Repeated predictions that vector-borne disease prevalence will increase with 
global warming are usually based on univariate models. To accommodate the full 
range of constraints, the present-day distribution of tick-borne encephalitis 
virus (TBEv) was matched statistically to current climatic variables, to provide 
a multivariate description of present-day areas of disease risk. This was then 
applied to outputs of a general circulation model that predicts how climatic 
variables may change in the future, and future distributions of TBEv were 
predicted for them. The expected summer rise in temperature and decrease in 
moisture appears to drive the distribution of TBEv into higher-latitude and 
higher-altitude regions progressively through the 2020s, 2050s and 2080s. The 
final toe-hold in the 2080s may be confined to a small part of Scandinavia, 
including new foci in southern Finland. The reason for this apparent contraction 
of the range of TBEv is that its transmission cycles depend on a particular 
pattern of tick seasonal dynamics, which may be disrupted by climate change. The 
observed marked increase in incidence of tick-borne encephalitis in most parts 
of Europe since 1993 may be due to non-biological causes, such as political and 
sociological changes.