Making Mountains Out of Glaciers

Yesterday, we talked about John Coleman and his sorry excuse for a climate change lesson. As a reader pointed out to me, one piece of evidence in particular has generated another climate news scandal recently. As a refresher:

according to the National Snow and Ice Data Center, global glacier thickness has declined every year for the past 4+ decades. The most recent academic research I’ve seen was published 2 months ago, and it concluded that Antarctic ice loss has been vaster and faster than the IPCC predicted. Another paper published around the same time found that, based on historical evidence, Antarctica is more sensitive to greenhouse gases than previously thought.

When many people hear “glaciers,” they think of the Himalayas. One of the most startling predictions of the 2007 IPCC report was that this gorgeous region in South and East Asia will lose all its glaciers by 2035. If you trace that claim back to its original source, you find quotes in New Scientist and Indian magazine Down to Earth by Syed Hasnain, who studied the Himalayan glaciers for the International Commission on Snow and Ice. Hasnain, it turns out, made the prediction based on “speculation,” not evidence.

Let’s be clear about what this means: Nothing.  

Okay, it means something, but not nearly as much as the media might lead you to believe. It was a blunder, to be sure, and it requires an apology, a correction, and a full review of all melting ice and sea level rise predictions in the report. To its credit, the IPCC is not covering it up; it made an immediate public retraction.

Here’s what does matter, if you’re trying to form an opinion about climate change:

1. The Himalaya prediction was not based on evidence. All three of the research conclusions I cited yesterday (above) about ice melt are based on hard evidence: glacier thickness measurements and Antarctic ice measurements. All are facts about what happened, not predictions about what will happen.

2. One region does not represent global trends. To make that mistake is to fall prey to “selection bias,” which we talked about a couple days ago, or similarly, “small sample bias.” Statistical no-nos.

3. Courtesy of climate expert Joseph Romm, here is the latest evidence-based research:

4. Just because the prediction is wrong doesn’t mean the trend is. The Himalaya glaciers may not disappear by 2035—and thank goodness for that—but they are melting, and if that trend doesn’t stop…well, they will disappear eventually.