Featured Research

from universities, journals, and other organizations

Lungs of the planet reveal their true sensitivity to global warming

Date:
February 6, 2013
Source:
University of Exeter
Summary:
The amount of carbon dioxide that rainforests absorb, or produce, varies hugely with year-to-year variations in the climate. Climate scientists have shown that these variations reveal how vulnerable the rainforest is to climate change.

Tropical rainforests are often called the "lungs of the planet" because they generally draw in carbon dioxide and breathe out oxygen. But the amount of carbon dioxide that rainforests absorb, or produce, varies hugely with year-to-year variations in the climate.
Credit: © Stιphane Bidouze / Fotolia

Tropical rainforests are often called the "lungs of the planet" because they generally draw in carbon dioxide and breathe out oxygen. But the amount of carbon dioxide that rainforests absorb, or produce, varies hugely with year-to-year variations in the climate. In a paper published online Feb 6 2013 by the journal Nature, a team of climate scientists from the University of Exeter, the Met Office-Hadley Centre and the NERC Centre for Ecology & Hydrology, has shown that these variations reveal how vulnerable the rainforest is to climate change.

Related Articles


Lead author Professor Peter Cox of the University of Exeter explained: "We have been struggling for more than a decade to answer the question 'will the Amazon forest die back under climate change?' Our study indicates that the risk is low if climate change is associated with increased plant growth under elevated carbon dioxide. But if this effect declines, or climate warming occurs due to something other than a carbon dioxide increase, we expect to see a significant release of carbon from tropical ecosystems."

The study reveals a new way to find out how sensitive biological systems are to changes in climate. The key was to learn how to read the year-to-year variations in the concentration of carbon dioxide in the atmosphere. Carbon dioxide increases each year as a result of burning fossil fuels and deforestation. But the amount it goes up from one year to the next depends on whether tropical forests are absorbing carbon dioxide or releasing it -- and this in turn depends on whether the tropical climate was warmer and dryer than usual, or wetter and cooler. So the trace of carbon dioxide in the atmosphere holds a record of how the lungs of the planet respond when the climate warms or cools.

The team studied how these year-to-year variations in carbon dioxide concentration relate to long-term changes in the amount of carbon stored in tropical rainforests. They found that climate models that predicted tropical forest dieback under climate change also had a very large year-to-year variation in carbon dioxide concentration, while models in which the rainforest was more robust to climate change had more realistic year-to-year variation in carbon dioxide concentration.

By combining this relationship with the year-to-year variation in carbon dioxide as seen in the real world, the team were able to determine that about 50 billion tonnes of carbon would be released for each degree Celsius of warming in the tropics. Peter Cox said the findings were initially a relief: "Fortunately, this carbon release is counteracted by the positive effects of carbon dioxide fertilisation on plant growth under most scenarios of the 21st century, so that overall forests are expected to continue to accumulate carbon."

The researchers are however certain that tropical forests will suffer under climate change if carbon dioxide doesn't fertilise tree growth as strongly as climate models suggest.

Co-author, Chris Jones, of the Met Office said: "The long-term health of tropical forests will depend on their ability to withstand multiple pressures from changing climate and deforestation. Our research has shed light on the former, but the latter remains a significant pressure on this ecosystem."


Story Source:

The above story is based on materials provided by University of Exeter. Note: Materials may be edited for content and length.


Journal Reference:

  1. Peter M. Cox, David Pearson, Ben B. Booth, Pierre Friedlingstein, Chris Huntingford, Chris D. Jones, Catherine M. Luke. Sensitivity of tropical carbon to climate change constrained by carbon dioxide variability. Nature, 2013; DOI: 10.1038/nature11882

Cite This Page:

University of Exeter. "Lungs of the planet reveal their true sensitivity to global warming." ScienceDaily. ScienceDaily, 6 February 2013. <www.sciencedaily.com/releases/2013/02/130206131050.htm>.
University of Exeter. (2013, February 6). Lungs of the planet reveal their true sensitivity to global warming. ScienceDaily. Retrieved March 28, 2015 from www.sciencedaily.com/releases/2013/02/130206131050.htm
University of Exeter. "Lungs of the planet reveal their true sensitivity to global warming." ScienceDaily. www.sciencedaily.com/releases/2013/02/130206131050.htm (accessed March 28, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Saturday, March 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Antarctic Ice Is Melting Faster Than Ever

Antarctic Ice Is Melting Faster Than Ever

Newsy (Mar. 27, 2015) — A new study of nearly two decades of satellite data shows Antarctic ice shelves are losing more mass faster every year. Video provided by Newsy
Powered by NewsLook.com
Raw: Homes Near Landslide in Washington

Raw: Homes Near Landslide in Washington

AP (Mar. 27, 2015) — Aerial footage from KOMO shows several homes near a landslide in Washington. KOMO reports that at least one of the homes has been damaged. (March 27) Video provided by AP
Powered by NewsLook.com
Clean-Up Follows Deadly Weather in Okla.

Clean-Up Follows Deadly Weather in Okla.

AP (Mar. 26, 2015) — Gov. Mary Fallin has declared a state of emergency for 25 Oklahoma counties after powerful storms rumbled across the state causing one death, numerous injuries and widespread damage. (March 26) Video provided by AP
Powered by NewsLook.com
At Least Four Dead After Floods in Northern Chile

At Least Four Dead After Floods in Northern Chile

Reuters - News Video Online (Mar. 26, 2015) — At least four people have been killed by severe flooding in northern Chile after rains battered the Andes mountains and swept into communities below. Rob Muir reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins