New study helps assess climate sensitivity of tropical ecosystems
FRISCO — Tropical forest ecosystems are the lungs of the Earth, and they are breathing harder, releasing more carbon into the atmosphere, as global temperatures increase.
According to new research, the tropical carbon cycle has become twice as sensitive to temperature variations over the past 50 years. For every degree that temperatures in the tropics rise, two billion tons of additional carbon are released from tropical ecosystems. according to the study, published last week in Nature.
Professor Pierre Friedlingstein and Professor Peter Cox, from the University of Exeter, collaborated with an international team of researchers from China, Germany, France and the USA, to measure annual variations in CO2 concentrations.
Those changes can reveal the sensitivity of tropical ecosystems to future climate change, said Cox, explaining that existing earth system model simulations already show that that the ability of tropical land ecosystems to store carbon will decline over the 21st century.
“The increase in carbon dioxide variability in the last few decades suggests that tropical ecosystems have become more vulnerable to warming,” he siad.
Professor Friedlingstein, who is an expert in global carbon cycle studies added: “Current land carbon cycle models do not show this increase over the last 50 years, perhaps because these models underestimate emerging drought effects on tropical ecosystems”.
“This enhancement is very unlikely to have resulted from chance, and may provide a new perspective on a possible shift in the terrestrial carbon cycle over the past five decade,” said Xuhui Wang, of Peking University, lead author of the study.