Sunday, August 1, 2010
Is AGW causing a Decline in Phytoplankton?
There is a recent article in Nature that reports a 40% decline in the amount of phytoplankton in the ocean over the past century. Here's a good summary of the paper. If this is true, it's very disturbing news. Phytoplankton is a vital part of the food chain, and also plays an important role in the carbon cycle by absorbing carbon dioxide from the atmosphere. The authors speculate that global warming has caused the declining numbers by increasing the stratification of the ocean, which in turn reduces circulation and decreases the amount of nutrients that reach the plankton from deeper layers. There may be other causes as well. Clearly, more study is needed to confirm the trend and it's causes. But if phytoplankton numbers are indeed falling, could this trigger one of those dreaded "climate feedback loops" that we keep reading about?