Study - At 4C Rise, World's Forests Won't Absorb Any More Additional Atmospheric Carbon
A four-degree-Celsius rise in the Earth’s surface temperature could max out the amount of carbon dioxide that forests can trap from the atmosphere, according to new research by a team of European researchers.
Rainforests, such as the Amazon, act as natural carbon “sinks,” using up and storing carbon dioxide (CO2) from the air to make food. While humans continue to pump CO2 into the atmosphere, these sinks help maintain a balance by absorbing up to half of the total CO2 emitted globally.
The key factor that decides how Earth’s plants and forests will respond to higher carbon dioxide levels is how long CO2 remains trapped in the plants during its lifecycle – known as “residence time,” researchers report.
As CO2 content in the atmosphere increases, initially, forests will take up more CO2 and make more food. But as temperatures continue to rise, plants begin experiencing stress, lose their ability to retain water and CO2, and at one point, “flatline” – reaching a point where they can’t take up any more CO2.
EDIT
http://www.redorbit.com/news/science/1113031382/forests-carbon-dioxide-global-warming-climate-change-heat-sink-residence-time-121813/
