There is growing interest and significant research on the impact of climate change on agriculture and the possible contribution of agriculture in mitigating climate change.  The Center of Sustainable Resource Development at the University of California at Berkeley, the Department of Food and Resource Management at the University of Florida, and the Environmental Protection Agency sponsored a conference to address these issues.  The conference was held at Gainesville, Florida, on September 10, 1999.  The conference consisted of presentations on the impact of climate change on U. S. agriculture, agricultural and resource policies to mitigate climate change, and, in particular, how pests control issues affect the impact of climate change on agriculture.

The following text highlights the significant elements presented by the conference participants. Further information on the conference agenda may be found at the University of Florida website.

• Andrew Manale of the US Environmental Protection Agency summarized the results of the two previous workshops on climate change and agriculture presented by UC Berkeley and sponsored by EPA. The first workshop focused primarily on the question of whether or not climate change will have a positive or negative economic impact on producers of major commodity crops. It concluded that, though the science of predicting future economic impacts may be uncertain, widespread adoption of certain agricultural practices can serve as an inexpensive insurance policy that pays dividends in terms of improvements in water quality and soil productivity. The second workshop explored economic opportunities that may arise for agriculture to mitigate the impacts of climate change through practices that increase soil carbon levels. This, the third workshop, is the first to explore issues of broad interest not just to Midwestern agriculture but also to agricultural producers in the Southwest and California and the Southeast.

 
• Results presented at the conference suggest that some studies on the impact of climate change have ignored two important phenomena. First, most studies recognize that the increase of carbon dioxide in the atmosphere will increase yields. However, as reported by David Lincoln from University of South Carolina and Hartwell Allen from the University of Florida, increased atmospheric levels of carbon dioxide will reduce the nutritional content of leaves, sometimes between 10% to 20%. Hence, the nutritional value of crops grown for food may decline. Second, climate change will affect agriculture through its impact on pest management. For example, freeze and cold weather are great natural pest control mechanisms and as temperatures increase this will reduce its effectiveness.

 
• Andrew Gutierrez from the University of California in Berkeley stated that climate change will affect dynamics and interaction among species and it will affect and change the pattern of pest damage and pest control strategies. He presented examples of how climate change may disrupt the effectiveness of biological control by suggesting that models to evaluate these changes can be constructed using crop pest interaction models and geographic information systems.

 
• Paul Jepson from the Oregon State University suggested that an increase in temperature may increase the need for application of pesticides, may reduce pesticide effectiveness and may increase residues, thus, leading to longer reentry periods and as a result, raising food safety concerns. 

 
• Mathew Ayres from Dartmouth College suggests that faster mobility of pests, relative to trees, may make trees especially vulnerable to pest damage with climate change. Trees will also suffer greatly from the reduction of pest control impact of cold temperature. With climate change trees will suffer from risk of fires. James Bunce from USDA ARS suggests that temperature increase may exacerbate wheat problems and expects north-world spread of problematic exotic weeds. 

 
• Evan Sieman from Rice University presented general frameworks of pest and beneficials to climatic issues. His results suggest the increase of carbon dioxide in the atmosphere and higher temperatures are likely to result in pest damage. All the speakers suggest that modeling techniques are available to quantify the impact of pest control and carbon increase on pest control and climate change and that it is a neglected area of research that has to be further pursued. 

 
• Marcia Mulkey, Director of Pesticide Programs, U.S. Environmental Protection Agency, emphasized the importance of this line of research and she argues that new EPA aims to incorporate more sound biological principles, and protect the most vulnerable groups in its pesticide policies. She explained that that is the reason for the use of regulatory limits on the application of chemicals that have the same toxic mode of operation and special emphasis on protecting infants in FQPA. The most recent regulatory actions also suggest that the agency is sensitive to the needs and concerns of the producers. She emphasized the importance of a better understanding of climate change and development of effective policies for its mitigation.

 
• Bruce McCarl of Texas A&M discussed recent findings on the economic impact of climate change on agricultural producers and consumers. The simulation studies involve significant interdisciplinary collaboration where climate information is integrated with agronomic models to predict crop yields. The results of these models are integrated with economic models to predict land-use allocation among crops, commodity output, and prices and will lead to economic well being of consumers and productspresented results of existing studies on the impact of climate change on US agriculture and the food sector. The predictions suggests that the overall effect of increased carbon dioxide levels will be negligible, but some regions will be gainers (the upper mid-west and the west) and others will be big losers (the southeast). He suggested that the build up of carbon dioxide in the atmosphere can be mitigated by biological sequestration of carbon in trees or agricultural soil, or by converting to alternative energy forms. The most cost effective way to effect such mitigation is by financial incentives to reduce energy use. 

 
• Ujjayant Chakravorty from Emory University asserted that the prospects of the Kyoto protocol are uncertain now. Nevertheless, some agreement will likely be signed in the future. Any agreement will entail targeted reductions in carbon emissions by countries, emission reduction credits for projects in developing countries, and emission reduction credits for carbon sequestration activities. The negotiation between, as well as within countries, dictated by political economic situations and changes in weather condition will determine the outcome. Another issue is the extent to which emission reduction credit could be traded. Chakravorty argues that investment in research and development in alternative technologies, in particular solar, and assessment of the role of nuclear technology will be very important in determining the build up of carbon in the atmosphere and climate change policies. Some of his more optimistic simulations expect that the alternative technologies will be economically feasible and dominant in 30-50 years. 

 
• Rattan Lal from Ohio State University argues that sequestering carbon in agricultural and forest soils can alleviate reduce the rate of buildup of atmospheric carbon dioxide and buy time for society to switch to alternative fuels. His calculations suggests that sequestration of carbon in agricultural soils through the adoption of no-till and other green practices is cost effective and provides other benefits beside reducing atmospheric levels of carbon dioxide, such as water quality, reduced flood and drought risks, and increased soil productivity. He states that the science of soils is sufficiently advanced to permit implemention of a market in carbon credits that can be effectively monitored and managed. Though the soil has a limited capacity to sequester carbon, it can meet much of U.S. targeted reduction for a period of 30 years. Soil Carbon sequestration can also play a major role in supporting farm income and building up depleted soil resources in the U.S. and in many other countries. 

 
• Andrew Schmitz from the University of Florida argued that there can be a significant loss of efficiency if there are limits in ability to trade carbon emission rights. He illustrated that with significant differences in the marginal cost of carbons in sectors and nations, there are immense gains from trade and markets in carbon emission rights. 

 
• Margot Anderson from the USDA stated that the agency is conducting research on a wide range of activities to control carbon emissions, including sequestration in soils and trees, through reduction in energy use, and through changes in agricultural practices. She emphasized the important role that financial incentive can play in inducing transition towards activities that reduce emissions or increase sequestration of carbon. She suggested that future versions of the Kyoto Protocol or similar agreement are likely to have mechanisms that will acknowledge the role of carbon sequestration in forests and agricultural soils and hence enable agriculture to benefit from activities that will abate climate change. 

 
• David Zilberman of the University of California, Berkeley argued that the existing impact of climate change on food and agriculture tends to underestimate its cost because they neglect to take into account cost o f adjustments, negative effects on food quality, pest control adjustment. Furthermore, some studies ignore likely growth in populations. The conference suggested some new avenues for research that are likely to lead to better estimates. He also suggested that further research and experimentation in mechanisms, including trading, to induce soil carbon sequestration should be taken given the potential of these activities to abate climate change.