Featured Research

from universities, journals, and other organizations

Global Warming Aided By Drought, Deforestation Link

Date:
December 9, 2008
Source:
University of California - Irvine
Summary:
In the rainforests of equatorial Asia, a link between drought and deforestation is fueling global warming, finds an international study.

Deforestation fire.
Credit: Image courtesy of University of California - Irvine

In the rainforests of equatorial Asia, a link between drought and deforestation is fueling global warming, finds an international study that includes a UC Irvine scientist.

The study, analyzing six years of climate and fire observations from satellites, shows that in dry years, the practice of using fire to clear forests and remove organic soil increases substantially, releasing huge amounts of climate-warming carbon dioxide into the atmosphere.

In 2006, the climate on the fast-developing islands of Borneo and Sumatra and in New Guinea and other parts of equatorial Asia was three times drier than in 2000, but carbon emissions from deforestation were 30 times greater – exceeding emissions from fossil fuel burning.

"Land managers respond to the drought by using fire to clear more land. In dry years, they burn deeper into the forest, which in turn releases more carbon dioxide," said James Randerson, climate scientist at UCI and co-author of the study, published online the week of Dec. 8 in the Proceedings of the National Academy of Sciences.

The findings, Randerson says, illustrate why limits on deforestation should be a critical part of future climate agreements. Global warming modelers typically consider climate and land use separately when assessing how changes will affect greenhouse gas emissions.

The results also indicate that forecasting drought may be important when countries in this region allocate resources to combat illegally set fires and clearing.

"The link between drought and deforestation is very sensitive," Randerson said. "If the climate warms and there are more droughts, it potentially makes the forest and its stored carbon more vulnerable."

Equatorial Asia is a hot spot for biodiversity but is undergoing widespread changes. Its global markets are growing, as is large-scale agricultural business. Forests and peatlands in the region store tremendous amounts of carbon, keeping it out of the atmosphere where it can turn into carbon dioxide and create warming.

The climate in equatorial Asia changes substantially from year to year and is linked with El Nino. Dry years occurred in 2002 and 2006; wet years in 2000 and 2005.

In a dry climate, fires are easier to set and burn more deeply into organic soil. "When there is a lot of rainfall, fires don't burn as well, and it is more challenging to remove debris from areas that are being converted to agriculture," said Randerson, associate professor of Earth system science.

Randerson and his colleagues used several kinds of satellite data to develop and refine their emission estimates. First, they used satellite images of fire areas and additional information about carbon pools to estimate emissions from the region. Next, they sharpened their estimate using measurements of atmospheric carbon monoxide levels, which can be a strong signal of fire activity. In a final step, they used both carbon monoxide and satellite data to determine total carbon emissions.

"Deforestation and carbon emissions are substantial and important contributors to the buildup of greenhouse gases in the atmosphere," Randerson said. "We should not neglect this flux in developing comprehensive approaches for stabilizing climate."

In addition to Randerson, scientists who collaborated on the study include G.R. van der Werf and A.J. Dolman of VU University Amsterdam; J. Dempewolf and D.C. Morton of the University of Maryland; S.N. Trigg of Cranfield University in the United Kingdom; P.S. Kasibhatla of Duke University; L. Giglio of Science Systems and Applications, Inc.; D. Murdiyarso of the Center for International Forestry Research in Indonesia; W. Peters of Wageningen University and Research Center in the Netherlands; G.J. Collatz of NASA Goddard Space Flight Center; and R.S. DeFries of Columbia University.

This work was supported by NASA and the Netherlands Organization for Scientific Research.


Story Source:

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


Cite This Page:

University of California - Irvine. "Global Warming Aided By Drought, Deforestation Link." ScienceDaily. ScienceDaily, 9 December 2008. <www.sciencedaily.com/releases/2008/12/081208180339.htm>.
University of California - Irvine. (2008, December 9). Global Warming Aided By Drought, Deforestation Link. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2008/12/081208180339.htm
University of California - Irvine. "Global Warming Aided By Drought, Deforestation Link." ScienceDaily. www.sciencedaily.com/releases/2008/12/081208180339.htm (accessed April 18, 2014).

Share This



More Earth & Climate News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com
Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
How Mt. Everest Helped Scientists Research Diabetes

How Mt. Everest Helped Scientists Research Diabetes

Newsy (Apr. 15, 2014) British researchers were able to use Mount Everest's low altitudes to study insulin resistance. They hope to find ways to treat diabetes. Video provided by Newsy
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:
from the past week

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