This report is an authoritative assessment of the science of climate change, with a focus on the United States. It represents the second of two volumes of the Fourth National Climate Assessment, mandated by the Global Change Research Act of 1990.| nca2018.globalchange.gov
Climatic conditions across the U.S. farm belt are triggering a rise in global food prices that threatens to fuel political unrest in developing countries, says CFR’s Isobel Coleman.| Council on Foreign Relations
Global warming affects snow and ice cover by increasing the amount of precipitation falling as rain instead of snow and by hastening snowmelt. Scientists have already observed these trends in the Western US. Atmospheric circulation may also be leading to an overall decrease in the amount of precipitation.| www.climatesignals.org
Drought monitoring at the national, regional, and local levels is an integral part of drought early warning, planning, and mitigation.| Drought.gov
Drought is generally defined as “a deficiency of precipitation over an extended period of time (usually a season or more), resulting in a water shortage.” As the different definitions at right illustrate, though, drought can be difficult to define—so difficult, in fact, that in the early 1980s researchers found more than 150 published definitions of drought, reflecting differences in regions, needs, and approaches. Some drought definitions are conceptual—an idea or concept—which...| Drought.gov
This report is an authoritative assessment of the science of climate change, with a focus on the United States. It represents the first of two volumes of the Fourth National Climate Assessment, mandated by the Global Change Research Act of 1990.| science2017.globalchange.gov
This report is an authoritative assessment of the science of climate change, with a focus on the United States. It represents the second of two volumes of the Fourth National Climate Assessment, mandated by the Global Change Research Act of 1990.| nca2018.globalchange.gov