Tropical forest soil warmed in experiments to levels consistent with end-of-century temperature projections released 55 percent more CO2 than control plots, exposing a previously underestimated source of greenhouse gas emissions, researchers reported recently.
Before humanity began loading the atmosphere with carbon pollution by burning fossil fuels, the input and outflow of CO2 into soil—one key element in Earth’s complex carbon cycle—remained roughly in balance.
Gases emitted by deadwood and decaying leaves, in other words, were cancelled out by microorganisms that feed on such matter.
But climate change has begun to upset that balance, according to a new study, published in Nature.
“Carbon held in tropical soils is more sensitive to warming than previously recognized,” lead author Andrew Nottingham, a researcher at the University of Edinburgh’s School of Geosciences, said.
“Even a small increase in respiration from tropical forest soils could have a large effect on atmospheric CO2 concentrations, with consequences for global climate.”
