Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tropical deforestation and global warming

14.02.2003


Smithsonian scientist challenges results of recent study



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.
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.



For further information:
William F. Laurance
Smithsonian Tropical Research Institute
Balboa, Panama
Phone: 507-314-9206 and 507-212-8252
Email: laurancew@tivoli.si.edu

Philip M. Fearnside
National Institute for Amazonian Research
Manaus, Brazil
Phone: 55-92-642-8913 and 55-92-643-1822
Email: pmfearn@inpa.gov.br

Researchers at the Smithsonian Tropical Research Institute, with headquarters in Panama City, Panama, study the past, present and future of tropical biodiversity and its implications for humankind.

Dr. Bill Laurance | EurekAlert!
Further information:
http://www.si.edu/

More articles from Ecology, The Environment and Conservation:

nachricht Loss of habitat causes double damage to species richness
02.04.2019 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Deep decarbonization of industry is possible with innovations
25.03.2019 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter

  • Coolest and smallest star to produce a superflare found
  • Star is a tenth of the radius of our Sun
  • Researchers led by University of Warwick could only see...

Im Focus: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

Im Focus: Largest, fastest array of microscopic 'traffic cops' for optical communications

The technology could revolutionize how information travels through data centers and artificial intelligence networks

Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...

Im Focus: A long-distance relationship in femtoseconds

Physicists observe how electron-hole pairs drift apart at ultrafast speed, but still remain strongly bound.

Modern electronics relies on ultrafast charge motion on ever shorter length scales. Physicists from Regensburg and Gothenburg have now succeeded in resolving a...

Im Focus: Researchers 3D print metamaterials with novel optical properties

Engineers create novel optical devices, including a moth eye-inspired omnidirectional microwave antenna

A team of engineers at Tufts University has developed a series of 3D printed metamaterials with unique microwave or optical properties that go beyond what is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

 
Latest News

New automated biological-sample analysis systems to accelerate disease detection

18.04.2019 | Life Sciences

Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

18.04.2019 | Physics and Astronomy

New eDNA technology used to quickly assess coral reefs

18.04.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>