognition that major rock series are characterized by a distinct set of fossils lead to the belief that the fossils of each rock series were result of a creation and then were subsequently destroyed by some catastrophic @ @ @ @ @ @ @ ) .
The main proponent of this theory was the French naturalist Georges Cuvier .
In the 18th century there was even a case when some unfortunate geologist ( Johann Jacob Scheuchzer , 1672-1733 ) found skeletons of giant salamanders and identified them as the victims of the biblical flood .
The problem was that upon close inspection , these flood victims had long tails and sharp claws .
Thus , it earned the proponent quite a bit of ridicule .
Generally speaking , this way of looking at the geologic record , @ @ @ @ @ @ @ immense , brief , and worldwide upheavals changed the earth greatly and produced mountains , valleys , and various other large scale features , came to be known as catastrophism .
The theory of catastrophism was challenged by James Hutton in the late 18th century , who in his theory of uniformitarianism proposed that uniform gradual processes ( such as for example the slow erosion of the coast by the impact of waves ) shaped the geologic record of the earth over an immensely long period of time .
He assumed that the @ @ @ @ @ @ @ that we see in action at present ( rivers , volcanoes , waves , tides etc. )
.
Darwin later on based his theory of the origin a species on Hutton ’ s theory .
The sedimentary structures that we saw earlier in this lecture serve as a good illustration how uniformitarianism works .
Cross-bedding for example can be observed to form in modern river channels and also in experimental setups called flumes .
We learn from these observations what kind of current velocities are needed to produce cross-bedding in a given grain @ @ @ @ @ @ @ can be used as an indicator of current flow direction .
We can apply what we learn from modern cross-beds to interpret the rock record in terms of flow velocities and flow direction .
Likewise , finding ancient equivalents of modern mudcracks suggests to us that we look at sediments that dried out beneath the air , and were thus deposited on land .
In more modern times , some amendments have been made to the theory of uniformitarianism .
One of these would be that it was recognized that catastrophic events are @ @ @ @ @ @ @ the uniform action of the everyday processes .
For example , sediment supply to the oceans is not a constant flux of matter .
There is a considerable episodic component to sedimentation , e.g .
storms are major agents of sediment redistribution in shelf seas , floods and exceptionally strong rains are responsible for most of the erosion and sediment redistribution on the continents .
Undoubtedly , the physical and chemical principles ( e.g .
gravity , thermodynamics ) that govern geologic processes of the present have also applied in the past .
@ @ @ @ @ @ @ , frequent small deviations from equilibrium and unstable behavior ( minor catastrophes , such as earthquakes , floods , storms ) must have been an integral part of these processes .
Similarly , the evolution of life was not a single succession of tiny evolutionary steps as originally envisioned by Darwin .
We are now able to see that there were episodes of accelerated ( punctuated ) evolution , usually as a response to a change in environmental conditions , such as climate ( ice ages , warming of the earth ) , @ @ @ @ @ @ @ and the utilization of new food sources .
Extremely rare ( and catastrophic ) events , such as the impact of large meteors , may have had a profound influence on our planet .
Yet meteors fall onto the earth on a daily basis , just as it rains every day .
In that sense , meteorite impacts are quite normal and part of the spectrum of everyday processes .
Only very rarely does a “ doomsday ” meteorite that is 10 or more km in diameter hit the Earth and cause severe @ @ @ @ @ @ @ The natural laws do not change with time and they have and will determine interior and external processes of the earth .
Even the extremely rare event ( e.g .
meteor impacts ) is part of the many geologic processes governed by these laws .
Even though something , like for example the December 2004 tsunami , appears to us as a unique catastrophe , over the long run it is a normal and recurring event .
It does not follow , however , that the rate of geologic processes is the same @ @ @ @ @ @ @ .
Some processes , such as mantle convection do probably stay stable over long time periods , but others , such as glaciation were at times very intense in the past ( ice ages ) , but are presently less significant for continental erosion .
So , a brief definition of Uniformitarianism would be : the natural laws that govern geologic processes have not changed over geologic time , but the rate at which certain geologic processes operate can vary .
Uniformitarianism also has been paraphrased as “ The Present is the Key @ @ @ @ @ @ @ ’ t preclude catastrophic events ; nor does it stipulate that all processes must occur at a constant gradual rate .
And it certainly doesn ’ t blind geologists to actual evidence of past catastrophic events , like impact features .
Many of the world ’ s 190 confirmed impact craters ( technically 189 because they count Upheaval Dome as confirmed ) would be unknown if not for geologists employing uniformitarian methods to identify them .
34 % of the confirmed impact craters are not exposed at the surface .
53 % of @ @ @ @ @ @ @ , either intentionally or inadvertently while drilling for something else .
The craters without surface expressions were identified by uniformitarian geologists/geophysicists interpreting geological and geophysical data .
Uniformitarianism says “ The Present is the Key to the Past.
” Understanding present day geological processes enables geologists to decipher the geologic past .
It enables us to translate the language of the rocks .
So , what does this have to do with lunar recession ?
Tidal rhymites are the result of very high frequency depositional cycles .
The length of the day , @ @ @ @ @ @ @ and months in the year can all be calculated from tidal rhythmites .
Fortunately for geologists , Earth was kind enough to preserve at least a few very old tidal rhythmite deposits .
This tour begins 1 billion years ago when the area was a tidal environment at an ocean shoreline .
The tidal environment is preserved in the now-tilted layers of quartzite and shale that make up the canyon walls for the first 6 miles .
In some areas , the shale is metamorphosed into argillite or slate .
Tidal Rhythmites One-billion-year-old @ @ @ @ @ @ @ tides One of the best documented and oldest known records worldwide of tidal rhythmites is in Big Cottonwood Canyon .
Discovered in the 1990s , this record is enthusiastically being researched , in large part to provide clues to ancient lunar cycles .
Yearly , monthly , and even daily and semi-daily tides are recorded in the black shale of the 850-million to 1-billion-year-old Big Cottonwood Formation .
Within the shale are thin , alternating layers of light-colored sand and dark-colored silt and clay .
The sand was carried by peak ( strong @ @ @ @ @ @ @ and clay by slack ( weaker , subordinate ) waters at changing tides .
Thus , these thin individual bands record daily tides and can be counted much like we count tree rings .
Because the gravitational pull of the moon and the sun cause tides , the length of an ancient day and lunar month can be determined from these tidal rhythmites .
Long ago , the moon took less time to orbit the Earth , the Earth was spinning faster , and thus the days were shorter and there were more @ @ @ @ @ @ @ records in stone indicate that one billion years ago , a day on Earth lasted only 18 hours , there were 13-plus months in a year , and about 481 days in a year !
( Information supplied by Marjorie A. Chan , University of Utah and Allen W. Archer , Kansas State University ) .
Tidal rhyhmites and other paleontological data tell us that the days have been getting longer , while the number of days per year have been decreasing over the past 500 million years .
Tidal rhymite formations enable @ @ @ @ @ @ @ Earth ’ s rotation and lunar orbit ” ( Williams , 1990 ) over the past 2.5 billion years .
The recent recognition of cyclically laminated tidal rhythmites provides a new approach to tracing the dynamic history of the Earth-Moon system .
Late Proterozoic ( ~650 Ma ) elastic rhythmites in South Australia represent an unsurpassed palaeotidal record of ~560 years ’ duration that provides numerous palaeorotational parameters .
At~650 Ma there were 13.1 ±0.1 lunar months/year , 400 ±7 solar days/year , and 30.5 ±0.5 solar days/lunar month .
The lunar apsides @ @ @ @ @ @ @ ±0.1 years and 19.5 ±0.5 years , respectively .
The indicated mean Earth-Moon distance of 58.28 ±0.30 Earth radii at ~650 Ma gives a mean rate of lunar retreat of 1.95 ±0.29 cm/year since that time , about half the present rate of lunar retreat of 3.7 ±0.2 cm/year obtained by lunar laser ranging .
The rhythmite data imply a substantial obliquity of the ecliptic at ~650 Ma , and indicate virtually no overall change in the Earth ’ s moment of inertia , which militates against significant Earth expansion since ~650 Ma @ @ @ @ @ @ @ cyclic banded iron-formation in Western Australia , that may record submarine fumarolic activity triggered by earth tides , suggests ~14.5 ±0.5 lunar months/year and a mean Earth-Moon distance of ~54.6 Earth radii at ~2,500 Ma .
The combined rhythmite data suggest a mean rate of lunar retreat of ~1.27 cm/year during the Proterozoic ( ~2,500-650 Ma ) ; the indicated increasing mean rate of lunar retreat since~2,500 Ma is consistent with increasing oceanic tidal dissipation as the Earth ’ s rotation slows .
A close approach of the Moon during earlier time is @ @ @ @ @ @ @ promises to further illuminate the evolving dynamics of the Earth-Moon system .
The rate of lunar recession was highly variable during the Proterozoic Eon .
The closest the closest approach of the Moon ’ s orbit to the Earth , as estimated from Precambrian tidal rhymites was ~51.9 Earth radii ( ~206,000 miles ) approximately 2.45 billion years ago .
Green et al.
, 2017 indicate that the modern recession rate is anomalously high , about twice the average of the Proterozoic Eon .
However , the rate appears the have even been @ @ @ @ @ @ @ the Pleistocene Epoch ’ s Last Glacial Maximum .
Science starts with observations ( what we know ) and then works to form hypotheses to explain the observations .
The hypotheses are then tested to see if they can become scientific theories .
Ideally , the hypotheses are tested empirically , in controlled experiments .
Unfortunately , in geology , most hypothesis can only be tested by gathering more observations .
This is why Chamberlin ’ s Method of Multiple Working Hypotheses is taught by many geology departments .
For every given set @ @ @ @ @ @ @ , almost invariably , multiple working hypotheses ( non-uniqueness ) .
As more observations are collected , some hypotheses will survive , others will have to be modified or discarded .
In the case of lunar recession , we started out with two observations : • The Moon has been receding from the Earth at a rate of 3.8 cm/yr .
• The Earth and the Moon are approximately 4.5 billion years old .
We know the current recession rate from decades of laser ranging .
While the ages of the Earth and @ @ @ @ @ @ @ as much certainty as the lunar recession rate , radiometric dating precludes them from being significantly younger than 4.5 billion years old .
At first glance , the physical cause of the first observation would seem to contradict the second observation .
This means that either : 1 ) the recession rate was much slower in the past or 2 ) the Earth and Moon are less than 1.5 billion years old .
Since we can ’ t run a controlled experiment , the best we can do is to see if the @ @ @ @ @ @ @ recession rates .
The rocks tell us that modern recession rate is anomalously high , and that the Moon ’ s orbit has not been catastrophically close to Earth at any point in the past 2.45 billion years .
Without the Principle of Uniformitarianism , geologists wouldn ’ t be able to “ translate the language ” of the rocks .
Hat tip to hiskorr for his ( or her ) comments .
I had never given this subject any thought before .
I actually found it quite interesting when I started digging @ @ @ @ @ @ @ Commissioner Clay Jenkins issued a “ shelter in place ” order for Dallas County .
Judge Jenkins , a liberal Democrat , looks like Howdy Doody and talks like Forrest Gump .
The latest numbers indicate that there are 169 CHICOM-19 cases in Dallas County , and there have been 5 deaths .
Dallas County has a population of 2,637,767 people .
99.9936 % of Dallas County does not have CHICOM-19 and 99.9998 % of us haven ’ t died from it .
The shelter in place order means that I get to @ @ @ @ @ @ @ two weeks .
So , I set up my work station on the island in our kitchen and have the TV on .
The other day I watched The Big Lebowsky while I was working in the shorts and tee-shirt that I had slept in , wearing slippers .
I could get used to this .
Meetings are much more fun this way .
Instead of a conference room , we get to WebEx and see our co-workers at home in shorts and flip-flops .
The shelter in place order only allows essential @ @ @ @ @ @ @ oddly , includes liquor stores ( Hoo-Ahh ! )
.
As nearly as I can tell , most white collar workers have been told to work from home , if possible , while the businesses that mainly hire illegal aliens appear to be unaffected .
Green , Mattias & Huber , M. & Waltham , D. & Buzan , Jonathan & Wells , Martin .
( 2017 ) .
“ Explicitly modelled deep-time tidal dissipation and its implication for Lunar history .
” Earth and Planetary Science Letters .
461 .
46-53 .
@ @ @ @ @ @ @ “ Tidal rhythmites : Key to the history of the Earth ’ s rotation and the lunar o ” rbit ” , J. Phys .
Earth , 38 , 475-491 , 1990 .
Williams , G.E .
Geological Constraints on the Precambrian History of Earth ’ s Rotation and the Moon ’ s Orbit , Reviews of Geophysics 38 ( 2000 ) , 37-59 .

Guest “geology lessons” by David Middleton
One of the things I love about writing for Watts Up With That, is the fact that reader comments often inspire me to research and write subsequent posts. In my recent post about the origins of the Moon, one commentator suggested that the rate of lunar recession (tidal acceleration) indicated that the Earth was much younger than 4.5 billion years old and/or somehow disproved the geological Principle of Uniformitarianism. I didn’t give much thought to my reply. I simply calculated the distance from the Earth to the Moon 1 billion and 4.5 billion years ago. The Moon is currently receding (moving away) from the Earth at a rate of about 3.8 cm/yr. This has been directly measured with lasers.
At 3.8 cm/yr, the Moon would have been 215,288 miles away from Earth a billion years ago. It is currently an average of 238,900 miles away. At 3.8 cm/yr, it still would have been 132,646 miles away 4.5 BY. If the Moon did did originate from a collision with Earth, it would have been a lost closer to Earth 4.5 BY than 100,000 miles. David Middleton
At first thought, 215,288 miles apart didn’t seem problematic. It is well outside the Earth-Moon Roche Radius, however, at a steady rate of 3.8 cm/yr, the Moon’s orbit would have been close enough to Earth, that 1.5 billion years ago, the tidal forces of the Earth-Moon system may yielded catastrophic results:
Tracing the history of Earth’s tidal deceleration and the evolution of the Moon’s orbit is a major challenge for geology. The implications of employing the present rate of tidal energy dissipation on a geological timescale are catastrophic: Around 1500 Ma the Moon would have been close to Earth, with the consequence that the much larger tidal forces would have disrupted the Moon or caused the total melting of Earth’s mantle and of the Moon [Lambeck, 1980]. Williams, 2000
Apart from the classic bad science fiction movie, 2012, or the junk science of Hapgood and Velikovsky, there is no evidence whatsoever, of lunar disruption or the total melting of Earth’s mantle 1.5 billion years ago.
So… How do we solve this conundrum? We solve it by applying the principle of Uniformitarianism.
Most criticisms of Uniformitarianism start out with a fundamental misunderstanding of, or the intentional redefinition of, this basic geological principle.
UNIFORMITARIANISM VS CATASTROPHISM Initial thinking on earth history was inspired by the bible. The recognition that major rock series are characterized by a distinct set of fossils lead to the belief that the fossils of each rock series were result of a creation and then were subsequently destroyed by some catastrophic event (e.g. the biblical flood). The main proponent of this theory was the French naturalist Georges Cuvier. In the 18th century there was even a case when some unfortunate geologist (Johann Jacob Scheuchzer, 1672-1733) found skeletons of giant salamanders and identified them as the victims of the biblical flood. The problem was that upon close inspection, these flood victims had long tails and sharp claws. Thus, it earned the proponent quite a bit of ridicule. Generally speaking, this way of looking at the geologic record, namely to assume that a series of immense, brief, and worldwide upheavals changed the earth greatly and produced mountains, valleys, and various other large scale features, came to be known as catastrophism. The theory of catastrophism was challenged by James Hutton in the late 18th century, who in his theory of uniformitarianism proposed that uniform gradual processes (such as for example the slow erosion of the coast by the impact of waves) shaped the geologic record of the earth over an immensely long period of time. He assumed that the acting processes were the same than those that we see in action at present (rivers, volcanoes, waves, tides etc.). Darwin later on based his theory of the origin a species on Hutton’s theory. The sedimentary structures that we saw earlier in this lecture serve as a good illustration how uniformitarianism works. Cross-bedding for example can be observed to form in modern river channels and also in experimental setups called flumes. We learn from these observations what kind of current velocities are needed to produce cross-bedding in a given grain size, and we realize that cross-bedding can be used as an indicator of current flow direction. We can apply what we learn from modern cross-beds to interpret the rock record in terms of flow velocities and flow direction. Likewise, finding ancient equivalents of modern mudcracks suggests to us that we look at sediments that dried out beneath the air, and were thus deposited on land. In more modern times, some amendments have been made to the theory of uniformitarianism. One of these would be that it was recognized that catastrophic events are as much part of geologic history as the uniform action of the everyday processes. For example, sediment supply to the oceans is not a constant flux of matter. There is a considerable episodic component to sedimentation, e.g. storms are major agents of sediment redistribution in shelf seas, floods and exceptionally strong rains are responsible for most of the erosion and sediment redistribution on the continents. Undoubtedly, the physical and chemical principles (e.g. gravity, thermodynamics) that govern geologic processes of the present have also applied in the past. Yet as is visible in the present, frequent small deviations from equilibrium and unstable behavior (minor catastrophes, such as earthquakes, floods, storms) must have been an integral part of these processes. Similarly, the evolution of life was not a single succession of tiny evolutionary steps as originally envisioned by Darwin. We are now able to see that there were episodes of accelerated (punctuated) evolution, usually as a response to a change in environmental conditions, such as climate (ice ages, warming of the earth), the advent or immigration of new predators and the utilization of new food sources. Extremely rare (and catastrophic) events, such as the impact of large meteors, may have had a profound influence on our planet. Yet meteors fall onto the earth on a daily basis, just as it rains every day. In that sense, meteorite impacts are quite normal and part of the spectrum of everyday processes. Only very rarely does a “doomsday” meteorite that is 10 or more km in diameter hit the Earth and cause severe disruptions. To sum it up: The natural laws do not change with time and they have and will determine interior and external processes of the earth. Even the extremely rare event (e.g. meteor impacts) is part of the many geologic processes governed by these laws. Even though something, like for example the December 2004 tsunami, appears to us as a unique catastrophe, over the long run it is a normal and recurring event. It does not follow, however, that the rate of geologic processes is the same today as it was in the past. Some processes, such as mantle convection do probably stay stable over long time periods, but others, such as glaciation were at times very intense in the past (ice ages), but are presently less significant for continental erosion. So, a brief definition of Uniformitarianism would be: the natural laws that govern geologic processes have not changed over geologic time, but the rate at which certain geologic processes operate can vary. Uniformitarianism also has been paraphrased as “The Present is the Key to the Past“. Indiana University
Uniformitarianism doesn’t preclude catastrophic events; nor does it stipulate that all processes must occur at a constant gradual rate. And it certainly doesn’t blind geologists to actual evidence of past catastrophic events, like impact features. Many of the world’s 190 confirmed impact craters (technically 189 because they count Upheaval Dome as confirmed) would be unknown if not for geologists employing uniformitarian methods to identify them. 34% of the confirmed impact craters are not exposed at the surface. 53% of the confirmed impact craters have been drilled, either intentionally or inadvertently while drilling for something else. The craters without surface expressions were identified by uniformitarian geologists/geophysicists interpreting geological and geophysical data.
Uniformitarianism says “The Present is the Key to the Past.” Understanding present day geological processes enables geologists to decipher the geologic past. It enables us to translate the language of the rocks.
So, what does this have to do with lunar recession?
Two words: Tidal Rhymites
The sedimentary record in Muir Inlet, a macrotidal fjord in Alaska, is dominated by cyclic silt–mud rhythmites. Couplet thicknesses vary systematically in a vertical sequence and reflect a semidiurnal tidal regime. Semimonthly, monthly, bimonthly, and annual cycles can be identified both visually in cores and by spectral frequency analysis. An average annual sedimentation of 22.5 cmyr-1 occurs over a four-month meltwater season and is confirmed by 210Pb dating. These modern deep-water tidal rhythmites can be used to verify interpretations made on ancient rhythmites in the stratigraphic record, and they also provide a dating tool to interpret high latitude successions for high-resolution climate change. Cowan et al., 1998
Tidal rhymites are the result of very high frequency depositional cycles. The length of the day, the number of days in the month and months in the year can all be calculated from tidal rhythmites. Fortunately for geologists, Earth was kind enough to preserve at least a few very old tidal rhythmite deposits.
BIG COTTONWOOD CANYON By Sandra Eldredge This tour begins 1 billion years ago when the area was a tidal environment at an ocean shoreline. The tidal environment is preserved in the now-tilted layers of quartzite and shale that make up the canyon walls for the first 6 miles. In some areas, the shale is metamorphosed into argillite or slate. […] Tidal Rhythmites
One-billion-year-old records of the rhythm of ancient ocean tides One of the best documented and oldest known records worldwide of tidal rhythmites is in Big Cottonwood Canyon. Discovered in the 1990s, this record is enthusiastically being researched, in large part to provide clues to ancient lunar cycles. Yearly, monthly, and even daily and semi-daily tides are recorded in the black shale of the 850-million to 1-billion-year-old Big Cottonwood Formation. Within the shale are thin, alternating layers of light-colored sand and dark-colored silt and clay. The sand was carried by peak (strong, dominant) flows and the silt and clay by slack (weaker, subordinate) waters at changing tides. Thus, these thin individual bands record daily tides and can be counted much like we count tree rings. Because the gravitational pull of the moon and the sun cause tides, the length of an ancient day and lunar month can be determined from these tidal rhythmites. Long ago, the moon took less time to orbit the Earth, the Earth was spinning faster, and thus the days were shorter and there were more of them in a year. These records in stone indicate that one billion years ago, a day on Earth lasted only 18 hours, there were 13-plus months in a year, and about 481 days in a year! (Information supplied by Marjorie A. Chan, University of Utah and Allen W. Archer, Kansas State University). Utah Geological Survey
Tidal rhyhmites and other paleontological data tell us that the days have been getting longer, while the number of days per year have been decreasing over the past 500 million years.
Figure 2 from Williams, 2000.
Tidal rhymite formations enable geologists to reconstruct “the history of Earth’s rotation and lunar orbit” (Williams, 1990) over the past 2.5 billion years.
The recent recognition of cyclically laminated tidal rhythmites provides a new approach to tracing the dynamic history of the Earth-Moon system. Late Proterozoic (~650 Ma) elastic rhythmites in South Australia represent an unsurpassed palaeotidal record of ~560 years’ duration that provides numerous palaeorotational parameters. At~650 Ma there were 13.1 ±0.1 lunar months/year, 400 ±7 solar days/year, and 30.5 ±0.5 solar days/lunar month. The lunar apsides and lunar nodal cycles were then 9.7 ±0.1 years and 19.5 ±0.5 years, respectively. The indicated mean Earth-Moon distance of 58.28 ±0.30 Earth radii at ~650 Ma gives a mean rate of lunar retreat of 1.95 ±0.29 cm/year since that time, about half the present rate of lunar retreat of 3.7 ±0.2 cm/year obtained by lunar laser ranging. The rhythmite data imply a substantial obliquity of the ecliptic at ~650 Ma, and indicate virtually no overall change in the Earth’s moment of inertia, which militates against significant Earth expansion since ~650 Ma. Early Proterozoic ( ~2,500 Ma) cyclic banded iron-formation in Western Australia, that may record submarine fumarolic activity triggered by earth tides, suggests ~14.5 ±0.5 lunar months/year and a mean Earth-Moon distance of ~54.6 Earth radii at ~2,500 Ma. The combined rhythmite data suggest a mean rate of lunar retreat of ~1.27 cm/year during the Proterozoic (~2,500-650 Ma); the indicated increasing mean rate of lunar retreat since~2,500 Ma is consistent with increasing oceanic tidal dissipation as the Earth’s rotation slows. A close approach of the Moon during earlier time is uncertain. Continued study of tidal rhythmites promises to further illuminate the evolving dynamics of the Earth-Moon system. Williams, 1990
The rate of lunar recession was highly variable during the Proterozoic Eon. The closest the closest approach of the Moon’s orbit to the Earth, as estimated from Precambrian tidal rhymites was ~51.9 Earth radii (~206,000 miles) approximately 2.45 billion years ago.
Table 1 from Williams, 2000.
Green et al., 2017 indicate that the modern recession rate is anomalously high, about twice the average of the Proterozoic Eon. However, the rate appears the have even been higher than it currently is, during the Pleistocene Epoch’s Last Glacial Maximum.
Conclusions
Science starts with observations (what we know) and then works to form hypotheses to explain the observations. The hypotheses are then tested to see if they can become scientific theories. Ideally, the hypotheses are tested empirically, in controlled experiments. Unfortunately, in geology, most hypothesis can only be tested by gathering more observations. This is why Chamberlin’s Method of Multiple Working Hypotheses is taught by many geology departments. For every given set of Earth Science observations, there are, almost invariably, multiple working hypotheses (non-uniqueness). As more observations are collected, some hypotheses will survive, others will have to be modified or discarded.
In the case of lunar recession, we started out with two observations:
The Moon has been receding from the Earth at a rate of 3.8 cm/yr. The Earth and the Moon are approximately 4.5 billion years old.
We know the current recession rate from decades of laser ranging. While the ages of the Earth and the Moon aren’t known with as much certainty as the lunar recession rate, radiometric dating precludes them from being significantly younger than 4.5 billion years old.
At first glance, the physical cause of the first observation would seem to contradict the second observation. This means that either: 1) the recession rate was much slower in the past or 2) the Earth and Moon are less than 1.5 billion years old. Since we can’t run a controlled experiment, the best we can do is to see if the rocks can tell us anything about past recession rates. The rocks tell us that modern recession rate is anomalously high, and that the Moon’s orbit has not been catastrophically close to Earth at any point in the past 2.45 billion years. Without the Principle of Uniformitarianism, geologists wouldn’t be able to “translate the language” of the rocks.
Hat tip to hiskorr for his (or her) comments.
I had never given this subject any thought before. I actually found it quite interesting when I started digging into it.
Day 9 of America Held Hostage by CHICOM-19
Yesterday, Dallas County Commissioner Clay Jenkins issued a “shelter in place” order for Dallas County. Judge Jenkins, a liberal Democrat, looks like Howdy Doody and talks like Forrest Gump. The latest numbers indicate that there are 169 CHICOM-19 cases in Dallas County, and there have been 5 deaths. Dallas County has a population of 2,637,772 2,637,767 people.
Dallas County CHICOM-190 Population Cases Deaths 2,637,772 169 5 % of population 0.0064% 0.00019%
99.9936% of Dallas County does not have CHICOM-19 and 99.9998% of us haven’t died from it.
The shelter in place order means that I get to work from home for at least another two weeks. So, I set up my work station on the island in our kitchen and have the TV on. The other day I watched The Big Lebowsky while I was working in the shorts and tee-shirt that I had slept in, wearing slippers. I could get used to this. Meetings are much more fun this way. Instead of a conference room, we get to WebEx and see our co-workers at home in shorts and flip-flops.
The shelter in place order only allows essential businesses to remain open, which, oddly, includes liquor stores (Hoo-Ahh!). As nearly as I can tell, most white collar workers have been told to work from home, if possible, while the businesses that mainly hire illegal aliens appear to be unaffected.
References
Cowan, E., Cai, J., Powell, R. et al. Modern tidal rhythmites deposited in a deep-water estuary. Geo-Marine Letters 18, 40–48 (1998). https://ift.tt/33HRIU5
Green, Mattias & Huber, M. & Waltham, D. & Buzan, Jonathan & Wells, Martin. (2017). “Explicitly modelled deep-time tidal dissipation and its implication for Lunar history. ” Earth and Planetary Science Letters. 461. 46-53. 10.1016/j.epsl.2016.12.038.
Williams, G. E., “Tidal rhythmites: Key to the history of the Earth’s rotation and the lunar o”rbit”, J. Phys. Earth, 38, 475-491, 1990.
Williams, G.E. Geological Constraints on the Precambrian History of Earth’s Rotation and the Moon’s Orbit, Reviews of Geophysics 38 (2000), 37-59.


iowaclimatescienceeducation--2020-03-25--Antarctica set its coldest EVER March temperature (-103.5F)

Somehow , while we ’ re supposed to believe the world is on the brink of “ overheating ” , @ @ @ @ @ continent is currently the coldest its ever been for the time of year .
Last @ @ @ @ @ record for its coldest March temp ever recorded , not just for the day , @ @ @ @ @ .
The Vostok Station clocked a bone-chilling -75.3C ( -103.54F ) on the morning of @ @ @ @ @ as spotted by @ TempGlobal on Twitter : Thanks to Bill Sellers for this link @ @ @ @ @ coldest EVER March temperature ( -103.5F ) appeared first on Ice Age Now .

Somehow, while we’re supposed to believe the world is on the brink of “overheating”, the world’s southernmost continent is currently the coldest its ever been for the time of year.
Last Friday, Antarctica set a record for its coldest March temp ever recorded, not just for the day, but for the entire month.
The Vostok Station clocked a bone-chilling -75.3C (-103.54F) on the morning of Friday, March 20, as spotted by @TempGlobal on Twitter:
https://electroverse.net/antarctica-just-set-its-coldest-march-temperature/
Thanks to Bill Sellers for this link
The post Antarctica set its coldest EVER March temperature (-103.5F) appeared first on Ice Age Now.
via Ice Age Now
https://ift.tt/3andq1W
March 25, 2020 at 04:33PM


Half-buried factoids

It can be a quiz .
It can just be you showing off .
Or , of course , both @ @ @ @ @ but bonus points if any climate factoid is deemed interesting by 97 % of assembled @ @ @ @ @ please to DFHunter @ all – since all the pubs are closed can we have @ @ @ @ @ ?
found this site for a starter for 5 – https : //www.funtrivia.com/quizzes/ Since you @ @ @ @ @ s my humble reply to your suggestion .
A thread for climate-related trivia would be @ @ @ @ @ the every one of the crew and passengers of this boat must have a treasury @ @ @ @ @ not have a reason to be brought forth .
But that of course would be @ @ @ @ @ crew to arrange .
I am presently half-buried in factoids myself , but don ’ @ @ @ @ @ thread by quizzing you or other interested folk about them !

It can be a quiz. It can just be you showing off. Or, of course, both. Not limited to climate but bonus points if any climate factoid is deemed interesting by 97% of assembled Cliscep experts.
All complaints please to DFHunter
@all – since all the pubs are closed can we have a climate/general quizz night online? found this site for a starter for 5 – https://www.funtrivia.com/quizzes/
and Jit
@DFHunter Since you got Warnocked, here’s my humble reply to your suggestion. A thread for climate-related trivia would be of use I think because the every one of the crew and passengers of this boat must have a treasury of factoids that would otherwise not have a reason to be brought forth. But that of course would be up to one of the crew to arrange. I am presently half-buried in factoids myself, but don’t want to derail the thread by quizzing you or other interested folk about them!
Should be fun.


iowaclimatescienceeducation--2020-03-25--BBC Climate change: Green energy plant threat to wilderness areas

“ If we let these developments go ahead , the biodiversity will be gone long before climate change starts affecting it ” Wind , solar and hydro power installations pose a growing threat to key conservation areas , say researchers .
Researchers found that over 2,200 green energy plants have been built within the boundaries of the Earth ’ s remaining wilderness .
They say that around 17 % of renewable facilities globally are located in protected regions .
A further 900 plants are now being developed in key areas of biodiversity .
The amount of renewable energy facilities in @ @ @ @ @ @ @ over the last 20 years .
Green energy facilities are often much larger than fossil fuel power plants , with wind and solar needing areas of land up to 10 times greater than coal or gas to produce the same amount of energy .
The authors of the report say that greater care must be taken when planning and permitting renewable facilities .
“ If we let these developments go ahead , the biodiversity will be gone long before climate change starts affecting it , ” said Dr Allan .
“ We acknowledge @ @ @ @ @ @ @ will arm some sceptics , but anyone who reads the work will understand that we are not saying that renewables are bad , we just need to put them in the right places .
”

Guest essay by Eric Worrall
“If we let these developments go ahead, the biodiversity will be gone long before climate change starts affecting it”
Climate change: Green energy plant threat to wilderness areas
By Matt McGrathEnvironment correspondent
Wind, solar and hydro power installations pose a growing threat to key conservation areas, say researchers.
Researchers found that over 2,200 green energy plants have been built within the boundaries of the Earth’s remaining wilderness.
They say that around 17% of renewable facilities globally are located in protected regions.
A further 900 plants are now being developed in key areas of biodiversity.
The amount of renewable energy facilities in use around the world has essentially tripled over the last 20 years.
Green energy facilities are often much larger than fossil fuel power plants, with wind and solar needing areas of land up to 10 times greater than coal or gas to produce the same amount of energy.
…
The authors of the report say that greater care must be taken when planning and permitting renewable facilities.
“If we let these developments go ahead, the biodiversity will be gone long before climate change starts affecting it,” said Dr Allan.
“We acknowledge that there is a risk that we will arm some sceptics, but anyone who reads the work will understand that we are not saying that renewables are bad, we just need to put them in the right places.”
…


iowaclimatescienceeducation--2020-03-25--This is going to be shorter and faster than people think

Finally the world is tossing out the pointless old Influenza Pandemic plan that called for six months of slow bleeding .
Leaders are waking up to the high speed , hard and fast option .
Tonight 20 % of the worlds population are crushing that curve with a full lockdown because it ’ s the only option .
1.3 billion people in India are now in a three week home quarantine , joining France , Italy , China , Poland , Spain , Belgium , the United Kingdom , New York , California , South Africa , Colombia , Bolivia @ @ @ @ @ @ @ .
Sadly half a million people ( at least ) have caught Covid-19 and there will be another few doublings before the new lockdowns even start to show on the graphs .
The Lucky Country Downunder , meanwhile , is copying the Italian-plan-that-failed with a bunch of wishy arbitrary rules that change by the day and are not remotely enough .
We know the infection is spreading , but we ’ re still able to share our germs in Centerlink queues , at Kmart and while getting a haircut .
We can ’ @ @ @ @ @ @ @ , but we can have 600 at a school .
Borders are closed but people are still going through [ … ]

Option three gathers wings
Finally the world is tossing out the pointless old Influenza Pandemic plan that called for six months of slow bleeding. Leaders are waking up to the high speed, hard and fast option. Tonight 20% of the worlds population are crushing that curve with a full lockdown because it’s the only option. 1.3 billion people in India are now in a three week home quarantine, joining France, Italy, China, Poland, Spain, Belgium, the United Kingdom, New York, California, South Africa, Colombia, Bolivia, Jordan and Tunisia and New Zealand. Sadly half a million people (at least) have caught Covid-19 and there will be another few doublings before the new lockdowns even start to show on the graphs.
Maybe stop feeding it fresh meat?
The Lucky Country Downunder, meanwhile, is copying the Italian-plan-that-failed with a bunch of wishy arbitrary rules that change by the day and are not remotely enough. We know the infection is spreading, but we’re still able to share our germs in Centerlink queues, at Kmart and while getting a haircut. We can’t have 6 people at a wedding, but we can have 600 at a school. Borders are closed but people are still going through […]
Rating: 10.0/10 (1 vote cast)
via JoNova
https://ift.tt/3ajWwkJ
March 25, 2020 at 02:34PM


iowaclimatescienceeducation--2020-03-25--Trump might yet pull off a gamechanger thanks to chloroquine

If the trials of the anti-malarial chloroquine ( or variants ) work , Trump will get away with all the understatements he said in February .
On twitter the combination of Hydroxychloroquine and azithromycin are known as # TrumpPills .
The trials started yesterday .
As the death tolls mounts , the Democrats are surely planning to put all the Trump quotes like “ it ’ s going to disappear .
One day , it ’ s like a miracle ” on high rotation leading up to the election .
But if the trials of anti-viral agents bring good news @ @ @ @ @ @ @ if he was betting on that in February .
( Perhaps he was ? )
Though not many people spend two trillion dollars on a problem that ’ s disappearing .
Most patients treated with hydroxychloroquine alone cleared the virus in three to six days , compared to an average of 20 in China — … The authors advise : “ Use this treatment cocktail early , and don ’ t wait until a patient is on a ventilator in the intensive-care unit.
” They also note that in some places hydroxychloroquine is @ @ @ @ @ @ @ health workers in high exposure situations .

A High Stakes Game
If the trials of the anti-malarial chloroquine (or variants) work, Trump will get away with all the understatements he said in February. On twitter the combination of Hydroxychloroquine and azithromycin are known as #TrumpPills. The trials started yesterday.
As the death tolls mounts, the Democrats are surely planning to put all the Trump quotes like “it’s going to disappear. One day, it’s like a miracle” on high rotation leading up to the election. But if the trials of anti-viral agents bring good news, he can reframe the past as if he was betting on that in February. (Perhaps he was?)
Though not many people spend two trillion dollars on a problem that’s disappearing.
Combo of existing drugs shows promise against COVID-19
Most patients treated with hydroxychloroquine alone cleared the virus in three to six days, compared to an average of 20 in China — …
The authors advise: “Use this treatment cocktail early, and don’t wait until a patient is on a ventilator in the intensive-care unit.” They also note that in some places hydroxychloroquine is being used as a prophylactic treatment for health workers in high exposure situations.
Key […]
Rating: 0.0/10 (0 votes cast)
via JoNova
https://ift.tt/2QKxDai
March 25, 2020 at 02:12PM


Drought Factcheck

One of the frequent claims about global warming is that it will lead to more severe droughts .
For instance , the WMO were crystal clear in their latest Greenhouse Gas Bulletin : The last five years have been the hottest ever recorded .
The consequences are already making themselves felt in the form of more extreme weather events and associated disasters , from hurricanes to drought to floods to wildfires .
The Heartland Institute ’ s factcheck addresses this , with a particular focus on the US , for natural reasons as they are a US outfit .
• @ @ @ @ @ @ @ and less extreme drought events as the climate modestly warms .
• In 2017 and 2019 , the United States registered its smallest percentage of land area experiencing drought in recorded history .
• The United States is undergoing its longest period in recorded history with fewer than 40 percent of the country experiencing “ very dry ” conditions .
• The U.N. IPCC reports with “ high confidence ” that precipitation has increased over mid-latitude land areas of the Northern Hemisphere ( including the United States ) during the past 70 years @ @ @ @ @ @ @ ” about any negative trends globally .
( See https : //www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Chapter3_Low_Res.pdf , p .
191 . )
Short Summary : Real-world data show drought in the United States has become less frequent and severe as the climate has modestly warmed .
Moreover , the United Nations reports “ low confidence ” about any negative trends globally .
Droughts have always occurred , and they always will , so alarmists can not claim that any droughts are necessarily caused by global warming .
Instead , analysis of global and U.S. drought data show @ @ @ @ @ @ @ less frequent and severe than the droughts of the past several decades .
For example , the National Oceanic and Atmospheric Administration chart below shows that the United States is undergoing its longest period in recorded history without at least 40 percent of the country experiencing “ very dry ” conditions .
Note also the peaks in drought around 1978 , 1954 , 1930 , and 1900 are much larger than what the U.S. experienced in the 21st century and the late 20th century .
Figure 1 : Percentage of United States experiencing @ @ @ @ @ @ @ ) and “ very dry ” ( in yellow ) conditions .
Source : National Oceanic and Atmospheric Administration : https : //www.ncdc.noaa.gov/temp-and-precip/uspa/wet-dry/0 .
Picking up on the IPCC link , SR15 also stated : Regional variations can of course occur for all sorts of reasons , particularly multidecadal ocean cycles .
Overall though it is abundantly clear that the WMO ’ s claim has no scientific basis whatsoever .
The case of the US is particularly interesting though .
Just look again at the NOAA chart : Taking national rainfall trends can @ @ @ @ @ @ @ up regional variations .
However this tool measures the area of the country experiencing either extreme wet or extreme dry conditions .
NOAA define “ extreme ” as : Climate divisions with a standardized anomaly in the top ten percent ( > 90th percentile ) of their historical distribution are considered `` very warm/wet '' and those in the bottom ten percent ( < 10th percentile ) are classified as `` very cold/dry '' .
It is abundantly clear severe droughts have become much less common in the last two or three decades @ @ @ @ @ @ @ severe episodes stick out , including the 1910s and 1950s , in addition to the better known dustbowl years .
We can get a more exact picture from the regional precipitation trends : Generally speaking , most regions exhibit earlier periods of drought far more severe than anything seen in recent years .
The only real exception is the West , which shows little in the way of any trends at all .
( Contrary to wildly inaccurate claims about the recent Californian drought ) .
Interestingly though , earlier droughts don ’ @ @ @ @ @ @ @ in different regions .
For instance , the worst drought in the Northeast occurred in the 1960s , while by far the worst drought in the South was during the 1950s , a time often ignored but arguably as bad as the 1930s .
via NOT A LOT OF PEOPLE KNOW THAT

By Paul Homewood
One of the frequent claims about global warming is that it will lead to more severe droughts. For instance, the WMO were crystal clear in their latest Greenhouse Gas Bulletin:
The last five years have been the hottest ever recorded. The consequences are already making themselves felt in the form of more extreme weather events and associated disasters, from hurricanes to drought to floods to wildfires.
The Heartland Institute’s factcheck addresses this, with a particular focus on the US, for natural reasons as they are a US outfit.
Bullet-Point Summary:
The United States is benefiting from fewer and less extreme drought events as the climate modestly warms.
In 2017 and 2019, the United States registered its smallest percentage of land area experiencing drought in recorded history.
The United States is undergoing its longest period in recorded history with fewer than 40 percent of the country experiencing “very dry” conditions.
The U.N. IPCC reports with “high confidence” that precipitation has increased over mid-latitude land areas of the Northern Hemisphere (including the United States) during the past 70 years, while IPCC has “low confidence” about any negative trends globally. (See https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15_Chapter3_Low_Res.pdf, p. 191.)
Short Summary: Real-world data show drought in the United States has become less frequent and severe as the climate has modestly warmed. Moreover, the United Nations reports “low confidence” about any negative trends globally. Droughts have always occurred, and they always will, so alarmists cannot claim that any droughts are necessarily caused by global warming. Instead, analysis of global and U.S. drought data show the droughts that have occurred recently are less frequent and severe than the droughts of the past several decades.
For example, the National Oceanic and Atmospheric Administration chart below shows that the United States is undergoing its longest period in recorded history without at least 40 percent of the country experiencing “very dry” conditions. Note also the peaks in drought around 1978, 1954, 1930, and 1900 are much larger than what the U.S. experienced in the 21st century and the late 20th century.
Figure 1: U.S. Wet and Dry Extremes
Figure 1: Percentage of United States experiencing “very wet” (in green) and “very dry” (in yellow) conditions. Source: National Oceanic and Atmospheric
Administration: https://www.ncdc.noaa.gov/temp-and-precip/uspa/wet-dry/0.
https://climateataglance.com/climate-at-a-glance-drought/
Picking up on the IPCC link, SR15 also stated:
Regional variations can of course occur for all sorts of reasons, particularly multidecadal ocean cycles. Overall though it is abundantly clear that the WMO’s claim has no scientific basis whatsoever.
The case of the US is particularly interesting though. Just look again at the NOAA chart:
Taking national rainfall trends can be misleading, as they may cover up regional variations. However this tool measures the area of the country experiencing either extreme wet or extreme dry conditions. NOAA define “extreme” as:
Climate divisions with a standardized anomaly in the top ten percent (> 90th percentile) of their historical distribution are considered "very warm/wet" and those in the bottom ten percent (< 10th percentile) are classified as "very cold/dry".
It is abundantly clear severe droughts have become much less common in the last two or three decades, when measured this way.
Previous severe episodes stick out, including the 1910s and 1950s, in addition to the better known dustbowl years.
We can get a more exact picture from the regional precipitation trends:
https://www.ncdc.noaa.gov/cag/regional/time-series/101/pcp
Generally speaking, most regions exhibit earlier periods of drought far more severe than anything seen in recent years. The only real exception is the West, which shows little in the way of any trends at all. (Contrary to wildly inaccurate claims about the recent Californian drought).
Interestingly though, earlier droughts don’t always occur at the same time in different regions. For instance, the worst drought in the Northeast occurred in the 1960s, while by far the worst drought in the South was during the 1950s, a time often ignored but arguably as bad as the 1930s.
via NOT A LOT OF PEOPLE KNOW THAT
https://ift.tt/3brEDks
March 25, 2020 at 01:57PM


iowaclimatescienceeducation--2020-03-25--Fight Coronavirus with Global Warming

Fight Coronavirus with Global Warming

An important study of our experience with the covid19 pandemic shows that warmer , more humid weather works against transmission of the disease .
The paper is High Temperature and High Humidity Reduce the Transmission of COVID-19 by Jingyuan Wang , Ke Tang , Kai Feng and Weifeng Lv .
Excerpts in italics with my bolds .
Abstract : This paper investigates how air temperature and humidity influence the transmission of COVID-19 .
After estimating the serial interval of COVID-19 from 105 pairs of the virus carrier and the infected , we calculate the daily effective reproductive number , R @ @ @ @ @ @ @ cities with more than 40 cases .
Using the daily R values from January 21 to 23 , 2020 as proxies of non-intervened transmission intensity , we find , under a linear regression framework for 100 Chinese cities , high temperature and high relative humidity significantly reduce the transmission of COVID-19 , respectively , even after controlling for population density and GDP per capita of cities .
One degree Celsius increase in temperature and one percent increase in relative humidity lower R by 0.0383 and 0.0224 , respectively .
This result is consistent @ @ @ @ @ @ @ and high humidity significantly reduce the transmission of influenza .
It indicates that the arrival of summer and rainy season in the northern hemisphere can effectively reduce the transmission of the COVID-19 .
Discussion : Rough observations of outbreaks of COVID-19 outside China show a noteworthy phenomenon .
In the early dates of the outbreak , countries with relatively lower air temperature and lower humidity ( e.g .
Korea , Japan and Iran ) see severe outbreaks than warmer and more humid countries ( e.g .
Singapore , Malaysia and Thailand ) do @ @ @ @ @ @ @ average number of cases per day from February 8 to 29 as a rough measure of the severity of the COVID-19 outbreaks3 , in Figure 1 , we show that the severity is negatively related to temperature and relative humidity using 14 countries with more than 20 new cases during this period .
Inside China , the COVID-19 has spread widely to many cities , and the intensity of transmission and weather conditions in these cities vary largely ( shown in Table SI 1 ) , we can , therefore , analyze the @ @ @ @ @ @ @ weather factors .
In order to formally quantify the transmission of COVID-19 , we first fit 105 samples of serial intervals with the Weibull distribution ( a distribution commonly used to fit the serial interval of influenza [ 8 ] ) , then calculate the effective reproductive number , R , a quantity measuring the severity of infectiousness [ 9 ] , for each of all 100 Chinese cities with more than 40 cases .
Figure 2 shows the average R values from January 21 to 23 for different Chinese cities geographically .
@ @ @ @ @ @ @ , cities in the northern area of China show relatively larger R values and lower temperatures and relative humidity .
The scatter plots in Figure 3 illustrate two negative relations between the daily air temperature and R value and between the daily relative humidity and R value , respectively .
Our finding is consistent with the evidence that high temperature and high humidity reduce the transmission of influenza [ 10-14 ] , which can be explained by two possible reasons : First , the influenza virus is more stable in cold temperature , @ @ @ @ @ @ @ viruses , remain airborne longer in dry air [ 15 , 16 ] .
Second , cold and dry weather can also weaken the hosts ’ immunity and make them more susceptible to the virus [ 17 , 18 ] .
These mechanisms are also likely to apply to the COVID-19 transmission .
Our result is also consistent with the evidence that high temperature and high relative humidity reduce the viability of SARS coronavirus [ 19,20 ] .
If omitting control variables , 7 the fixed-effects model of Table 2 provides an estimation @ @ @ @ @ @ @ city given its temperature and relative humidity : Assuming that the same relationship of Equation ( 1 ) applies to cities outside China and that the temperature and relative humid of 2020 are the same as those in 2019 , we can draw a map of R values for worldwide cities in Figure 4 by plugging the average March and July temperatures and relative humidity of 2019 into Equation ( 1 ) .
This figure cautions people of the risk of COVID-19 outbreak worldwide , in March and July of 2020 , respectively @ @ @ @ @ @ @ are larger for temperate countries and smaller for tropical countries in March .
In July , the arrival of summer and rainy season in the northern hemisphere can effectively reduce the transmission of the COVID-19 ; however , risks remain in some countries in the southern hemisphere ( e.g .
Australia and South Africa ) .
If we plug the normal summer temperature and relative humidity of Tokyo ( 28oC and 85 % , respectively ) into Equation ( 1 ) , the transmission of the COVID19 in Tokyo will be seriously reduced @ @ @ @ @ @ @ estimated R value decreases from 1.914 to 0.992 , a 48 % drop !

An important study of our experience with the covid19 pandemic shows that warmer, more humid weather works against transmission of the disease. The paper is High Temperature and High Humidity Reduce the Transmission of COVID-19 by Jingyuan Wang, Ke Tang, Kai Feng and Weifeng Lv. Excerpts in italics with my bolds.
Abstract: This paper investigates how air temperature and humidity influence the transmission of COVID-19. After estimating the serial interval of COVID-19 from 105 pairs of the virus carrier and the infected, we calculate the daily effective reproductive number, R, for each of all 100 Chinese cities with more than 40 cases. Using the daily R values from January 21 to 23, 2020 as proxies of non-intervened transmission intensity, we find, under a linear regression framework for 100 Chinese cities, high temperature and high relative humidity significantly reduce the transmission of COVID-19, respectively, even after controlling for population density and GDP per capita of cities. One degree Celsius increase in temperature and one percent increase in relative humidity lower R by 0.0383 and 0.0224, respectively. This result is consistent with the fact that the high temperature and high humidity significantly reduce the transmission of influenza. It indicates that the arrival of summer and rainy season in the northern hemisphere can effectively reduce the transmission of the COVID-19.
Discussion: Rough observations of outbreaks of COVID-19 outside China show a noteworthy phenomenon. In the early dates of the outbreak, countries with relatively lower air temperature and lower humidity (e.g. Korea, Japan and Iran) see severe outbreaks than warmer and more humid countries (e.g. Singapore, Malaysia and Thailand) do. Considering the natural log of the average number of cases per day from February 8 to 29 as a rough measure of the severity of the COVID-19 outbreaks3 , in Figure 1, we show that the severity is negatively related to temperature and relative humidity using 14 countries with more than 20 new cases during this period.
Inside China, the COVID-19 has spread widely to many cities, and the intensity of transmission and weather conditions in these cities vary largely (shown in Table SI 1), we can, therefore, analyze the determinants of COVID-19 transmission, especially the weather factors. In order to formally quantify the transmission of COVID-19, we first fit 105 samples of serial intervals with the Weibull distribution (a distribution commonly used to fit the serial interval of influenza[8]), then calculate the effective reproductive number, R, a quantity measuring the severity of infectiousness[9] , for each of all 100 Chinese cities with more than 40 cases.
Figure 2 shows the average R values from January 21 to 23 for different Chinese cities geographically. Compared with the southeast coast of China, cities in the northern area of China show relatively larger R values and lower temperatures and relative humidity. The scatter plots in Figure 3 illustrate two negative relations between the daily air temperature and R value and between the daily relative humidity and R value, respectively.
Our finding is consistent with the evidence that high temperature and high humidity reduce the transmission of influenza[10-14] , which can be explained by two possible reasons: First, the influenza virus is more stable in cold temperature, and respiratory droplets, as containers of viruses, remain airborne longer in dry air[15, 16] . Second, cold and dry weather can also weaken the hosts’ immunity and make them more susceptible to the virus[17, 18] . These mechanisms are also likely to apply to the COVID-19 transmission. Our result is also consistent with the evidence that high temperature and high relative humidity reduce the viability of SARS coronavirus[19,20] .
If omitting control variables, 7 the fixed-effects model of Table 2 provides an estimation of the R value for a certain city given its temperature and relative humidity: Assuming that the same relationship of Equation (1) applies to cities outside China and that the temperature and relative humid of 2020 are the same as those in 2019, we can draw a map of R values for worldwide cities in Figure 4 by plugging the average March and July temperatures and relative humidity of 2019 into Equation (1). This figure cautions people of the risk of COVID-19 outbreak worldwide, in March and July of 2020, respectively. As expected, the R values are larger for temperate countries and smaller for tropical countries in March. In July, the arrival of summer and rainy season in the northern hemisphere can effectively reduce the transmission of the COVID-19; however, risks remain in some countries in the southern hemisphere (e.g. Australia and South Africa). If we plug the normal summer temperature and relative humidity of Tokyo (28oC and 85%, respectively) into Equation (1), the transmission of the COVID19 in Tokyo will be seriously reduced between March and the Olympics: the estimated R value decreases from 1.914 to 0.992, a 48% drop!
via Science Matters
https://ift.tt/39fDFGh
March 25, 2020 at 12:46PM


iowaclimatescienceeducation--2020-03-25--COVID-19: Updated data implies that UK modelling hugely overestimates the expected death rates from

COVID-19: Updated data implies that UK modelling hugely overestimates the expected death rates from infection

There has been much media coverage about the danger to life posed by the COVID-19 coronavirus pandemic .
While it is clearly a serious threat , one should consider whether the best evidence supports the current degree of panic and hence government policy .
Much of the concern in the UK resulted from a non-peer reviewed study published by the COVID-19 Response Team from Imperial College ( Ferguson et al 2020 [ 1 ] ) .
In this article , I examine whether data from the Diamond Princess cruise ship – arguably the most useful data set available – support @ @ @ @ @ @ @ study .
I find that it does not do so .
The likely fatality rates for age groups from 60 upwards , which account for the vast bulk of projected deaths , appear to be much lower than those in the Ferguson et al .
study .
Metrics for COVID-19 ’ s fatality rate and their estimation The fatality rate from infection ( IFR ) , by age group , is a key parameter in determining how serious a threat the COVID-19 pandemic represents .
Unfortunately , the IFR is difficult to determine @ @ @ @ @ @ @ the fatality rate for cases where the COVID-19 virus can be shown , by a standard test , to be present , whether or not there are any symptoms .
This is referred to as the true case fatality rate ( tCFR ) .
The tCFR will overestimate the IFR , since a proportion of people who actually have been infected may show no viral presence when tested , either because they have already fought off and cleared an infection without any noticeable symptoms , or perhaps because they have pre-existing immunity .
@ @ @ @ @ @ @ to a sample of people without regard to whether they show symptoms , the tCFR may provide a reasonable , albeit somewhat biased high , estimate of the IFR .
However , determining tCFR is not simple either , since in most cases infected people with no or mild symptoms will not be tested for COVID-19 .
Attempts have nevertheless been made to estimate tCFR by adjusting estimates of the CFR based on symptomatic cases only ( sCFR ) , by adjusting for the non-random nature of testing , and also for the @ @ @ @ @ @ @ being known for some time .
The Ferguson et al .
study used estimates of the IFR [ 2 ] from another paper from the same team , Verity et al .
( 2020 ) [ 3 ] , which had been published a few days earlier on 13 March .
Very helpfully , Verity et al.
, unlike Ferguson et al.
, published the computer code and data that they used .
The Verity et al .
CFR estimates were derived primarily from Chinese data , which reflected non-random testing .
The @ @ @ @ @ @ @ reality , tCFR estimates ) by adjusting their CFR estimates using infection prevalence data for expatriates evacuated from Wuhan , all of whom were tested for COVID-19 infection .
This approach involves very large uncertainties .
An alternative approach to estimating the tCFR , as a proxy for the IFR , is to use data from a large sample of people , all of whom were tested for the presence of the virus without regard to whether they showed any symptoms , with all who tested positive subsequently being isolated and the case @ @ @ @ @ @ @ .
While the sample of expatriates evacuated from Wuhan is too small for this purpose , [ 4 ] occupants of the Diamond Princess cruise ship do provide a suitable such sample .
[ 5 ] Moreover , the Diamond Princess sample has the advantage that it consists mainly of people from high income countries , and those requiring hospitalisation were treated in such countries .
The Diamond Princess sample may well represent the best available evidence regarding tCFR for older age groups , who are most at risk .
Verity et al @ @ @ @ @ @ @ the Diamond Princess , but did not use sCFR or tCFR estimates from them for their main CFR and IFR estimates .
[ 6 ] When Verity et al .
was prepared , the final death toll was not known .
The data available only ran to 5 March 2020 , at which point 7 passengers had died .
The authors therefore used a fitted probability distribution for the delay from testing positive to dying to estimate that those deaths would represent 56 % of the eventual death toll .
They accordingly therefore @ @ @ @ @ @ @ of 12.5 deaths .
Here , I adopt the same death rate model and use the same data set , but brought up to date .
By 21 March the number of deaths had barely changed , increasing from 7 to 8 .
Of those 8 deaths , 3 are reported to have been in their 70s and 4 in their 80s .
I allocate the remaining , unknown age , person pro rata between those two age groups .
As at 21 March the Verity et al .
model estimates that 96 @ @ @ @ @ @ @ occurred , so we can scale up to 100 % , giving an estimated ultimate death toll of 8.34 , allocated as to 3.58 to the 70-79 age group and 4.77 to the 80+ age group .
Accordingly , the Verity et al central estimate for the Diamond Princess death toll , of 12.5 eventual deaths , is 50 % too high .
This necessarily means that the estimates of tCFR and sCFR they derived from it are too high by the same proportion .
The Diamond Princess dataset was published by the @ @ @ @ @ @ @ NIID ) .
I use the second version published on 21 February [ 7 ] , which gives detailed data for 619 confirmed cases , updating it for subsequent test results .
[ 8 ] Verity used the original 19 February version of NIID , which gave data for 531 confirmed cases , although they did update it for subsequent test results .
The entire set of passengers and crew , totalling 3711 individuals , was tested for COVID-19 .
Some 706 ( 19.0 % ) ultimately had positive test results , of @ @ @ @ @ @ @ for 619 of them ) 51 % were asymptomatic .
The infection rate varied between 10.0 % for ages under 30 years to 24.5 % for ages 60+ years .
The age-distribution was only known for cases included in the NIID data .
Verity et al .
assumed that the age distribution for the overall total of 706 confirmed cases was the same as for the 531 NIID reported cases that they used .
I do the same , but using the later NIID data , with 619 reported cases .
On that @ @ @ @ @ @ @ people in respectively the 60–69 , 70–79 and 80+ key age groups had positive test results .
Recall that tCFR is the eventual death toll divided by the total numbers testing positive .
My overall tCFR central estimates from the Diamond Princess 70+ age groups , where all the deaths are taken to have occurred , are 2.54 % overall ( 8.34/328.5 ) , [ 9 ] with a breakdown of 1.34 % for ages 70-79 ( 3.58/266.9 ) and 8.04 % ( 4.77/61.6 ) for ages 80+ .
For the 60–69 age @ @ @ @ @ @ @ to make a crude median estimate of the tCFR , by calculating what it would need to be for there to be a 50 % probability that no 60-69 year-old has died , as appears to have been the case .
The thus-implied tCFR is 0.34 % .
There were too few Diamond Princess occupants in age groups below 60 with positive test results to provide any useful information about the COVID-19 tCFR for those groups .
It appears that in about 30 % of symptomatic cases the standard RT-PCR test for COVID-19 @ @ @ @ @ @ @ patient is in fact infected .
[ 10 ] There is no evidence of any COVID-19 related deaths among Diamond Princess occupants who tested negative , which would be consistent with a lower viral load being associated with a lower probability both of a positive RT-PCR test result and of eventual death .
The false-negative rate may be slightly lower for Diamond Princess occupants , a few of whom may have been retested or tested by a more reliable method where they had typical COVID-19 symptoms but an initially negative RT-PCR test result @ @ @ @ @ @ @ the proportion of asymptomatic infected cases that are not detected by a RT-PCR test will be somewhat higher than the 30 % estimated for symptomatic cases .
We accordingly adjust all the tCFR ratios estimated from Diamond Princess case data down by 30 % on account of false-negative test results .
The observed deaths of Diamond Princess occupants occurred over a 45 day period , during which a non-negligible percentage of old people would be expected to die from non-COVID-19 related causes .
I have accordingly deducted from the adjusted tCFR ratios an @ @ @ @ @ @ @ groups , based on UK age-stratified 2018 death rates , [ 11 ] to arrive at estimates of deaths caused by COVID-19 .
There are arguments for the non-COVID death rates being either higher or lower than those for the UK population of the same age , but using those death statistics appears to be a reasonable first approximation .
Comparing the Ferguson et al .
UK and Diamond Princess based fatality rate estimates The results of the foregoing analysis are set out in Table 1 .
The key finding is that the @ @ @ @ @ @ @ groups , which must if anything overestimate their IFRs , are far lower than the corresponding IFR estimates used by Ferguson et al .
in the study adopted by the UK government .
[ 12 ] Those age groups account for the vast bulk of projected deaths .
For people aged 60–69 , the Ferguson et al IFR estimate is 19.4 times as high as the best tCFR estimate based on Diamond Princess data , for the 70–79 age group it is 8.3 times as high , and for the 80+ age group @ @ @ @ @ @ @ Table 1 : True Case Fatality Rates estimated from the latest Diamond Princess data compared with Infection Fatality Rates per Ferguson et al .
2019 , used by the UK government Note : An all-causes tCFR of 0.34 % ( and hence 0.69 notional ultimate fatalities ) is assumed for age-group 60-69 despite there being no actual fatalities in that age group ( see text ) .
Expected non-COVID-19 fatalities are based on UK 2018 death rates by age group applied to the DP positive test cases , scaled by the 45 day @ @ @ @ @ @ @ and divided by the same 0.96 factor used to scale up the 8 actual deaths .
DP= Diamond Princess .
Based on the Diamond Princess data , the COVID-19 fatality rates by age-group assumed by Ferguson et al .
appear to be far too pessimistic for all 60+ age groups , where the vast bulk of fatalities are projected to occur .
It is quite possible that they are also too pessimistic for younger age groups as well , but unfortunately the Diamond Princess data are uninformative about death rates below age 60 @ @ @ @ @ @ @ the 60+ age groups the projected excess death rates , based on Diamond Princess case data , caused by COVID-19 is substantially lower than the underlying non-COVID-19 annual death rate .
Even assuming , very pessimistically , that there is no overlap between the two , and that the same proportion of each age group becomes infected , projected COVID-19 related deaths from an epidemic in which the vast bulk of the population became infected with COVID-19 are only 9 % of expected annual non-COVID deaths for the 60–69 age group .
[ @ @ @ @ @ @ @ , the proportion is 20 % , and for the 80+ age group it is 26 % .
Relative to the expected non-COVID deaths over two years , the approximate period during which very onerous restrictions are projected to be in force in the UK , these COVID-19 excess death proportions would each be reduced by almost half .
In practice , a high proportion of people killed by COVID-19 will have serious underlying health conditions , and would be much more likely than average to die from non-COVID-19 causes .
[ 1 @ @ @ @ @ @ @ non-pharmaceutical interventions ( NPIs ) to reduce COVID-19 mortality and healthcare demand , Imperial College COVID-19 Response Team Report 9 , 16 March 2020 , https : //spiral.imperial.ac.uk:8443/handle/10044/1/77482 [ 2 ] Ferguson et al .
adjusted the Verity et al .
IFR estimates “ to account for a non-uniform attack rate ” , without giving further information about the assumed attack rates .
They appear to have increased the Verity et al .
IFR estimates for all 60+ age groups by approximately 19 % , while making little or no changes to those @ @ @ @ @ @ @ unclear whether doing so was justified .
[ 3 ] Verity R , Okell LC , Dorigatti I , et al .
Estimates of the severity of COVID-19 disease .
medRxiv 13 March 2020 ; https : //www.medrxiv.org/content/10.1101/2020.03.09.20033357v1 .
[ 4 ] Their sample of evacuated expatriates is 689 people , of whom on 6 tested positive for COVID-19 , none of whom died .
[ 5 ] Russell et al.
, “ Estimating the infection and case fatality ratio for COVID-19 using age-adjusted data from the outbreak on the Diamond Princess cruise @ @ @ @ @ @ @ March 2020 , did use exclusively Diamond Princess data .
However , the early data that they used was incomplete and their IFR ( actually tCFR ) estimates appear to be based on assuming 26 eventual deaths , and hence are far too high .
[ 6 ] Verity et al .
simply noted that that figures derived from the Diamond Princess data set were “ consistent ” with their main estimates , meaning that they fell within their very wide main estimate uncertainty ranges .
[ 8 ] Using the same sources @ @ @ @ @ @ @ for dates from 20 February on .
Doing so yields a total of 704 positive test results , which I adjust to equal the cumulative total of 706 results stated in the final , 2 March 2020 , update .
[ 9 ] A simple estimate based on the binomial distribution suggests that the 97.5 % upper uncertainty bound is approximately double this figure .
[ 12 ] Moreover , I am unable to reproduce the Ferguson et al .
estimate of 510,000 deaths in the ‘ Do nothing ’ case , based @ @ @ @ @ @ @ the population being infected and using their IFRs .
Note that the Ferguson et al .
IFR estimates assume that , as was the case for the infected Diamond Princess occupants , health systems have not been overwhelmed by COVID-19 cases .
[ 13 ] Based on the Ferguson et al .
assumption that 81 % of the population eventually becomes infected .

By Nic Lewis
Introduction
There has been much media coverage about the danger to life posed by the COVID-19 coronavirus pandemic. While it is clearly a serious threat, one should consider whether the best evidence supports the current degree of panic and hence government policy. Much of the concern in the UK resulted from a non-peer reviewed study published by the COVID-19 Response Team from Imperial College (Ferguson et al 2020[1]). In this article, I examine whether data from the Diamond Princess cruise ship – arguably the most useful data set available – support the fatality rate assumptions underlying the Imperial study. I find that it does not do so. The likely fatality rates for age groups from 60 upwards, which account for the vast bulk of projected deaths, appear to be much lower than those in the Ferguson et al. study.
Metrics for COVID-19’s fatality rate and their estimation
The fatality rate from infection (IFR), by age group, is a key parameter in determining how serious a threat the COVID-19 pandemic represents. Unfortunately, the IFR is difficult to determine. It is more practical to estimate the fatality rate for cases where the COVID-19 virus can be shown, by a standard test, to be present, whether or not there are any symptoms. This is referred to as the true case fatality rate (tCFR). The tCFR will overestimate the IFR, since a proportion of people who actually have been infected may show no viral presence when tested, either because they have already fought off and cleared an infection without any noticeable symptoms, or perhaps because they have pre-existing immunity. Nevertheless, where testing has been applied to a sample of people without regard to whether they show symptoms, the tCFR may provide a reasonable, albeit somewhat biased high, estimate of the IFR.
However, determining tCFR is not simple either, since in most cases infected people with no or mild symptoms will not be tested for COVID-19. Attempts have nevertheless been made to estimate tCFR by adjusting estimates of the CFR based on symptomatic cases only (sCFR), by adjusting for the non-random nature of testing, and also for the outcome of positive test result cases not being known for some time.
The Imperial studies
The Ferguson et al. study used estimates of the IFR[2] from another paper from the same team, Verity et al. (2020)[3], which had been published a few days earlier on 13 March. Very helpfully, Verity et al., unlike Ferguson et al., published the computer code and data that they used.
The Verity et al. CFR estimates were derived primarily from Chinese data, which reflected non-random testing. The authors obtained age-stratified IFR estimates (in reality, tCFR estimates) by adjusting their CFR estimates using infection prevalence data for expatriates evacuated from Wuhan, all of whom were tested for COVID-19 infection. This approach involves very large uncertainties.
An alternative approach to estimating the tCFR, as a proxy for the IFR, is to use data from a large sample of people, all of whom were tested for the presence of the virus without regard to whether they showed any symptoms, with all who tested positive subsequently being isolated and the case outcome recorded. I use that approach. While the sample of expatriates evacuated from Wuhan is too small for this purpose,[4] occupants of the Diamond Princess cruise ship do provide a suitable such sample.[5] Moreover, the Diamond Princess sample has the advantage that it consists mainly of people from high income countries, and those requiring hospitalisation were treated in such countries.
The Diamond Princess sample may well represent the best available evidence regarding tCFR for older age groups, who are most at risk. Verity et al (2020) did analyse data from the Diamond Princess, but did not use sCFR or tCFR estimates from them for their main CFR and IFR estimates.[6]
The Diamond Princess death toll
When Verity et al. was prepared, the final death toll was not known. The data available only ran to 5 March 2020, at which point 7 passengers had died. The authors therefore used a fitted probability distribution for the delay from testing positive to dying to estimate that those deaths would represent 56% of the eventual death toll. They accordingly therefore estimated the tCFR using a scaled figure of 12.5 deaths.
Here, I adopt the same death rate model and use the same data set, but brought up to date. By 21 March the number of deaths had barely changed, increasing from 7 to 8. Of those 8 deaths, 3 are reported to have been in their 70s and 4 in their 80s. I allocate the remaining, unknown age, person pro rata between those two age groups. As at 21 March the Verity et al. model estimates that 96% of the eventual deaths should have occurred, so we can scale up to 100%, giving an estimated ultimate death toll of 8.34, allocated as to 3.58 to the 70-79 age group and 4.77 to the 80+ age group.
Accordingly, the Verity et al central estimate for the Diamond Princess death toll, of 12.5 eventual deaths, is 50% too high. This necessarily means that the estimates of tCFR and sCFR they derived from it are too high by the same proportion.
Numbers testing positive
The Diamond Princess dataset was published by the Japan National Institute of Infectious Diseases (NIID). I use the second version published on 21 February[7], which gives detailed data for 619 confirmed cases, updating it for subsequent test results.[8] Verity used the original 19 February version of NIID, which gave data for 531 confirmed cases, although they did update it for subsequent test results.
The entire set of passengers and crew, totalling 3711 individuals, was tested for COVID-19. Some 706 (19.0%) ultimately had positive test results, of whom (based on the NIID data for 619 of them) 51% were asymptomatic. The infection rate varied between 10.0% for ages under 30 years to 24.5% for ages 60+ years. The age-distribution was only known for cases included in the NIID data. Verity et al. assumed that the age distribution for the overall total of 706 confirmed cases was the same as for the 531 NIID reported cases that they used. I do the same, but using the later NIID data, with 619 reported cases. On that basis, 201.9, 266.9 and 61.6 people in respectively the 60–69, 70–79 and 80+ key age groups had positive test results.
tCFR estimate
Recall that tCFR is the eventual death toll divided by the total numbers testing positive.
My overall tCFR central estimates from the Diamond Princess 70+ age groups, where all the deaths are taken to have occurred, are 2.54% overall (8.34/328.5),[9] with a breakdown of 1.34% for ages 70-79 (3.58/266.9) and 8.04% (4.77/61.6) for ages 80+. For the 60–69 age group, there are sufficient test-positive occupants to make a crude median estimate of the tCFR, by calculating what it would need to be for there to be a 50% probability that no 60-69 year-old has died, as appears to have been the case. The thus-implied tCFR is 0.34%. There were too few Diamond Princess occupants in age groups below 60 with positive test results to provide any useful information about the COVID-19 tCFR for those groups.
Adjustments for false negatives and underlying death rates
It appears that in about 30% of symptomatic cases the standard RT-PCR test for COVID-19 infection gives a negative result when the patient is in fact infected.[10] There is no evidence of any COVID-19 related deaths among Diamond Princess occupants who tested negative, which would be consistent with a lower viral load being associated with a lower probability both of a positive RT-PCR test result and of eventual death. The false-negative rate may be slightly lower for Diamond Princess occupants, a few of whom may have been retested or tested by a more reliable method where they had typical COVID-19 symptoms but an initially negative RT-PCR test result. However, it seems likely that the proportion of asymptomatic infected cases that are not detected by a RT-PCR test will be somewhat higher than the 30% estimated for symptomatic cases. We accordingly adjust all the tCFR ratios estimated from Diamond Princess case data down by 30% on account of false-negative test results.
The observed deaths of Diamond Princess occupants occurred over a 45 day period, during which a non-negligible percentage of old people would be expected to die from non-COVID-19 related causes. I have accordingly deducted from the adjusted tCFR ratios an allowance for non-COVID-19 deaths for 70+ age groups, based on UK age-stratified 2018 death rates,[11] to arrive at estimates of deaths caused by COVID-19. There are arguments for the non-COVID death rates being either higher or lower than those for the UK population of the same age, but using those death statistics appears to be a reasonable first approximation.
Comparing the Ferguson et al. UK and Diamond Princess based fatality rate estimates
The results of the foregoing analysis are set out in Table 1. The key finding is that the estimated tCFRs for Diamond Princess 60+ age groups, which must if anything overestimate their IFRs, are far lower than the corresponding IFR estimates used by Ferguson et al. in the study adopted by the UK government.[12] Those age groups account for the vast bulk of projected deaths. For people aged 60–69, the Ferguson et al IFR estimate is 19.4 times as high as the best tCFR estimate based on Diamond Princess data, for the 70–79 age group it is 8.3 times as high, and for the 80+ age group it is 2.1 times as high.
Table 1: True Case Fatality Rates estimated from the latest Diamond Princess data compared with Infection Fatality Rates per Ferguson et al. 2019, used by the UK government
Note: An all-causes tCFR of 0.34% (and hence 0.69 notional ultimate fatalities) is assumed for age-group 60-69 despite there being no actual fatalities in that age group (see text). Expected non-COVID-19 fatalities are based on UK 2018 death rates by age group applied to the DP positive test cases, scaled by the 45 day period over which COVID-19 deaths were recorded and divided by the same 0.96 factor used to scale up the 8 actual deaths. DP= Diamond Princess.
Discussion
Based on the Diamond Princess data, the COVID-19 fatality rates by age-group assumed by Ferguson et al. appear to be far too pessimistic for all 60+ age groups, where the vast bulk of fatalities are projected to occur. It is quite possible that they are also too pessimistic for younger age groups as well, but unfortunately the Diamond Princess data are uninformative about death rates below age 60.
It is notable that for all the 60+ age groups the projected excess death rates, based on Diamond Princess case data, caused by COVID-19 is substantially lower than the underlying non-COVID-19 annual death rate. Even assuming, very pessimistically, that there is no overlap between the two, and that the same proportion of each age group becomes infected, projected COVID-19 related deaths from an epidemic in which the vast bulk of the population became infected with COVID-19 are only 9% of expected annual non-COVID deaths for the 60–69 age group.[13] For the 70–79 age group, the proportion is 20%, and for the 80+ age group it is 26%. Relative to the expected non-COVID deaths over two years, the approximate period during which very onerous restrictions are projected to be in force in the UK, these COVID-19 excess death proportions would each be reduced by almost half. In practice, a high proportion of people killed by COVID-19 will have serious underlying health conditions, and would be much more likely than average to die from non-COVID-19 causes.
Nicholas Lewis 25 March 2020
Originally posted here
[1] Neil M Ferguson, Impact of non-pharmaceutical interventions (NPIs) to reduce COVID-19 mortality and healthcare demand, Imperial College COVID-19 Response Team Report 9, 16 March 2020, https://spiral.imperial.ac.uk:8443/handle/10044/1/77482
[2] Ferguson et al. adjusted the Verity et al. IFR estimates “to account for a non-uniform attack rate”, without giving further information about the assumed attack rates. They appear to have increased the Verity et al. IFR estimates for all 60+ age groups by approximately 19%, while making little or no changes to those for younger age groups. It is unclear whether doing so was justified.
[3] Verity R, Okell LC, Dorigatti I, et al. Estimates of the severity of COVID-19 disease. medRxiv 13 March 2020; https://www.medrxiv.org/content/10.1101/2020.03.09.20033357v1.
[4] Their sample of evacuated expatriates is 689 people, of whom on 6 tested positive for COVID-19, none of whom died.
[5]Russell et al., “Estimating the infection and case fatality ratio for COVID-19 using age-adjusted data from the outbreak on the Diamond Princess cruise ship”, medRxiv preprint dated 9 March 2020, did use exclusively Diamond Princess data. However, the early data that they used was incomplete and their IFR (actually tCFR) estimates appear to be based on assuming 26 eventual deaths, and hence are far too high.
[6] Verity et al. simply noted that that figures derived from the Diamond Princess data set were “consistent” with their main estimates, meaning that they fell within their very wide main estimate uncertainty ranges.
[7] Field Briefing: Diamond Princess COVID-19 Cases, 20 Feb Update. National Institute of Infectious Diseases, Japan https://www.niid.go.jp/niid/en/2019-ncov-e/9417-covid-dp-fe-02.html
[8] Using the same sources as given in Verity et al., for dates from 20 February on. Doing so yields a total of 704 positive test results, which I adjust to equal the cumulative total of 706 results stated in the final, 2 March 2020, update.
[9] A simple estimate based on the binomial distribution suggests that the 97.5% upper uncertainty bound is approximately double this figure.
[10] https://www.sciencedaily.com/releases/2020/02/200226151951.htm
[11] https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/deaths/datasets/deathregistrationssummarytablesenglandandwalesdeathsbysingleyearofagetables and https://www.ons.gov.uk/file?uri=%2fpeoplepopulationandcommunity%2fpopulationandmigration%2fpopulationestimates%2fdatasets%2fpopulationestimatesforukenglandandwalesscotlandandnorthernireland%2fmid20182019laboundaries/ukmidyearestimates20182018ladcodes.xls
[12] Moreover, I am unable to reproduce the Ferguson et al. estimate of 510,000 deaths in the ‘Do nothing’ case, based on their estimate of 81% of the population being infected and using their IFRs. Note that the Ferguson et al. IFR estimates assume that, as was the case for the infected Diamond Princess occupants, health systems have not been overwhelmed by COVID-19 cases.
[13] Based on the Ferguson et al. assumption that 81% of the population eventually becomes infected.
via Climate Etc.
https://ift.tt/2UAnUo5
March 25, 2020 at 12:20PM


iowaclimatescienceeducation--2020-03-25--Astronaut Christina Koch Services a 3-D Biological Printer

In this image from Dec. 2019 , astronaut Christina Koch handles media bags that enable the manufacturing of organ-like tissues @ @ @ @ @ BFF ) , a 3-D biological printer on the International Space Station .
The BFF @ @ @ @ @ a larger system capable of manufacturing whole , fully functioning human organs from existing patient @ @ @ @ @ more about science experiments aboard the station and how it helps improve life on Earth @

From NASA
In this image from Dec. 2019, astronaut Christina Koch handles media bags that enable the manufacturing of organ-like tissues using the BioFabrication Facility (BFF), a 3-D biological printer on the International Space Station. The BFF could become a part of a larger system capable of manufacturing whole, fully functioning human organs from existing patient cells in microgravity.
Learn more about science experiments aboard the station and how it helps improve life on Earth.
Video: Science at 17,500 Miles Per Hour
Image Credit: NASA
Last Updated: March 24, 2020
Editor: Yvette Smith