December 29, 2006

Year 2006: The State of the Environment

The Independent has a sobering wrap up of the Year 2006's Global Warming news today. One thing evident from the year's scientific publications is that we might not be worried enough about global warming because as Steve Connor puts it, the big story of the year is feedback and how that affects the earth's natural systems.

During the past year, scientific findings emerged that made even the most doom-laden predictions about climate change seem a little on the optimistic side. And at the heart of the issue is the idea of climate feedbacks - when the effects of global warming begin to feed into the causes of global warming. Feedbacks can either make things better, or they can make things worse. The trouble is, everywhere scientists looked in 2006, they encountered feedbacks that will make things worse - a lot worse.

Next year, the UN's Intergovernmental Panel on Climate Change (IPCC) will publish its fourth assessment on the scale of the future problems facing humanity. Its last assessment, published in 2001, had little to say on the subject of climate feedbacks, partly because, at that time, they were such an unknown quantity. This year, scientists came to learn a little more about them, and they didn't like what they learnt.

During the past two decades, the IPCC has tended to regard the Earth's climate as something that will change gradually and smoothly, as carbon dioxide and global temperatures continue their lock-step rise. But there is a growing consensus among many climate scientists that this may be giving a false sense of security. They fear that feedback reactions may begin to kick in and suddenly tip the climate beyond a critical threshold from which it cannot easily recover.

Climate feedbacks could turn the Earth into a very different planet over a dramatically short period of time. It has happened in the past, scientists say, and it could easily happen in the future given the unprecedented scale of the environmental changes caused by man.

The story covers four different areas where the feedback loop is worrying:

  • the disappearing Arctic ice providing more open ocean which leads to more absorption of heat from the sun leading to more melting of the ice
  • increased melting of the permafrost in Siberia leading to increased release of the methane gas (a greenhouse gas thought to be ten times worse than carbon dioxide) trapped in the permafrost
  • a suspicion that planet Earth which so far has operated as a carbon dioxide sink (absorbing more than it is emitting) could turn into a carbon source due to increased organic decay
  • the disappearing plankton that once helped absorb the extra carbon emitted by man.

This year we've come to know that these problems are worse than we once realized.

James Hansen said that we had at most a decade to make some significant changes to our carbon emissions before it was too late. With the results of this year's studies, it looks like we better get hopping if we want a world in the future in which humans can survive.

Posted by Mary at December 29, 2006 11:31 PM | Environment | Technorati links |

"a greenhouse gas thought to be ten times worse than carbon dioxide"?

It's not "thought" to be ten times worse -- it's a fact of chemistry that its global warming potential is 62 times that of CO2 over a 20 year horizon and 23 times CO2 for 100 years (because methane leaves the atmosphere more rapidly than CO2).

The scary thing is that if the atmospheric concentration of methane reaches a tipping point, then its atmospheric lifetime dramatically increases.

Posted by: The Cunctator at December 31, 2006 03:04 PM

Thanks, Cunctator. Just yesterday I had read a piece saying that methane gas was 23 times worse than carbon dioxide, but it hadn't gotten into the detail you did. It certainly is a daunting problem we face. As I learn more, I find that I worry more about what is coming....

Posted by: Mary at December 31, 2006 10:58 PM

Above is a link to a piece in Orion Magazine about the actual scope of activity needed to move past the fossil fuel model. It could keep a lot of people busy for a while, create wealth and get us out of the looming mess.

Posted by: Chris Rich at January 1, 2007 09:48 AM