Caption: Global cropland distribution and average annual yields between 1998 and 2002. Highest crop yields are in temperate regions of Western Europe and North America.
Map: courtesy Paul West, UW-Madison Center for Sustainability and the Global Environment and UW-Madison Center for Limnology.
Date: 2010
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Caption: Changes in carbon stocks due to cropland conversion. Loss of forests and other native ecosystems is steadily eroding the world's natural carbon reservoirs, according to 2007 data collected by the International Panel on Climate Change. The problem is greatest in the tropics, as native tropical ecosystems tend to store more carbon.
Map: courtesy Paul West, UW-Madison Center for Sustainability and the Global Environment and UW-Madison Center for Limnology.
Date: 2010
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Caption: Combining global cropland distribution and changes in carbon stocks due to cropland expansion into native ecosystems shows that carbon loss per ton of annual crop yield is nearly three times as high in the tropics compared to temperate regions.
Map: courtesy Paul West, UW-Madison Center for Sustainability and the Global Environment and UW-Madison Center for Limnology.
Date: 2010
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Caption: The tradeoffs between the release of carbon to the atmosphere and agricultural production are markedly different between the world's temperate and tropical regions. In this representation, for each hectare of land cleared for agriculture, each rail car is equivalent to 68 tons of carbon released to the atmosphere and each bushel represents 3.9 tons of maize produced. A study in the Proceedings of the National Academy of Sciences by UW-Madison graduate student Paul C. West in the UW-Madison Center for Limnology and colleagues documents the tradeoff.
Map: courtesy Paul West, UW-Madison Center for Sustainability and the Global Environment and UW-Madison Center for Limnology.
Date: 2010
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