Science@NASA: Good News on Forests and Carbon Dioxide

[bystander]

Good News on Forests and Carbon Dioxide
NASA Science News | Science@NASA | 2014 Dec 31

[i]A new NASA study suggests that tropical forests, like this one in Malaysia, absorb more atmospheric carbon dioxide than is absorbed by forests in Alaska, Canada and Siberia. [b]Image Credit: Wikimedia Commons[/b][/i]

---

A new NASA-led study shows that tropical forests may be absorbing far more carbon dioxide than many scientists thought, in response to rising atmospheric levels of the greenhouse gas. The study estimates that tropical forests absorb 1.4 billion metric tons of carbon dioxide out of a total global absorption of 2.5 billion -- more than is absorbed by forests in Canada, Siberia and other northern regions, called boreal forests.

"This is good news, because uptake in boreal forests is already slowing, while tropical forests may continue to take up carbon for many years," said David Schimel of NASA's Jet Propulsion Laboratory, Pasadena, California. Schimel is lead author of a paper on the new research, appearing online in the Proceedings of the National Academy of Sciences.

Forests and other land vegetation currently remove up to 30 percent of human carbon dioxide emissions from the atmosphere during photosynthesis. If the rate of absorption were to slow down, the rate of global warming would speed up in return.

The new study is the first to devise a way to make apples-to-apples comparisons of carbon dioxide estimates from many sources at different scales: computer models of ecosystem processes, atmospheric models run backward in time to deduce the sources of today's concentrations (called inverse models), satellite images, data from experimental forest plots and more. The researchers reconciled all types of analyses and assessed the accuracy of the results based on how well they reproduced independent, ground-based measurements. They obtained their new estimate of the tropical carbon absorption from the models they determined to be the most trusted and verified. ...

Effect of increasing CO₂ on the terrestrial carbon cycle - David Schimel, Britton B. Stephens, Joshua B. Fisher

• Proceedings of the National Academy of Sciences (online 19 Nov 2014) DOI: 10.1073/pnas.1407302112

[BDanielMayfield]

It is good news that the Earth's ecosystems are capable of cleaning up the mess humankind as a whole is inflicting upon this unique planet. It's great that tropical forests are so good at absorbing CO₂, but much carbon in the tropics is being sent right back into the atmosphere by the widespead practice of slash and burn agriculture.

Bruce