In the past few days, several friends have sent me links to columns in the press that seek to debunk global warming. I’ve been struck by how different columnists pretty much made the same arguments — they seem to be taken right from the same playbook — and how counter they are to the scientific evidence I’ve seen.
John Tomlinson of the Flint Journal writes that at the climate talks in Poznan, “650 of the world’s top climatologists stood up and said man-made global warming is a media generated myth without basis.” He goes on to say that global temperatures “are experiencing the biggest sustained drop in decades.” Up in the Arctic, this supposed deep chill is allegedly causing Arctic sea ice to expand to levels not seen for decades. And down in Antarctica, the ice sheets are supposedly growing.
Meanwhile, Mike Thomas over at the Orlando Sentinel doesn’t say explicitly that the Earth is plunging into a profound cooling trend, but he picks up the cooling mantra by saying that NASA had to revise its calculations and admit that “six of the 10 hottest years came before 1954, with the 1930s being particularly toasty.” Thomas goes on to note that the rate of glacial retreat in Greenland has slowed down, after having sped up dramatically prior to 2005. His conclusion: “I have gone from being a believer to being a global-warming agnostic.”
So let’s take a look at these points:
- Those 650 “scientists”? The list is an extension of an earlier one from Senator James Inhofe, which includes economists, television meteorologists, and many others with no expertise in climate science. And not everyone on the list actually wanted to be there. Meteorologist George Waldenberger, for example, wrote an irritated email asking to be removed. For more on this, go here and here.
- Temperatures are dropping? According to NASA, calendar year 2008 was indeed the coolest year since 2000. Yet it was still the ninth warmest year since 1880, when instrumental records began. And most important, the 10 warmest years all occurred between 1997 and 2008. No climate scientist I have talked to, and no climate report I have ever read, has said that warming would occur in a straight, unbroken line. Given the complexity of the climate system, of course we should expect some ups and downs. I wish I could report that the downs are now predominant, but it sure doesn’t look that way. Here are two temperature records to consider:
- What about the rate of ice loss in Greenland? Well, yes, it has dropped since 2005, as Thomas says. Quoted in a story by Richard Kerr in Science, glacial modeler Faezeh Nick of Durham University and his colleagues warn that “the recent rates of mass loss in Greenland’s outlet glaciers are transient and should not be extrapolated into the future. Chalk one up for the climate skeptics? Well, not quite. Kerr also quotes renown Pennsylvania State glaciologist Richard Alley as saying, “If you turn the thermostat too high, it will melt.”
- So how about Arctic Sea Ice? John Tomlinson of the Flint Journal alleges that “the University of Illinois’ Arctic Climate Research Center released conclusive satellite photos showing that Arctic ice is back to 1979 levels. What’s more, measurements of Antarctic ice now show that its accumulation is up 5 percent since 1980.”
Well, not really. I went to the Arctic Climate Research Center’s web site, and here is what I found:
You don’t have to look too carefully to see that sea ice is considerably less extensive today than it was in 1979.
That’s what the National Snow and Ice Data Center is reporting too. According to NSIDC, the extent of sea ice in January was the sixth lowest in the satellite record. And the long-term trend couldn’t be any clearer:
But if all that still doesn’t convince you, consider this:
Perhaps I’m imagining it, but it sure does look like all those lines show pretty clearly that sea ice extent is dropping. But if you need more evidence, check this out:
The graph clearly indicates that while sea ice has recovered somewhat after taking a dramatic hit in the summer of 2008, it is still running about 1 million square kilometers below the 1979 to 2000 mean. Any way you cut it, sea ice does not seem to be “returning to 1979 levels.
- Okay, how about Antarctica? Recent research shows that ice loss there has actually increased 75 percent over the past decade thanks to acceleration of glaciers emptying out into the ocean along the continent’s coastline. For more information, see the NASA press release here: http://earthobservatory.nasa.gov/Newsroom/view.php?old=2008012326052 And also see the abstract for the actual paper: http://www.nature.com/ngeo/journal/v1/n2/abs/ngeo102.html
That being said, I know as a journalist that with science this complicated I could easily overlook something, either because of a personal bias (hey, I’m human!) or information overload. And I also have to be open to the idea that new science could come along at any time to cast doubt on what I’ve presented here.
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