A mixed bag in climate change news this morning: Satellite imagery reveals that Amazon deforestation has dropped to the lowest rate since Brazil began monitoring efforts, President Inácio Lula da Silva announced yesterday afternoon. Woo hoo! But a new article in the journal Science shows that the Greenland Ice Sheet is losing mass an accelerating rate. D'oh!
Seven Meters of Sea Level Rise if Greenland Ice Sheet Melts
The Greenland observation was independently confirmed by two sources, satellite observation as well as a state-of-the-art regional atmospheric model.
This mass loss is equally distributed between increased iceberg production, driven by acceleration of Greenland's fast-flowing outlet glaciers, and increased meltwater production at the ice sheet surface. Recent warm summers further accelerated the mass loss to 273 Gt per year (1 Gt is the mass of 1 cubic kilometre of water), in the period 2006-2008, which represents 0.75 mm of global sea level rise per year. (Science Codex)
Remember that if the whole of the Greenland Ice Sheet melts, there's enough water contained within it to cause seven meters of sea level rise. Since 2000, this melting has contributed in total 5mm, so not a huge effect yet -- but this is the biggie; maybe not this century, but if current emission levels continue upward, certainly in the future.
Deforestation Hits Lowest Levels Since 1988
The much better news is that from August 2008 to July 2009, deforestation in the Brazilian Amazon dropped 45.7%, according to data from Brazil's National Institute for Space Research (abbreviated INPE in Portuguese) -- slightly over 7,000 square kilometers were cleared in that time period, the lowest level since monitoring began two decades ago.
Brazil is attributing the decline in deforestation to its Action Plan for Deforestation Control and Prevention in the Amazon program (PPCDAM is probably easier...). The program, launched in 2004, increased the use of satellite monitoring; increased law enforcement inspection operations by 32%; established environmental criteria as pre-requisites for loans for farmers and ranchers; and, increased the land under federal and state protection by 50 million hectares.
If that sounds familiar, it's because similar data was trotted out by Brazil a few months back. This latest announcement seems to confirm earlier reports, and extends the record low from 2004, back to 1998. PR spin or scientific adjustment?
Source:treehugger.com/
No comments:
Post a Comment