Alex Fox writes:

The Amazon rainforest may now emit more greenhouse gases than the famously lush ecosystem absorbs, according to new research.

Long considered to be a bulwark against climate change because of its capacity to absorb carbon dioxide, a new study suggests rising temperatures, increasing drought and rampant deforestation have likely overwhelmed the Amazon’s ability to absorb more greenhouse gases than it emits, reports Craig Welch for National Geographic.

The sobering findings appear in a new study published earlier this month in the journal Frontiers in Forests and Global Change that calculates, for the first time, the net emissions of greenhouse gases from both human and natural sources in the Amazon Basin, reports Liz Kimbrough for Mongabay.

A key distinction in appreciating the study’s findings is that they do not just concern carbon dioxide, according to Mongabay. Though carbon dioxide often gets top billing in discussions around climate change, there are many other significant greenhouse gases, including methane, nitrous oxide, aerosols and sooty black carbon.

So, while the Amazon still absorbs and stores a prodigious amount of carbon, its net greenhouse gas emissions have tipped from negative to positive—not just because its capacity to absorb carbon dioxide has been damaged by human activity, but also because the transforming landscape has increased emissions of these other greenhouse gases. [Continue reading…]