A factoid is rapidly making the rounds in climate skeptic circles. By a factoid, I mean “A piece of unverified or inaccurate information that is presented to the press as factual . . . and that is then accepted as true because of frequent repetition.”

On the BBC program HARDtalk, reporter Stephen Sackur, in a combative interview with Gerd Leipold, retiring Executive Director of Greenpeace, accused Greenpeace of peddling exaggeration and alarmism about global warming. I think that’s true, but Sackur, however unwittingly, built his case on false evidence. And now the unfounded claim that Leipold confessed to misleading the public is making the rounds at skeptical blog sites and conservative newspapers.

Sackur cited a July 15 press release in which Greenpeace warns that, because of global warming, ”we are looking at ice-free summers in the Arctic as early as 2030.”

Sackur pounced on this statement, pointing out that ”the Arctic” includes the Greenland Ice Sheet, which is 1.6 million square kilometers in area, is 3 kilometers thick in the middle, and has survived previous warm periods over hundreds of thousands of years. “There is no way that ice sheet is going to disappear” in 20 or 30 years, he said.

Indeed, according to the self-anointed “consensus of scientists,” the UN Intergovernmental Panel on Climate Change (IPCC), it would take four times the pre-industrial level of carbon dioxide (CO2) — roughly 1100 parts per million (today it’s about 387 ppm) — sustained over 3,000 years to melt all of Greenland’s ice. See the figure below, which comes from Ridley et al. (2005), reviewed in Chapter 10 of the IPCC’s Fourth Assessment Report (p. 830).

Pressed by Sackur, Leipold said he did not think the Greenland Ice Sheet “would be melting by 2030.” Leipold allowed that “there may have been a mistake” in the press release, “although,” he added, ”I don’t know this specific press release, I do not check every press release.”

Some skeptics were quick to spin this exchange as a confession of error or even dishonesty by Greenpeace’s leader. It is not. First, Leipold said he did not recall the press release at issue, so he neither affirmed nor denied that it said what Sackur says it said. Second, and more importantly, Sackur took the sentence he quoted out of context.

Anyone who actually reads the press release, especially in conjunction with the NASA study to which it is linked, can see immediately that the warning of ice-free summers ”as early as 2030″ soley concerns floating polar sea ice, not Greenland ice (which is grounded). Here’s the pertinent passage:

Bad news is coming from other sources as well. A recent NASA study has shown that the ice cap is not only getting smaller, it’s getting thinner and younger. Sea ice has dramatically thinned between 2004 and 2008. Old ice (over 2 years old) takes longer to melt, and is also much harder to replace. As permanent ice decreases, we are looking at ice-free summers in the Arctic as early as 2030. They say you can’t be too young or too thin, but this unfortunately doesn’t apply to Arctic sea ice.

I don’t usually defend Greenpeace and don’t plan to make a habit of it. My point is not that Greenpeace is a reliable source but that we skeptics must exercise due diligence. If something looks too good to be true (in this case, a confession of fraud by a political adversary), it probably is.

Stick to exposing true lies and do not peddle factoids. Alarmists are gunning for us everyday. The last thing we need to do is shoot ourselves in the foot!

Read more on OpposingViews.com: Greenpeace Admits to Ice Cap Melting Exaggeration