When U.S. Sen. James Inhofe, chairman of the Senate Environment and Public Works Committee, brought a snowball onto the floor of the U.S. Senate last week and proclaimed it evidence that global warming is a fraud, I thought he had set a standard of silliness in the global warming "debate" that would probably last a long time.

Alas, that standard lasted a week. Because this is the latest "evidence" that has gotten climate-change deniers all a-ga-ga:

Climate-change deniers have seized on the 43-year-old video as a great confirmation of something or other, with the "breaking news" sweeping through the conservative blogosphere faster than a joke about Nancy Pelosi and facelifts. It has already been featured on Drudge and Breitbart and Newsbusters and HotAir and the Media Research Center and RightwingNews, among many others, no doubt.

So I decided to investigate and report back on what it all means:

Julia Seymour at Media Research Center tells us that the 43-year-old video is important because it's "completely different from the media's line today that global warming is settled science." Hmmmm. Marc Morano of the right-wing Climate Depot says that "Having Cronkite's image and face discussing global cooling fears reveals the fickleness of the climate change claims.”  Ed Morrisey at Hot Air points out that John Holdren, now President Obama's science adviser, was also among those who at least suggested back in the mid-'70s that an ice age was possible. And at RightWingNews we're told that this "proves" the existence of a "consensus" two generations ago about global cooling.

Let me make a few points in response:

1.) If the "consensus" in favor of a new ice age was indeed as widespread as the deniers like to pretend, they wouldn't be grabbing so desperately at this one small, isolated data point -- citing one suggestion by one British professor more than 40 years ago -- to prove their case. The fact that they're trying to make so much of this proves just how scarce such evidence really is.

2.) The British scientist cited by Cronkite, Hubert Lamb, did indeed surmise back in the early '70s that natural forces -- not mankind -- might drive the planet toward a new "little ice age", but not for another 4,000 to 7,000 years. Subsequent research caused Lamb to withdraw that assertion and acknowledge the role played by carbon in the atmosphere.

3.) Holdren, President Obama's science adviser, argued back in the '70s that global warming and cooling were BOTH possible outcomes of what he called "global thermal pollution," while today he argues strongly that human beings are driving a climatological warming.

4.) Scientists such as Holdren who change their minds over a period of 43 years are not guilty of "fickleness." They are guilty of science. In fact, changing your mind as the evidence changes is pretty much a basic test of intelligence. Refusing to change one's mind to account for changing evidence, on the other hand, can be described as ignorance, ideology or wilfull self-deception -- it can be a whole lot of things. Smart is not on the list.

Let me close with an example of the scientific method at work:

I noted above that I thought Inhofe's little snowball stunt represented the most intellectually foolish argument I've seen against climate change. Now that we have additional data, I am forced to revise that theory:  The Cronkite video is now the most intellectually foolish argument I've seen against climate change. And since tomorrow is another day, and since I'll be reading at least of few of the comments below, even that theory may have to be revised.

Because that's the way it is, Friday, March 6, 2015.