Brazil may see a mass migration of crops and farm workers from huge swaths of currently tillable lands to more temperate zones as global warming takes hold, according to leading climate experts in the country.
Longtime Brazilian climate researcher Hilton Silveira Pinto points to the drought that’s cutting grain and coffee output this year as an indicator that rising global temperatures may already be impacting the country’s crops.
"This is a taste of what is to come in the future," said Pinto, a professor at the Center for Meteorological and Climate Research Applied to Agriculture at the University of Campinas.
A study co-authored by Pinto that looks at projected warming trends shows Brazil’s soybean production may drop by as much as 24 percent and wheat output as much as 41 percent by 2020 as climate change reduces areas where the crops can grow.
Because Brazil is increasingly helping to feed the world, the import of that isn’t just Brazil’s problem. The nation last year dethroned the U.S. as the world’s top soybean exporter -- it sold 41.9 million tons to Asia, Europe and the Middle East last season -- and has led the world in sugar and coffee production for more than a century. It also exports more beef and orange juice than any other nation on earth.
Agriculture accounts for 25 percent of Brazil’s gross domestic product and more than one third of its annual exports. With its ample water resources and year-round temperate climate, Brazil has also attracted billions of dollars in agribusiness investments by opening vast tracts of tropical hinterland to farming and applying state-of-the-art technology to expand yields across all manner of crops.
While the connection of warming to droughts and extreme weather is still being studied, there’s no doubt that warmer temperatures are affecting global crop output -- worldwide wheat yields are declining by about 2 percent a decade and those for maize by 1 percent, the United Nations said in a March 31 report.
Major grain producers in cooler climates such as Canada and Russia may fare better than Brazil as much of its tropical agriculture already operates at the upper limit of heat tolerance, said Eduardo Assad, a researcher at the government’s Embrapa agricultural technology agency who co-authored the study with Pinto.
In Brazil, heat and drought are already taking their toll. The worst dry spell in six decades is erasing an estimated 5 million metric tons from Brazil’s grain harvest this year, about the size of Egypt’s annual corn crop.
Hotter weather is already chasing some coffee production up to higher altitudes. Coffee growers in Sao Paulo and Minas Gerais states have been the hardest hit so far by drought and heat waves.
"If the unprecedented high temperatures we saw repeat themselves, we’d have a serious problem," said Mauricio Miarelli, head of the Franca, Brazil-based growers association Cocapec.
Crop shifts may cause a mass migration of millions of rural workers, requiring major investments in infrastructure and logistics to accommodate them, according to Assad.
"Brazil’s agriculture will be rearranged," he said. "Climate change is on our heels."
In the northeastern state of Bahia, three consecutive years of unusually intense drought that cut soybean output 16 percent in 2013 have triggered concern even among hardened farmers used to the harsh, semi-arid climate, said Jairo Vaz, the state agriculture secretary’s cabinet chief.
"Undeniably the droughts have become longer, more pronounced and temperatures have risen -- that hit our farmers hard," Vaz said. The state’s 670,000 family farmers have lost roughly half of their livestock over the three years, he said.
Soybeans in Chicago extended gains to a 10-month high today, rising as much 0.8 percent to $15.21 a bushel and corn climbed 0.4 percent to $5.0525 a bushel.
About a dozen new varieties of beans and corn that are more resistant to extreme heat and dryness have shown promising results, Embrapa’s Assad said. Still, with Brazil growing 800 to 900 crops, progress in research and development has been too slow and investments too small, he said.
Other measures pursued by the government include promoting an integration of farming and forestry where shade from trees reduces temperatures and maintains humidity.
The technique known as agro-forestry lacks the scale to quickly transform the way soybeans and corn are grown in areas like Mato Grosso, a state twice the size of Germany covered with crops that stretch beyond the horizon.
"You can’t apply this technology overnight," Caio Rocha, Brazil’s secretary for agriculture policies, said in a phone interview. "We’ll have to show farmers that it’s in their financial interest to do so."
The impact of global warming on Brazil’s agriculture is far from consensus. Donald Keeney, a meteorologist at MDA Weather Services in Gaithersburg, Maryland, is among meteorologists who expect precipitation in central and northeastern Brazil to decline, paring agricultural output -- while production should increase in areas closer to the poles.
Scott Yuknis, the lead forecaster with Climate Impact Co. in Middleboro, Massachusetts, doesn’t agree. He ascribes the drought in Brazil this year as part of the ocean temperature changes that induce cycles that last several decades.
While experts like Assad and Pinto agree with Secretary Rocha that Brazil may be able to offset part of climate change with new technology, they argue progress has been too slow and assumes temperatures will not rise more than 2 degrees on average by the end of this century.
"The world is failing to slow emissions, meaning temperatures may rise more than 2 degrees," said Assad. "If that happens, science has no answers for impact mitigation, we’ll be in uncharted territory."