The most recent National Climate Assessment Report was released in November 2018 and continues to identify and predict the long-term effects of global climate change in the U.S. Reports in this series have established that the global climate is changing and that greenhouse gases from human activity are the dominant cause and that there is no alternative explanation supported by observable evidence. The reports point out that the increasing global temperature is resulting in changes in surface, atmospheric, and oceanic temperatures; melting glaciers; diminishing snow cover; shrinking sea ice; rising sea levels; ocean acidification; and increasing atmospheric water vapor. The most recent report includes specific impacts to agriculture, rural populations, and U.S. regions.
Keys messages nationally for agriculture and rural communities highlight reductions in the resource base, health challenges, and more, and point to issues that will require adaptation:
- Reduced Agricultural Productivity—Food and forage production will decline in regions experiencing increased frequency and duration of drought. Shifting precipitation patterns and high temperatures will intensify wildfires that reduce forage on rangelands. Supplies of water for irrigation will be depleted and the incidence of crop and livestock pests and diseases will expand.
- Degradation of Soil and Water Resources—Degradation of crucial soil and water resources will expand as extreme precipitation events increase in agricultural regions. Crop production will be threatened by excessive runoff, leaching, and flooding, leading to soil erosion, degraded water quality, and damage to rural community infrastructure.
- Health Challenges to Rural Populations and Livestock—Challenges to human and livestock health are growing due to increased frequency and intensity of extreme heat conditions. Heat stress contributes to health problems in humans (including heart attacks) and economic losses from livestock.
- Vulnerability and Adaptive Capacity of Rural Communities—Residents in rural communities often have limited capacity to respond to climate change impacts due to poverty and limitations in community resources. Communication, transportation, water, and sanitation infrastructure are vulnerable from climate stressors.
In addition, key messages for the Pacific Northwest point to the exposure of some of our natural and community resources. Climate change is already affecting the Northwest’s natural resources which support livelihoods, provide a foundation for rural, and tribal communities, and strengthen local economies. Climate and extreme events are already endangering a wide range of wildlife, fish, and plants which are tied to tribal subsistence culture and popular outdoor recreation. Water, transportation, and energy infrastructure face challenges from extreme weather events. Organizations and volunteers that make up the social safety net are stretch thin and will be further challenged by the increasing frequency of extreme events. And, communities on the front line of climate change experience the first and often the worst effects including tribes, those dependent on natural resources for their livelihoods, and the economically disadvantaged.
The 186-page Report-in-Brief is available as a downloadable PDF.