There is an old workplace joke that malingering employees who fail to get their jobs done use the same old lame excuses. Signs posted around the office or shop floor list the excuses, assign each a number, and advise layabouts to turn in their excuses by number, in the interest of efficiency.
The workplace list of excuses has been cleverly adapted by Skeptical Science, an independent Australian site that respectfully but relentlessly takes apart skeptics' arguments against a human link to climate change. The site is maintained at his own expense by John Cook, a solar physicist who carefully points out that he is not a climate scientist and relies entirely on peer-reviewed scientific literature.
Like the old workplace list of excuses, Skeptical Science assigns to skeptics' arguments a number corresponding to their frequency of use.
The old canard about the sun being the culprit ranks number 1 on the Skeptical Science list.
It was the argument seized upon by Ron Johnson, Republican candidate for the U.S. Senate from Wisconsin, who suggested in an editorial board interview with the Milwaukee Journal Sentinel that sunspots are the cause of climate change.
Johnson was not the first to seize on that discredited tale, nor is he likely to be the last. Had Johnson taken a little time to study the matter, rather than follow cue cards from the school of dunce cap science, he would have found that solar activity cannot explain the observed increase in global average temperatures. Solar activity has been largely stable for the past 40 or so years. Moreover, the pattern of warming - hotter in the troposphere, cooler in the stratosphere, more warming at the poles than at the equator - does not fit the pattern that would be evident if solar activity were the leading cause of observed warming.
Ranking number 2, which Johnson also parroted, is the argument that there have been past instances of rising global temperatures, well before "there were tons of cars on the road," as he put it. So there.
The refutation is that climate responds to forcing mechanisms. The climate doesn't care if those forcing mechanisms are natural or are the result of human activities - which in the current case is the injection of heat-trapping gases into the atmosphere through the burning of fossil fuels. When you inject heat-trapping gases into the atmosphere, they trap heat. Natural factors, like the aforementioned sun, cannot explain the recent, rapid increase in global average temperatures.
It's a logical fallacy to argue that because past climate change episodes had natural causes, then the current bout of climate change must have natural causes. It's like arguing that since lightning can cause forest fires, all forest fires are caused by lightning.
No. 3 on Skeptical Science's list of specious arguments is that "there is no scientific consensus." Johnson trotted that one out too, insisting that global warming is "not proven by any stretch of the imagination."
Johnson didn't quantify precisely what he meant. Maybe he didn't know. What he should know is that scientists arrive at conclusions through a laborious process of testing alternative explanations for a phenomenon, through a process of gathering evidence and logical reasoning as to what the evidence means. They argue with each other during that process - a lot, as a matter of fact - but a point arrives at which one explanation for a phenomenon has survived the gauntlet of testing and has stood up to scrutiny better than the others.
A 2009 study asked 3,146 earth scientists whether they thought human activity is a significant contributing factor for the rise in global temperatures. Of the scientists who are not climate experts and have not published climate research results, 77 percent said "yes." Of the scientists who do climate research and publish their results, "yes" drew 97.5 percent. The study concluded: "It seems that the debate on the authenticity of global warming and the role played by human activity is largely non-existent among those who understand the nuances and scientific basis of long-term climate processes."
That explanation - the consensus, if you like - is not enshrined on golden tablets forever. If other scientists have an idea for a better explanation, they're welcome to put it to the test, but it won't get a free pass, no matter how politically correct it might be among the Ron Johnsons of the world.
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