Woody trunks and branches of trees in the wet tropical rainforests of Queensland are losing their ability to absorb excess carbon dioxide. That’s according to an analysis of 49 years’ worth of data, published in Nature today, which shows this “woody biomass” has switched from being a net carbon absorber to an emitter. And this shift occurred about 25 years ago. Ecophysiologist and study lead Hannah Carle, from Western Sydney University, said the historical assumption has been wet tropical rainforests around the world and Australia were “carbon sinks”. …But the new study showed woody biomass [was becoming] a carbon source because carbon lost to trees dying and decaying outstripped the carbon gained by trees growing to replace them. …This may be a sign that these Australian wet rainforests as a whole ecosystem were in decline, and could switch from being net carbon sinks to carbon sources in the future, according to the study.