Two degrees of climate change may be too much

Dawn Stover in Bulletin of the Atomic Scientists:

Touring Alaska this week to shine a spotlight on global warming, President Obama warned that “climate change is no longer some far-off problem. It is happening here; it is happening now. Climate change is already disrupting our agriculture and ecosystems, our water and food supplies, our energy, our infrastructure, human health, human safety. Now. Today.”

This wasn’t supposed to happen. In 2009, 114 countries signed the Copenhagen Accord, agreeing “to stabilize greenhouse gas concentration in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system;” “recognizing the scientific view” that the increase in global temperature should be held to no more than 2 degrees Celsius” (3.6 degrees Fahrenheit) above the pre-industrial level; and promising greater “long-term cooperative action to combat climate change.”

Paradoxically, an accord that should have spurred the world to immediate action instead seemed to offer some breathing room. Two degrees was meant to be a ceiling, but repeated references to an internationally agreed-upon “threshold” led many people to believe that nothing really bad could happen below 2 degrees—or worse yet, that the number itself was negotiable. Perhaps the biggest failure of the Copenhagen Accord was its pact for “long-term” action. Forty years ago, climate change was a “long-term” problem. Today it’s an emergency.

More here.