Carbon Fertilization

The extent to which carbon fertilization could alleviate any adverse effects of global warming on agriculture has been a central issue in analysis of the severity of these effects. Carbon dioxide is an input in photosynthesis, which uses solar energy to combine water and carbon dioxide to produce carbohydrates, with oxygen as a waste product.1 In addition, higher atmospheric concentrations of carbon dioxide reduce plants' stomatal (pore) openings and hence the loss of water to respiration....

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Viewed in this way, the irrigation issue raises two questions for most model estimates. First, have they included the costs of additional irrigation, which requires large capital outlays Second, have they carefully considered the availability of water for additional irrigation The broad answer to both questions would seem to be in the negative, suggesting that the Ricardian models may well tend toward an optimistic bias regarding treatment of irrigation. The seminal empirical Ricardian function...

Introduction and Overview

In the long list of potential damages from global warming, the risk to world agriculture stands out as among the most important.1 In the development of international policy on curbing climate change, it is important for policymakers to have a sense of not only the aggregate world effects at stake but also the distribution of likely impacts across countries, for reasons of equity. This study seeks to sharpen understanding of the prospective impact of unarrested global warming on world...

Mapping from 1 Cell Assignments to National Climate Data

The first step is to convert the cell-to-country data in the GridCtry dataset in terms of latitude and longitude into the present study's standardized grid structure. Following the equations in the definitions above, the grid code numbers are first broken into column number i and row number j. In Excel, RIGHT ( cell containing 139189 ,3) 189 i. That is, the three rightmost characters of the grid code number give the column number i. LEFT ( cell containing 139189 ,3) (139189 - 189) - 1,000 139...

Country Level Climate Results Present Day and for 207099

The present and future climate estimates are calculated at the level of each of the approximately 2,800 land-based cells in the standardized grid.3 Table 4.2 reports the result of averaging these estimates at the level of 116 individual countries (68), regions (10), or subzones for the seven largest countries (38). Definitions of the multicountry regions and large-country subzones are in appendix D. Development of the estimates for agricultural land and output within each subzone of the large...

Comparison to Estimates in the Model Source Studies

The analysis above has applied models developed by other authors to detailed future climate data as calculated in this study to obtain estimates of the impact of global warming on agricultural potential. The authors of these models have in some cases provided their own estimates of global warming impact, so it is important to compare their results with those here. 29. Developing Europe in table 6.1 shares Russia, Poland, Romania, Southeastern Europe, and Ukraine with former Soviet Union and...

Plan of the Book

Chapter 2 briefly surveys the findings of several leading existing studies on the agricultural impact of climate change. Chapter 3 discusses three fundamental issue areas carbon fertilization, irrigation, and induced effects from international trade. Gauging the influence of higher atmospheric concentrations of carbon dioxide on crop yields (carbon fertilization) is crucial to arriving at meaningful estimates of agricultural impact. Impact estimates may be unduly optimistic if they fail to...

Rosenzweig et al Crop Model Results

Rosenzweig and Iglesias (2006) provide a query-based database that returns estimates of the impact of prospective global warming, under alter 16. The entries in appendix table F.2 correspond to those in the final column of table 5.6 after shrinkage to take account of the ratio of net revenue to output. 17. The coefficient of variation is calculated as the square root of the sum of squared residuals of each of the six estimates from the average of the six, divided by the average (and reported in...

Ricardian Estimates for Developing Countries and Canada

For the Ricardian estimates used in this study, the Mendelsohn and Schlesinger (1999) cross-section model estimated for the United States provides a default model for application to climate projections for countries and regions in which no directly estimated function is available, as discussed later. More recent models estimated explicitly for several important developing countries and regions provide a preferable basis for the estimates developed in the present study for those countries and...

Subzone Farm Area and Output

Subzone data for farm area and output for the larger countries are relatively accessible for Australia, Brazil, China, and the United States but not for Canada, India, and especially Russia. For Australia, the Australian Bureau of Statistics (ABS 2005) provides data on farm area and value of agricultural products sold by province, and for all the provinces there is an obvious mapping to the specific geographical subzone (although for two provinces, the amounts are divided evenly between the...