The Lesson of the 2005 Amazonian Drought

This could be the most startling story I've read in awhile. The above picture shows one of the tributaries of the Amazon River that completely dried up during the 2005 drought, leaving a ferry boat beached on the riverbed. I had no idea the drought even happened...

By studying the effects of the drought, the Amazons' worst in a century, scientists have released some very sobering news:

"The world’s forests are an enormous carbon sink, meaning they absorb massive quantities of carbon dioxide, through the processes of photosynthesis and respiration. In normal years the Amazon alone absorbs three billion tons of carbon, more than twice the quantity human beings produce by burning fossil fuels. But during the 2005 drought, this process was reversed, and the Amazon gave off two billion tons of carbon instead, creating an additional five billion tons of heat-trapping gases in the atmosphere. That’s more than the total annual emissions of Europe and Japan combined."

"Significantly, Phillips also found that the 2005 drought was not the result of El Niño, the cause of previous smaller episodes, but of a regional rise in sea temperatures—one of the expected early signs of global warming. Taken together, these findings suggest that climate change could trigger the worst kind of vicious cycle, with climbing temperatures causing the rainforests to dry out and give off massive quantities of greenhouse gases, which in turn causes the planet to warm more rapidly—a dynamic with harrowing implications. An article last year in Proceedings of the National Academy of Science identified rainforest-wide dieback in the Amazon, along with the melting of the Arctic sea ice, as among the nine most crucial "tipping points" that must be staved off to prevent catastrophic climate change.

As if that’s not enough bad news, new research presented in March at a conference organized by the University of Copenhagen, with the support of the Intergovernmental Panel on Climate Change, says that as much as 85 percent of the Amazon forests will be lost if the temperature in the region increases by just 7.2 degrees Fahrenheit. To keep from hitting that mark, we will have to curb global carbon emissions by at least 80 percent. At the same meeting, Vicky Pope, a researcher from Britain’s Met Office (a government agency that tracks climate and weather data) showed that a temperature increase of 2.2 degrees above current levels would trigger a 20 to 40 percent Amazon die-off within 100 years. A rise of 5.4 degrees would kill 75 percent of the trees. "The forest as we know it would effectively be gone," she says. Other Met researchers have found that the loss of the forest would be irreversible. "

The good news is that at the most recent G-8 meeting in Italy last week, each of the 8 nations agreed to cut their greenhouse gas emissions 80% by 2050. However, none of them could agree on any short-term goals. It'll be interesting to see how this all plays out at the major meeting on climate change in Copenhagen later this year.