Sweet news for the environment and sugarcane farmers: the tasty grass has been found to cool the surrounding air by more than 1.5 degrees Fahrenheit, compared with other crops or pasture forage.
What makes sugarcane so cool? It reflects more sunlight and exhales more moisture than other crops, like corn and soybeans, according to a study published in Nature Climate Change.
“It's a potential win-win for the climate. Using sugarcane to power vehicles reduces carbon emissions, while growing it lowers the local air temperature," said ecologist Scott Loarie, of the Carnegie Institution for Science and one of the authors of the study, in a press release from the institution.
To do their calculations, the environmental scientists used data from hundreds of satellite images of 733,000 square miles of the cerrado, a vast savanna in Brazil. They measured temperature, reflectivity and evapo-transpiration, the water lost from the soil and from plants as they exhale water vapor.
Converting from wilderness to crop/pasture warmed the cerrado by 2.79 degrees Fahrenheit (1.55 degrees Celsius) on average, but later changing to sugarcane cooled the surrounding air by an average 1.67 degrees Fahrenheit (0.93 degrees Celsius), Loarie and colleagues reported.
The authors noted that the benefit is only realized if the cane is grown on land converted from other crops. The benefit is lost when the sugarcane is grown on previously untouched land.
"It's becoming increasingly clear that direct climate effects on local climate from land-use decisions constitute significant impacts that need to be considered core elements of human-caused climate change," said ecologist and co-author Greg Asner.
Sugarcane may keep farmland cooler, but it fans the flames of international debates.
The discovery comes in the wake of months of discussion between the United States and Brazil over ethanol. Brazil produces ethanol from sugarcane at a lower cost per volume than the U.S. produces ethanol from corn. But the U.S. outpaces Brazil in overall production and maintains hefty tariffs and subsidies. This has led to a complicated situation that keeps diplomats busy and may be keeping prices at the pump high.
Brazil dropped its 20 percent ethanol tariff last year in an effort to encourage the United States to drop its trade barriers.
“Consumers win when industries compete. Brazilian ethanol producers are willing to compete for consumers. What about American producers?” said Joel Velasco, an adviser to and former chief North American representative of the Brazilian Sugarcane Industry Association, in a press release.
“The best way to cut energy costs and reduce global dependence on oil is to give consumers more choices and make providers of different energy sources compete in open markets,” Velasco said.
The United States is the world's largest producer of ethanol, but the American ethanol market is complicated by subsidies and tariffs. In December 2010, U.S. lawmakers voted for the one-year extension of a 54 cents per gallon import tariff as well as the Volumetric Ethanol Excise Tax Credit (VEETC), a 45 cents per gallon subsidy on ethanol blended with gasoline.
This legislation makes American ethanol production more competitive, but results in higher prices at the pump for consumers, according to analysis by Robert Rapier, writing for Forbes:
"This essentially eliminates the competition for domestic ethanol producers, which for consumers also reduces the opportunity to save money on their fuel costs," Rapier reported.
Some U.S. legislators believe that the tariffs and subsidies are in fact illegal under World Trade Organization rules.
"I believe the WTO would rule against the United States because it's clearly a subsidy that is neither warranted nor in keeping with WTO regulations," Sen. John McCain of Arizona told reporters after meeting with Brazilian President Dilma Rousseff in Brasilia, Brazil.
"I'm unalterably opposed to ethanol subsidies," said McCain.
"We agree with the president here that [the U.S. tariff] should not be there," Wyoming Sen. John Barrasso added.
IMAGE 1: Sugarcane (Saccharum spp.) (Wikimedia Commons).
IMAGE 2: Sunset on the cerrado in Goias, Brazil (Wikimedia Commons).
IMAGE 3: E85 fuel pump for sale at a regular gasoline station in Washington, D.C. (Wikimedia Commons).