This thematic package in Choices celebrates the International Panel on Climate Change (IPCC) work, its Nobel prize and the significant contributions of agricultural and resources economists to the IPCC process and reports. These nine papers present work which overviews the major aspects of climate change and its implications for agriculture and natural resources written by people who have been intimately involved with the IPCC.

Agriculture will be influenced by future Climate changes. In order to see these influences and examine their implications one must obtain a climate change projection. Climate change projections can be obtained from Global Climate Models (GCMs) run under scenarios that are forced by the drivers of the climate system. This paper will give a very brief summary of the GCMs and scenarios then present projections for the next half-century.

This paper reviews the current state of knowledge and uncertainties about the economic impacts of climate change on agriculture. The evidence from the past several decades of research suggests that the aggregate impacts will be relatively small, but there will be important regional impacts, particularly in the poorest, most vulnerable parts of the tropics. These impacts suggest there is a potentially important role for policies that facilitate and enable adaptation.

Climate change will affect water resources through its impact on the quantity, variability, timing, form, and intensity of precipitation. This paper provides an overview of the projected physical and economic effects of climate change on water resources in North America (with a focus on water shortages), and a brief discussion of potential means to mitigate adverse consequences. More detailed information on this complex topic may be found in Adams and Peck (forthcoming) and in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4).

Some degree of climate change is inevitable, regardless of the severity of action that is undertaken, and this implies a need for adaptation by U.S. agriculture and forestry. Adaptation is nothing new to these sectors—it is a fundamental and ongoing activity. This paper discusses adaptation possibilities, facilitating mechanisms, and associated challenges. The authors also discuss the inevitability of shifts in the distribution of production across the country, with some areas becoming economically less productive, while others become more productive.

The paper discusses the diversity, complexity, and affordability of agricultural greenhouse gas emission mitigation options. Land competition and commodity market price feedbacks limit the capacity of agricultural strategies. Furthermore, environmental co-effects, emission leakage, and changes in income distribution may cause substantial positive or negative side effects to land based mitigation efforts. Competitive, economic mitigation potentials of agriculture should be assessed at the global level and integrate major side effects.

Under Kyoto rules, it is possible to obtain credit for reducing CO2 emissions by removing of CO2 from the atmosphere and storing it as carbon in terrestrial ecosystems. This article argues that, compared to emissions reduction, this can be very costly. Further, the determination of such offset credits and how they compare with emissions reduction is fraught with so many problems that they should not be permitted to substitute for real CO2 emissions reduction.

This paper reviews several pros and cons of policy related to crediting reductions in deforestation in carbon markets. Pros include potential cost savings, while the cons include contracting, verification, and monitoring issues, among others. The paper examines difficulties with implementation, including transactions costs.

Agriculture may help mitigate climate change risks is by helping reduce greenhouse gas (GHG) emissions. This paper looks at this issue. One way of doing this is by providing substitute products that can replace fossil fuel intensive products or production processes. Production of biofeedstocks for bioenergy achieves this, where the biofeedstocks are traditional products, crop residues, wastes or processing byproducts. The forms of bioenergy include electrical power or liquid transportation fuels e.g. ethanol or biodiesel.

This paper reviews legislation that proposes policies to reduce U.S. greenhouse gas emissions to slow climate change. We address relative merits of cap and trades systems, pollution taxes, and other policy instruments and how agricultural emissions would be treated in proposed systems. We offer some suggestions for extending price incentives to agricultural sources in a manner commensurate with other emissions sources.