Although people living in poverty are among the most vulnerable to a warming planet, some of the world’s poor could end up winners in the climate change shuffle. As heat and drought drive crop yields down, basic commodity prices will go up. That will harm some—and help others.

“There are really very different effects on poverty depending on which poor people you look at,” says David Lobell, an assistant professor of environmental earth system science at Stanford University. “Farmers are getting hit with lower yields, but the prices of the things that they’re selling go up enough that they actually become less poor as a result.” The effects could be large enough to lift many agriculture-specialized households in Asia and Latin America out of poverty.

And it could happen quite soon. “It’s not implausible that even in the next 20 years, climate change could drive prices up considerably.”

These projections differ from most in that Lobell and colleagues consider a range of possible productivity scenarios instead of just the most likely one. As an agricultural ecologist, Lobell compiled plausible yields for six different crops in the year 2030. He used as the worst case scenario not what happens “if things go really, really, really, really bad, but just if things go a little bit worse than we expect.” He and his coauthors then fed these scenarios into the Global Trade Analysis Project general equilibrium model to see what happens to food markets around the world. “What we found was that there’s a pretty big range of potential price impacts of climate change,” Lobell says. It is most likely that effects 20 years from now will be small, “but there could be as large as 30 percent increases” in the price of cereals.

The researchers then used these price impacts to model what happens to incomes, cost of living, and net poverty levels for poor households who make their living in different ways. A poor Indonesian rice farmer would take home more money if the price of rice went up. In Bangladesh, on the other hand, most of the poor who work in agriculture are wage laborers, not landowners. So when prices go up, most people get poorer. “Climate change could be a major driver of poverty change even short term. It’s something that should be on the radar screen of most people thinking about development and poverty,” says Lobell, but understanding where to prioritize efforts is not easy. “It’s not necessarily just going to be where the yield changes are the biggest, or where the overall poverty levels are the biggest.”

Flexibility is important. “You need to have the capability of responding to a variety of potential climate impacts, and not just one,” says Gary Toenniessen, a managing director of the Rockefeller Foundation who leads the strategic direction for the foundation’s initiatives in agricultural development. “What we’re trying to do is help African agricultural research and development institutions build climate change resilience into their routine agricultural research work.”

Thomas W. Hertel, Marshall B. Burke, and David B. Lobell, “The Poverty Implications of Climate-Induced Crop Yield Changes by 2030,” GTAP Working Paper 59, 2010.

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