Wednesday, January 14, 2009

Analysis of increase in "skeptical" climate stories

There has been an uptick in media attention paid to the rantings of climate change "skeptics" and the faux notion of "global cooling".

And not only in the usual places like the Calgary Herald and Fox News. There have the been segments on CNN's Lou Dobbs Tonight, nicely deconstructed by Real Climate and Open Mind; the supposedly ironic sensibilities of Rex Murphy in the Globe and Mail and on CBC-Radio; a wildly errant story on the Huffington Post; a statistically-challenged meditation on sea ice in Daily Tech; and, last but by no means least, the drive-by mocking of Margaret Wente's year-end Globe and Mail column, which included by far the most erroneous claim that I've seen in some time: "Australia's magnificent coral reefs, once thought to have been devastated by the impact of global warming, have bounced back remarkably".

Is this recent spate of stories the sign of a long-term trend towards increased media coverage of climate change skepticism? Let's look at the data. Below I've plotted the fraction of media stories about climate change that can be classified as "skeptical" (i.e. questioning the role of human activities).

As you can see, there has been a trend since the 1970s towards increased positive coverage of the scientific evidence for a human contribution to climate change. Superimposed on this trend is year-to-year variability in the news coverage, caused by the chaotic and multi-factorial nature of the media. So if comparing a single year to the previous year, rather than considering the long-term trend, can result in an erroneous conclusion.

For example, if you draw a line from 1998, a low for skeptical reporting, to 2008, it may appear that skeptical reporting has been increasing and the world is trending towards an all Glenn Beck, all-the-time news media. In reality, this decade has featured less skeptical reporting in recorded history (records go back to the 1870s, but are less reliable before the 1930s due to limited coverage in some regions). The long-term trend suggest 2008 was an aberration, likely due to the La Nina conditions in the Pacific.

So everyone, keep fighting those mistakes in the media. But rest easy. The silliness won't last.


Anonymous said...

1/temperature anomaly? Looks like a trend to me! Amusing, and deep. Probably some will miss it. I nearly asked you for your data :)

I like your blog. I'll add it to my blogroll.. look forward to more.

Simon Donner said...

Not exactly 1/GISTEMP, but something like that. I'd love to see the real data on skeptical reporting.