Scientists are out in the field trying to gain a better understanding of how trees and forests respond to changes in climate. And they are using that knowledge to devise more sophisticated computer projections that narrow the range of possible outcomes.

One of the scarier possibilities to emerge from this body of work is worth dwelling on a bit, simply because it would be so devastating if it came to pass: the so-called Amazon dieback scenario. Many scientists were deeply skeptical of the idea when it was first published, but events in the last few years have made them less dismissive.

The scenario emerged most clearly in computer analyses in Britain led by Peter M. Cox of the University of Exeter and published in 2000 as a paper in the journal Nature. Running a large-scale computer simulation in which forests interacted with a changing global climate through the course of the 21st century, the Cox group found that forests would continue to take up carbon until about 2050.

But then, their computer predicted, warmer temperatures and water stress would cause a huge dieback of the Amazon forest, which would stop absorbing carbon and start emitting it as a result.

Scientists are out in the field trying to gain a better understanding of how trees and forests respond to changes in climate. And they are using that knowledge to devise more sophisticated computer projections that narrow the range of possible outcomes.

One of the scarier possibilities to emerge from this body of work is worth dwelling on a bit, simply because it would be so devastating if it came to pass: the so-called Amazon dieback scenario. Many scientists were deeply skeptical of the idea when it was first published, but events in the last few years have made them less dismissive.

The scenario emerged most clearly in computer analyses in Britain led by Peter M. Cox of the University of Exeter and published in 2000 as a paper in the journal Nature. Running a large-scale computer simulation in which forests interacted with a changing global climate through the course of the 21st century, the Cox group found that forests would continue to take up carbon until about 2050.

But then, their computer predicted, warmer temperatures and water stress would cause a huge dieback of the Amazon forest, which would stop absorbing carbon and start emitting it as a result.