ARS | Publication request: Projected change in climate thresholds in the northeastern U.S.: implications for crops, pests, livestocks, and farmers

Submitted to: Mitigation and Adaptation Strategies for Global Change
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 2008
Publication Date: June 1, 2008
Citation: Wolfe, D.W., Ziska, L.H., Petzoldt, C., Seaman, A., Chase, L., Hayhoe, K. 2008. Projected change in climate thresholds in the northeastern U.S.: implications for crops, pests, livestocks, and farmers. Mitigation and Adaptation Strategies for Global Change. 13:555-575.

Interpretive Summary: Most prior climate change assessments for U.S. agriculture have focused on major world food crops such as wheat and maize. While useful from a global perspective, these results do not always apply on a regional basis. For example, in the Northeast, agriculture is dominated by dairy milk production, and high-value horticultural and forest crops such as apples, grapes, sweet corn, cabbage, and maple syrup. To determine impacts of climate change on agriculture for the Northeast we used two models, one that assumes no reduction in carbon dioxide emissions (¿business as usual¿ or BAU), the other, stabilization of emissions at a carbon dioxide value of 450 parts per million (ppm). Data from these model projections indicate that the Northeast is likely to experience warmer temperatures, a longer growing season and increased carbon dioxide levels. Although these changes could mean increased opportunities for new crops, the results also indicate that many crops will have yield losses associated with increased frequency of high temperature stress, inadequate winter chill period (vernalization) for optimum fruiting in spring, increased pressure from marginally over-wintering and/or invasive weeds, insects or disease, or other factors. Forecasts for warmer temperatures also suggest a decline in dairy production for the region. Overall, the impact on individual farm families and rural communities will depend on commodity produced, available capital, and timely, accurate climate forecast information. This information should be of interest to scientists, extension agents, farmers and policy makers.

Technical Abstract: Most prior climate change assessments for U.S. agriculture have focused on major world food crops such as wheat and maize. While useful from a national and global perspective, these results are not particularly relevant to the Northeastern agriculture economy, which is dominated by dairy milk production, and high-value horticultural and forest crops such as apples, grapes, sweet corn, cabbage, and maple syrup. We use statistically downscaled climate forecasts generated by two climate models (HadCM3 and PCM), run with UNIPCC future emission scenarios A1f1 a(BAU) and B1 (450 ppm CO2 stabilization) to forecast several climate thresholds of direct relevance to agriculture in the region. Warmer temperatures, a longer growing season, and increased CO2 could create new opportunities for farmers with sufficient capital to take risks on new crops (given that a new market for such crops could be developed). However, our results also indicate that many crops will have yield losses associated with increased frequency of high temperature stress, inadequate winter chill period (vernalization) for optimum fruiting in spring, increased pressure from marginally over-wintering and/or invasive weeds, insects or disease, or other factors. Forecasts of thermal heat index values for dairy cows indicate a substantial potential negative impact on milk production. Farmer adaptations to climate change will not be cost- or risk- free, and the impact on individual farm families and rural communities will depend on commodity produced, available capital, and timely, accurate climate forecast information.