Land use and climate pollution, 1990-2010. Values are for average annual greenhouse gas emissions, in gigatons of CO2 equivalent, for the agriculture and forestry sectors. Graphic: Climate Central

By John Upton
3 February 2015 (Climate Central) – Efforts to restrain deforestation are working, which means pollution from farming has increased in importance. The federal raids in Alta Floresta, Brazil surprised locals in 2005. The year before, nearly 60,000 acres of rainforest had been torn out of the municipality. Now farmers and loggers were being arrested by armed police, accused of environmental crimes. “It was a radical operation,” the newly elected mayor later recalled during an interview with a Princeton University researcher. “All our economic activity stopped.” A few years later, Brazil’s central bank made it harder for property owners there, and in 35 other blacklisted areas, to borrow money unless they proved they were protecting the rainforest. The campaign marked a sharp change from the 1970s, when the federal government, then a military dictatorship, had encouraged clearcutting. Now the federal government was cracking down on it — and doing so successfully. In 2010, fewer than 1,000 acres of Alta Floresta was deforested. Efforts such as these to slow deforestation have delivered some of humanity’s few gains in its otherwise lackadaisical battle so far against global warming. A gradual slowdown in chainsawing and bulldozing, particularly in Brazil, helped reduce deforestation’s annual toll on the climate by nearly a quarter between the 1990s and 2010. A new study describes how this trend has seen agriculture overtake deforestation as the leading source of land-based greenhouse gas pollution during the past decade. While United Nations climate negotiations focus heavily on forest protections, the researchers note that delegates to the talks ignore similar opportunities to reform farming. “The decline in deforestation over the past decade or two is a success story,” Rob Jackson, a professor at Stanford University’s earth sciences school, said. He was not involved with the new study. The deforestation slowdown has, “in large part,” he said, been driven by new forestry rules in Brazil, by the U.N.’s Reducing Emissions from Deforestation and Forest Degradation (REDD) program, which funds forest conservation, and similar policies elsewhere. The new study, led by the U.N. Food and Agriculture Organization and published in Global Change Biology, quantifies the reductions in climate pollution from the degradation and clearcutting of forests. Clearcutting most often clears space for agriculture, suggesting agriculture’s indirect climate impacts surpass the impacts of deforestation for timber and other commodities. The researchers aim to tally those indirect impacts later this year. This paper was an early step in a larger effort to better understand and report on the climate repercussions of how land is used. “Every year, we’ll have updates,” lead author Francesco Tubiello said. […] “We’re seeing an expansion of agricultural lands in some areas because of the growing global population,” Jackson, who is a co-chair of the Global Carbon Project, which studies the global carbon cycle, said. “We’re also seeing intensification of agriculture.” Although annual climate pollution from deforestation is declining, experts warn that recent gains could quickly be reversed. Deforestation in the Amazon rainforest spiked recently following nearly a decade of declines, for example, as farmers and loggers rushed to exploit loopholes in forest protection laws. Some parts of Central Africa are seeing deforestation in areas where it was not previously a problem. And cutting down trees can reduce moisture levels in a rainforest, which could cause parts of the Amazon to start dying off — even if everybody’s chainsaws simultaneously jammed. [more]

Farming Now Worse for Climate Than Clearing Forests