Drought and immunity determine the intensity of West Nile virus epidemics and climate change impacts.

The effect of global climate change on infectious disease remains hotly debated because multiple extrinsic and intrinsic drivers interact to influence transmission dynamics in nonlinear ways. The dominant drivers of widespread pathogens, like West Nile virus, can be challenging to identify due to regional variability in vector and host ecology, with past studies producing disparate findings. Here, we used analyses at national and state scales to examine a suite of climatic and intrinsic drivers of continental-scale West Nile virus epidemics, including an empirically derived mechanistic relationship between temperature and transmission potential that accounts for spatial variability in vectors.

Response of snow-dependent hydrologic extremes to continued global warming.

Snow accumulation is critical for water availability in the northern hemisphere , raising concern that global warming could have important impacts on natural and human systems in snow-dependent regions . Although regional hydrologic changes have been observed (e.g.

Transient regional climate change: analysis of the summer climate response in a high-resolution, century-scale, ensemble experiment over the continental United States.

Integrating the potential for climate change impacts into policy and planning decisions requires quantification of the emergence of sub-regional climate changes that could occur in response to transient changes in global radiative forcing. Here we report results from a high-resolution, century-scale, ensemble simulation of climate in the United States, forced by atmospheric constituent concentrations from the Special Report on Emissions Scenarios (SRES) A1B scenario. We find that 21 century summer warming permanently emerges beyond the baseline decadal-scale variability prior to 2020 over most areas of the continental U.