A new NASA funded study 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 previously published prominent reports and IPCC claims.
This 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. “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, USA.
This new study comes at a time when the Intergovernmental Panel on Climate Change (IPCC) is under review by the World’s Academies for various inaccuracies, including the so-called Amazongate - a reference to its claim 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 this study, from the Bay Area Environmental Research Institute affiliated with NASA Ames Research Center in California.
The IPCC based its statements on a flawed World Wildlife Fund (WWF) study – “The way that the WWF report calculated this 40% was totally wrong, while your
calculations are by far more reliable and correct” said Dr. Jose Marengo, a climate scientist at the Brazilian National Institute for Space Research and a member of the IPCC.
More provocatively, a previous study published in the prestigious American journal “Science” in 2007 claimed that not only are these forests insensitive to droughts but they actually thrive because of more sunshine under cloud-less skies typical of drought conditions. The current study found that those results were flawed and not reproducible. “We actually submitted our evidence to the Editors at Science, but they decided not to seek peer-review, perhaps afraid of a controversy given all the hoopla surrounding IPCC” said Ranga Myneni, the senior author from Boston University.
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.
Arindam Samanta (arindam.sam@
Sangram Ganguly (sangramganguly@
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/