On May 6, the U.S. Global Change Research program released its National Climate Assessment, which summarizes the impacts of climate change in the U.S. now and into the future.  The report was produced by a team of 300 experts guided by a 60 member federal advisory committee.  It was subject to review by the public and experts, including numerous federal agencies and a panel of the National Academy of Sciences.

An overview of the report states that “climate change is already affecting the American people in far-reaching ways. Certain types of extreme weather events with links to climate change have become more frequent and/or intense, including prolonged periods of heat, heavy downpours, and, in some regions, floods and droughts. In addition, warming is causing sea level to rise and glaciers and Arctic sea ice to melt, and oceans are becoming more acidic as they absorb carbon dioxide. These and other aspects of climate change are disrupting people’s lives and damaging some sectors of our economy.”

The assessment contends that climate change is affecting every region of the country and key sectors of the U.S. economy and society, including agriculture. The report puts emphasis on the need to combat the current challenges presented by climate change and increase our preparedness for future changes.  The 25 page chapter on agriculture can be viewed here.

The report discusses U.S. agriculture and forestry as sectors that will be impacted by adverse climate conditions and extreme weather events, but also sectors that can contribute to solutions and mitigate climate change impacts through things such as renewable energy production, carbon sequestration and land management and cropping practices that reduce greenhouse gas emissions.  The six “key messages” on agriculture are:

1. Climate disruptions to agricultural production have increased in the past 40 years and are projected to increase over the next 25 years. By mid-century and beyond, these impacts will be increasingly negative on most crops and livestock.

2. Many agricultural regions will experience declines in crop and livestock production from increased stress due to weeds, diseases, insect pests and other climate change induced stresses.

3. Current loss and degradation of critical agricultural soil and water assets due to increasing extremes in precipitation will continue to challenge both rainfed and irrigated agriculture unless innovative conservation methods are implemented.

4. The rising incidence of weather extremes will have increasingly negative impacts on crop and livestock productivity because critical thresholds are already being exceeded.

5. Agriculture has been able to adapt to recent changes in climate; however, increased innovation will be needed to ensure the rate of adaptation of agriculture and the associated socioeconomic system can keep pace with climate change over the next 25 years.

6. Climate change effects on agriculture will have consequences for food security, both in the U.S. and globally, through changes in crop yields and food prices and effects on food processing, storage, transportation, and retailing. Adaptation measures can help delay and reduce some of these impacts.

The report was commended by groups such as the 25x'25 Alliance for its, “candid appraisal of changing climate conditions that are currently effecting agricultural production and could have a broad negative impact on the nation's farmers, ranchers and forestland owners as the century passes.”