By Chad Kruger
USDA recently released a report that provides a comprehensive interpretive review of the scientific literature on the impacts of climate change on agriculture in the U.S. This report was undertaken in response to the soon to be released 2nd National Climate Assessment – an effort that reviews the impact of climate change on several sectors of the U.S. economy. The USDA report, entitled Climate Change and Agriculture in the United States: Effects and Adaptation, can be accessed from the website of the USDA’s Chief Economist .
The report represents the most comprehensive assessment of the potential impact that climate may have on national agriculture published to date. This is important because it organizes the findings of many scientific studies and systematizes them in a way that makes it possible to appreciate the full scope of the challenge we face at the national level and will ultimately drive national investment for climate adaptation.
So, what does the report say and what does it mean?
Very succinctly, the report articulates that US crop and livestock production will likely become increasingly vulnerable to the accelerating changes in climate (elevated CO2, rising temperatures and altered precipitation) over the next 25 years. The impacts, however, will depend largely on location and production system and that vulnerability is ultimately dependent on how the agricultural community (in any given place) responds to the increasing and changing stressors. US agriculture has been remarkably resilient and adaptive over the past 150 years (much of which has been adaptation to government policies), but the question remains about whether changing climatic drivers may out-pace adaptation without more clear emphasis on planning and investment.
The largest emerging, national concerns for agricultural impacts and adaptation surround the increasing biotic stressors (weeds, diseases, insect pests, pollination cycles, etc.) and more erratic and extreme weather events, like the recent drought in the US corn belt. These are critical findings for two reasons: 1) these sources of stress are the most difficult for producers to manage – they are already a primary factor of cost and risk in production without considering climate change, and 2) these sources of stress are the most difficult for the scientific community to evaluate and project for the future. In fact, after water supply for irrigation, the two most frequent sets of questions I receive from stakeholders in the Pacific Northwest are about pests and extreme weather events, but unfortunately these aspects of agricultural climate change science are still in their infancy. The one thing that I can report is that there are several extremely talented and highly regarded scientists in the region that are now focusing their attention on understanding these challenges.
A final point, while this USDA report is focused on national concerns, a companion report, Climate Change in the Northwest: Implications for Our Landscapes, Waters, and Communities (Mote and Snover, forthcoming), reviews the effects of climate change in the US Pacific Northwest region of the US will be published by Island Press this spring. The agricultural chapter of this report was co-authored by several scientists on the REACCH project, including me. This chapter will be the most comprehensive review of available science on published literature for our region – and will be an invaluable resource for planning and investment in agricultural adaptation locally.