The future of the earth’s climate becomes more certain every day for two reasons. First, absent the leadership of the richest and most-polluting country, global levels of greenhouse gas emissions continue to rise at an alarming pace. This makes it more likely we will see the high end of current projections for both future greenhouse gas concentrations and climate impacts.
Second, almost every week we learn more about the dangerous positive feedbacks or vicious cycle in the climate system, whereby an initial warming causes changes that release more greenhouse gas emissions, which in turn causes more warming, and more emissions, and so on and on.
Perhaps the most dangerous vicious cycle is the melting of the Arctic permafrost, which contains more carbon locked away in frozen soil than the entire atmosphere holds today. Worse, thawed permafrost can release its carbon as methane, which is more than 20 times as potent a greenhouse gas as carbon dioxide.
New research finds that the Arctic contains far more carbon than previously thought (Science, subs. req’d) and that methane is bubbling up out of the tundra far faster than previously thought (Nature, subs. req’d). As the Associated Press put it, humans “may be triggering a self-perpetuating climate time bomb.”
We must all act to ensure that the President elected in 2008 has far more interest in stopping this time bomb than the current president who has none.