A recent end to a 30-year study published in the journal Science has provided the first concrete evidence that drought – even in moderate amounts – releases massive amounts of carbon dioxide
This results in the destruction of rainforests and acceleration of climate warming.
The study was an international collaboration of 68 scientists from 13 countries. Oliver Philips, the head researcher and tropical ecology professor from the University of Leeds, explained that the Amazon forest lends its hand in slowing down climate change. If the drought keeps up, however, carbon dioxide levels will rise even faster.
What does that mean for our environment? “Deeper cuts in emissions will be required to stabilize our climate,” Philips points out.
Normally, the rainforest absorbs approximately 2 billion tonnes of carbon dioxide. For the last 25 years or so, it has consistency absorbed about 1/5 of global fossil fuel emissions. However, scientists involved in the study used a significant drought in 2005 to their advantage. An unusual Amazon drought showed an exceptional warming, which gave them a sense of what could happen in the future if the ocean continues to warm as predicted, and more dry seasons appear. This drought reversed decades of previous carbon absorption.
Under the conventional circumstances, the drought caused additioanl carbon dioxide to release into the atmosphere – nearly 5 billion extra tonnes worth.
Their records, then, showed that tree death rates increased. “Because the region is so vast, even small ecological effects can scale-up to a large impact on the planet’s carbon cycle,” explained Professor Phillips. Some types of trees, like palm trees, were more vulnerable.
Because the Amazon accounts for more than half of the world’s rainforest, this was a significant finding. If repeated, Amazon droughts will accelerate climate warming and make future droughts even more damaging.
Source and image: Sciencedaily.com