Tue Feb 5th, 2013 at 07:50:59 AM EST
At the New York Times, journalist Andrew Revkin provides a comprehensive run-down of current scientific thinking on a crucial aspect of a warming climate – the sensitivity of the planet to increasing greenhouse gasses.
A Closer Look at Moderating Views of Climate Sensitivity - NYTimes.com
There’s still plenty of global warming and centuries of coastal retreats in the pipeline, so this is hardly a “benign” situation, as some have cast it.
But while plenty of other climate scientists hold firm to the idea that the full range of possible outcomes, including a disruptively dangerous warming of more than 4.5 degrees C. (8 degrees F.), remain in play, it’s getting harder to see why the high-end projections are given much weight.
This is also not a “single-study syndrome” situation, where one outlier research paper is used to cast doubt on a bigger body of work — as Skeptical Science asserted over the weekend. That post focused on the as-yet-unpublished paper finding lower sensitivity that was inadvisedly promoted recently by the Research Council of Norway.
In fact, there is an accumulating body of reviewed, published research shaving away the high end of the range of possible warming estimates from doubled carbon dioxide levels.
After years of reports in the media that doubling the amount of greenhouse gasses in the earth's atmosphere could see temperatures creeping up to more than a worrying three (IPCC, here), a frightening six (2007, here) or even an apocalyptic eight degrees Celsius (2013, here), now a stack of science findings that show lesser extremes is beginning to find its way.
Previously, media presentation on climate sensitivity have predictably focussed on the high and sensational end of the computed ranges – but plenty of scientists have actively played the part to toot around scary numbers. Just see the last example.
Findings listed by Revkin are not even particular new; some have been around for years. But the topic is controversial and will likely remain that for a while. Before media start writing on a revision of what they've been writing for years, it needs a bit of weight behind it. It now seems we've reached a first turning point.
Of course, even when the implications of earth's lower sensitivity are huge, it doesn't mean we're out of the woods. It doesn't mean either that the earth is practically insensitive to increasing carbon, which is how the sceptical crowds frame the discussion. It does mean that the earth destroying scare scenarios have lost ground – yet again.