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 Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

nachricht Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

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: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>