Amazon forest more resilient to climate change than feared - study

OSLO Wed Feb 6, 2013 11:58pm IST

An aerial view shows illegal deforestation close to the Amazonia National Park in Itaituba, state of Para, May 25, 2012. REUTERS/Nacho Doce/Files

An aerial view shows illegal deforestation close to the Amazonia National Park in Itaituba, state of Para, May 25, 2012.

Credit: Reuters/Nacho Doce/Files

Related Topics

OSLO (Reuters) - The Amazon rainforest is less vulnerable to die off because of global warming than widely believed because the greenhouse gas carbon dioxide also acts as an airborne fertiliser, a study showed on Wednesday.

The boost to growth from CO2, the main gas from burning fossil fuels blamed for causing climate change, was likely to exceed damaging effects of rising temperatures this century such as drought, it said.

"I am no longer so worried about a catastrophic die-back due to CO2-induced climate change," Professor Peter Cox of the University of Exeter in England told Reuters of the study he led in the journal Nature. "In that sense it's good news."

Cox was also the main author of a much-quoted study in 2000 that projected that the Amazon rainforest might dry out from about 2050 and die off because of warming. Others have since suggested fires could transform much the forest into savannah.

Plants soak up carbon dioxide from the atmosphere and use it as an ingredient to grow leaves, branches and roots. Stored carbon gets released back to the atmosphere when plants rot or are burnt.

A retreat of the Amazon forests, releasing vast stores of carbon, could in turn aggravate global warming that is projected to cause more floods, more powerful storms and raise world sea levels by melting ice sheets.

"CO2 fertilisation will beat the negative effect of climate change so that forests will continue to accumulate carbon throughout the 21st century," Cox said of the findings with other British-based researchers.

ROOT AND BRANCH

The scientists said the study was a step forward because it used models comparing forest growth with variations in the rising levels of carbon dioxide in the atmosphere.

It estimated that the damaging effects of warming would cause the release of 53 billion tonnes of carbon stored in lands throughout the tropics, much of it in the Amazon, for every single degree Celsius (1.8F) of temperature rise.

The benefits of CO2 fertilisation exceeded those losses in most scenarios, which ranged up to a 319 billion tonne net gain of stored carbon over the 21st century. About 500 to 1,000 billion tonnes of carbon are stored in land in the tropics.

Climate change would be more damaging for the Amazon if greenhouse gases other than CO2, such as ozone or methane which do not have a fertilising effect, take a bigger role, the study said.

It did not factor in damaging effects from deforestation, mostly burning to clear land for farms, that is blamed for perhaps 17 percent of world greenhouse gas emissions from human activities.

Brazil has sharply reduced forest losses in recent years. But predictions of a die-back in coming decades had led some people to conclude that there was no point safeguarding trees.

"Some people argued bizarrely that it would be better to chop them down and use them now," Cox said, adding that the new findings meant that reasoning was no longer valid.

By underlining the importance of trees for soaking up CO2, the study could also bolster slow-paced efforts to create a market mechanism to reward nations for preserving tropical forests as part of U.N. negotiations on a new treaty to slow climate change, due to be agreed by the end of 2015.

(Editing by Robin Pomeroy)

FILED UNDER:
Comments (0)
This discussion is now closed. We welcome comments on our articles for a limited period after their publication.

  • Most Popular
  • Most Shared

UKRAINE CRISIS

REUTERS SHOWCASE

Pakistan Turmoil

Pakistan Turmoil

Pakistan parliament backs embattled prime minister as crisis deepens.  Full Article 

Gaza Conflict

Gaza Conflict

End of Gaza war doesn't translate into peace  Full Article 

Photo

Hamas vs Fatah

Hamas popularity surges as Palestinian rivalry flares  Full Article 

Scottish Independence

Scottish Independence

UK's fate in the balance as poll shows record support for Scottish independence  Full Article 

Syria Aid

Syria Aid

Record 4.1 million in Syria got food aid in August, U.N. says  Full Article 

NATO Deployment

NATO Deployment

Afghan turmoil threatens NATO's "mission accomplished" plans  Full Article 

Reuters India Mobile

Reuters India Mobile

Get the latest news on the go. Visit Reuters India on your mobile device.  Full Coverage