New study debunks myths about Amazon rain forests (potentially embarrassing for IPCC)

[OKIsItJustMe]

http://www.eurekalert.org/pub_releases/2010-03/bumc-nsd031110.php

Public release date: 11-Mar-2010

Contact: Richard Taffe
[e-mail]
617-353-4626
http://www.bu.edu/">Boston University

New study debunks myths about Amazon rain forests

They may be more tolerant of droughts than previously thought

(Boston) -- A new NASA-funded study has concluded that Amazon rain forests were remarkably unaffected in the face of once-in-a-century drought in 2005, neither dying nor thriving, contrary to a previously published report and claims by the Intergovernmental Panel on Climate Change.

"We found no big differences in the greenness level of these forests between drought and non-drought years, which suggests that these forests may be more tolerant of droughts than we previously thought," said Arindam Samanta, the study's lead author from Boston University.

The comprehensive study published in the current issue of the scientific journal Geophysical Research Letters used the latest version of the NASA MODIS satellite data to measure the greenness of these vast pristine forests over the past decade.

A study published in the journal Science in 2007 claimed that these forests actually thrive from drought because of more sunshine under cloud-less skies typical of drought conditions. The new study found that those results were flawed and not reproducible.

"This new study brings some clarity to our muddled understanding of how these forests, with their rich source of biodiversity, would fare in the future in the face of twin pressures from logging and changing climate," said Boston University Prof. Ranga Myneni, senior author of the new study.

The IPCC is under scrutiny for various data inaccuracies, including its claim – based on a flawed World Wildlife Fund study -- that up to 40% of the Amazonian forests could react drastically and be replaced by savannas from even a slight reduction in rainfall.

"Our results certainly do not indicate such extreme sensitivity to reductions in rainfall," said Sangram Ganguly, an author on the new study, from the Bay Area Environmental Research Institute affiliated with NASA Ames Research Center in California.

"The way that the WWF report calculated this 40% was totally wrong, while (the new) calculations are by far more reliable and correct," said Dr. Jose Marengo, a Brazilian National Institute for Space Research climate scientist and member of the IPCC.

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Geophysical Research Letters article citation: Samanta, A., S. Ganguly, H. Hashimoto, S. Devadiga, E. Vermote, Y. Knyazikhin, R. R. Nemani, and R. B. Myneni (2010), Amazon forests did not green‐up during the 2005 drought, Geophys. Res. Lett., 37, L05401, doi:10.1029/2009GL042154.

[Birthmark]

1. What myth?

"...which suggests that these forests may be more tolerant of droughts than we previously thought," said Arindam Samanta, the study's lead author from Boston University."

And how is it embarrassing to the IPCC? The IPCC used the available information --which is their job. Being omniscient ISN'T their job. That's just what denialists want the public to believe. ;)

[eppur_se_muova]

2. WAAAAAY overly dramatized headline.

Different models predict different outcomes, differing by degree, which may have more dramatic localized effects in some areas. This is not quite the either/or dichotomy the headline writer wants to imply.

If it turns out the rain forest is in somewhat less danger than we thought, that is not "debunking". It's only a more accurate prediction. And since the rainforest/savannah question is only one part of the whole GW issue, it should not be taken as a rebuke of warnings re. GW.

[OKIsItJustMe]

3. I think an important point is being missed here.

(It's my fault for parenthetically adding the note about the IPCC. My point was that this will probably be another thing the IPCC will be attacked for. Yes, it will be an unfair attack, but...)

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This study refutes two myths.

One myth predicts that a slight warming will bring a dramatic result.

...

"Our results certainly do not indicate such extreme sensitivity to reductions in rainfall," said Sangram Ganguly, an author on the new study, from the Bay Area Environmental Research Institute affiliated with NASA Ames Research Center in California.

...

The other myth is that drought is good for the forest.

...

A study published in the journal Science in 2007 claimed that these forests actually thrive from drought because of more sunshine under cloud-less skies typical of drought conditions. The new study found that those results were flawed and not reproducible.

...

[OKIsItJustMe]

4. Here we go! - That didn't take long.

http://www.telegraph.co.uk/earth/environment/climatechange/7437016/UN-climate-change-claims-on-rainforests-were-wrong-study-suggests.html

UN climate change claims on rainforests were wrong, study suggests

The United Nations' climate change panel is facing fresh criticism after new research contradicted the organisation's claims about the devastating effect climate change could have on the Amazon rainforest.

By Richard Gray, Science Correspondent
Published: 9:00PM GMT 13 Mar 2010

A new study, funded by Nasa, has found that the most serious drought in the Amazon for more than a century had little impact on the rainforest's vegetation.

The findings appear to disprove claims by the Intergovernmental Panel on Climate Change (IPCC) that up to 40% of the Amazon rainforest could react drastically to even a small reduction in rainfall and could see the trees replaced by tropical grassland.

The IPCC has already faced intense criticism for using a report by environmental lobby group WWF as the basis for its claim, which in turn had failed to cite the original source of the research.

Scientists have now spoken out against the 40% figure contained in the IPCC report and say that recent research is suggesting that the rainforest may be more resilient to climate change than had been previously thought.

...