Featured Research

from universities, journals, and other organizations

Tropical Deforestation And Global Warming: Smithsonian Scientist Challenges Results Of Recent Study

Date:
February 14, 2003
Source:
Smithsonian Institution
Summary:
Late last year, Frédéric Achard and colleagues published a controversial article in which they contended that earlier estimates of worldwide tropical deforestation and atmospheric carbon emissions were too high. In the February 14 issue of Science, Philip Fearnside from the National Institute for Amazonian Research in Brazil, and William Laurance from the Smithsonian Tropical Research Institute in Panama argue that the Achard study contains serious flaws rendering its conclusions about greenhouse gases unreliable.

Late last year, Frédéric Achard and colleagues published a controversial article in which they contended that earlier estimates of worldwide tropical deforestation and atmospheric carbon emissions were too high. In the February 14 issue of Science, Philip Fearnside from the National Institute for Amazonian Research in Brazil, and William Laurance from the Smithsonian Tropical Research Institute in Panama argue that the Achard study contains serious flaws rendering its conclusions about greenhouse gases unreliable.

Related Articles


The article in question ("Determination of deforestation rates of the world's humid tropical forests", Science, vol. 297, pages 999-1002), which received extensive press coverage, asserted that only about 0.6 to 1.0 billion tons of greenhouse gases (most carbon dioxide and carbon monoxide) were being produced by the razing and felling of tropical forests each year. This estimate is considerably lower than those of earlier studies, which estimated up to 2.4 billion tons annually.

Fearnside and Laurance list seven serious errors or limitations of the Achard study, which, they say, collectively lead to a major underestimate of greenhouse gas emissions.

Among the errors they identify is that the Achard team failed to include drier tropical forests--which are also being rapidly cleared and burned--in their estimate. Other concerns include underestimating the amount of biomass--and hence the amount of carbon--contained in tropical forests. The study assumes that regenerating forests on abandoned lands will re-absorb large amounts of atmospheric carbon. In fact, such forests are often re-cleared after a few years. The study also fails to consider the effects of important greenhouse gases like methane and nitrous oxide, which are also produced by deforestation.

Fearnside and Laurance further assert that the effects on global warming of selective logging, habitat fragmentation, and other types of forest degradation are not included in the Achard study. Selective logging, for example, does not cause deforestation per se but produces hundreds of millions of tons of greenhouse gas emissions each year.

"When you look at all these factors, you can't help but conclude that their numbers are too small," said Laurance. "They're suggesting that tropical deforestation and degradation accounts for only about a tenth of the global production of greenhouse gases. Personally, I'd argue that their estimate is two to three times too low."

Each year, humans produce seven to eight billion tons of greenhouse gas emissions, which are considered the major cause of global warming. Most emissions are produced by the burning of fossil fuels and tropical deforestation, but the relative importance of these two sources remains controversial.


Story Source:

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


Cite This Page:

Smithsonian Institution. "Tropical Deforestation And Global Warming: Smithsonian Scientist Challenges Results Of Recent Study." ScienceDaily. ScienceDaily, 14 February 2003. <www.sciencedaily.com/releases/2003/02/030214074147.htm>.
Smithsonian Institution. (2003, February 14). Tropical Deforestation And Global Warming: Smithsonian Scientist Challenges Results Of Recent Study. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2003/02/030214074147.htm
Smithsonian Institution. "Tropical Deforestation And Global Warming: Smithsonian Scientist Challenges Results Of Recent Study." ScienceDaily. www.sciencedaily.com/releases/2003/02/030214074147.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) — The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Arctic Warming Twice As Fast As Rest Of Planet

Arctic Warming Twice As Fast As Rest Of Planet

Newsy (Dec. 18, 2014) — The Arctic is warming twice as fast as the rest of the planet, thanks in part to something called feedback. Video provided by Newsy
Powered by NewsLook.com
Prenatal Exposure To Pollution Might Increase Autism Risk

Prenatal Exposure To Pollution Might Increase Autism Risk

Newsy (Dec. 18, 2014) — Harvard researchers found children whose mothers were exposed to high pollution levels in the third trimester were twice as likely to develop autism. Video provided by Newsy
Powered by NewsLook.com
Ivory Trade Boom Swamps Law Efforts

Ivory Trade Boom Swamps Law Efforts

Reuters - Business Video Online (Dec. 17, 2014) — Demand for ivory has claimed the lives of tens of thousands of African elephants and now a conservation report says the illegal trade is overwhelming efforts to enforce the law. Amy Pollock 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