In light of the updated IPCC report and other extensive studies on Climate Change, this Choices theme revisits the issue for agriculture and addresses some of the controversies, imperatives and unmet expectations that have arisen since the release of the first IPCC report, and considers the challenges that lie ahead.

Although all aspects of food security are potentially affected by climate change, our understanding of the likely impacts of climate change on food security is very limited. This article explains this gap in our knowledge and suggests ways to improve our understanding of this vital issue with better data and models.

This article reviews the latest climate change impact assessments on crop productivity in the United States. Under current agricultural practices, yield declines are expected for the major crops grown in the United States. A large array of adaptation strategies can be implemented to alleviate those impacts.

This article summarizes future potential global and U.S. changes in climate and observes that there is a need for adaptation in U.S. agriculture regardless of climate policy. It then considers adaptation options for agriculture, for U.S. farmers and more broadly, the economics of adaptation, and agricultural adaptation challenges and opportunities.

Adaptation to climate change is virtually inevitable in the next 30 years. Many adaptation actions will be carried out by industry, but a substantial public role is also involved. Also there are limits and needs for funds to be considered. Adaptation may be the dominant role for the forseeable future.

By now, climate policies were expected to create carbon markets that would induce large reductions in agricultural greenhouse gas emissions. This article offers political, technical and economic reasons why these large-scale changes have not yet materialized, what has transpired instead, and what could produce more significant reductions in the future.

Public and private sector entities are considering non-carbon market approaches for mitigating GHG emissions in the agricultural sector. This paper discusses three: targeting GHG mitigation in the Department of Agriculture’s conservation and renewable energy programs, facilitating private supply chain initiatives to reduce emissions, and supporting joint public-private GHG mitigation efforts.