In Indiana, Using models that blend global economics, geography, ecology and environmental sciences is essential to understanding how changes in trade and natural systems in one part of the world affect those in another, a review concludes.
Tom Hertel, distinguished professor of agricultural economics, collaborated with an interdisciplinary team of experts led by Jianguo Liu of Michigan State University to determine how systems integration – using holistic frameworks to model many components of both human and natural systems – could shed insights on how activities in one part of the world can have significant impacts on distant regions.
Previous “farm-to-fuel tank” analyses showed that production of corn ethanol could reduce annual carbon dioxide emissions in the U.S. Aided by this research, policymakers passed the Renewable Fuels Standard requiring that fuel sold in the U.S. contain a certain amount of renewable fuels, such as corn ethanol.
But the analyses had missed key components of global trade and land use, Hertel said: While land in the U.S. previously used to grow corn for food switched to corn for grown for ethanol, the global demand for corn for food and livestock did not decrease. This could cause other countries to clear land for crops, releasing additional carbon dioxide through the land conversion process.
Hertel and fellow researchers used systems integration modeling to show that, over a 30-year production period, emissions from land use change would largely offset the direct gains from producing the mandated amount of corn ethanol.
“It turns out that the global effects of this U.S. policy are quite large – clearly large enough to call into question the regional benefits of ethanol production,” he said. “Biofuels are a great example of how the absence of a systems integrated approach led to misleading advice and misguided policy.”