Tripping Over Global Warming Tipping Points

Don at Article 19 linked to this story from Britain's Independent earlier this week, and if anybody else is talking about it, I've yet to see it. (The Independent link is a pay link now, but you can still read the story at truthout). The latest trend in global warming research is concern about "tipping points" that we may reach, at which point too much damage will have been done to the environment to prevent at least some of the affects of global warming. There are three main "tipping points" scientists are concerned about:

widespread coral bleaching that could damage the world's fisheries within three decades; dramatic sea level rise by the end of the century that would take tens of thousands of years to reverse; and, within 200 years, a shutdown of the ocean current that moderates temperatures in northern Europe.

According to an investigation by The Independent, we've already passed a tipping point on the way to one of those tipping points. The Independent article is poorly written and takes effort to work through (which probably accounts for why it hasn't received more attention), but the gist of it is that, at a British government conference held last hear, "Avoiding Dangerous Climate Change," scientists warned of reaching a dangerous level of greenhouse gasses in the atmosphere that would guarantee higher temperatures, which would in turn trigger a domino effect for further global warming. The level of greenhouse gasses (a combination of carbon dioxide, methane, nitrous oxide, and other similar gasses) necessary to kick all this off was estimated at the conference to be 400 parts per million. The Independent commissioned the head of meteorology at the University of Reading to determine the current level of these gasses. He found the current CO2 concentration to be 425 parts per million. Scientists cited in the article believe this puts us on track to see an average temperature rise of 2 degrees, which in turn would lead to the coral bleaching noted above as a firmer "turning point."

This is complicated and still somewhat speculative when it comes to details, but the Independent story suggests that we're on our way to the tipping points for this planet, and at some time, which we'll probably only recognize in hindsight, we'll pass a point of no return, from which the climate cannot recover.