The past 150 years provide a natural experiment that shows that the global temperature anomaly has not responded to our anthropogenic carbon dioxide emissions
Justin Gillis (“Global Temperatures Highest in 4,000 Years,” March 7, The New York Times) reporting on an effort by Marcott, Shakun, Clark and Mix published in Science, noted that; “Global temperatures are warmer than at any time in at least 4,000 years, scientists reported Thursday, and over the coming decades are likely to surpass levels not seen on the planet since before the last ice age.”
Of course, this falsified Mr. Gillis’ earlier (Jan. 9) claim that “Not Even Close: 2012 Was Hottest Ever in U.S.” on the front page of “the nation’s newspaper” (The New York Times). This is not surprising since scientists agree Earth has been much warmer many times in the past. The publication of such an arrantly untrue headline seems more consistent with a propaganda campaign than unbiased reporting.
More recently Mr. Gillis reports (“Heat Trapping Gas Passes Milestone, Raising Fears,” May 10) that atmospheric carbon dioxide levels have “not been this high for at least three million years.”
The 2007 report by the Intergovernmental Panel on Climate Change (IPPC) substantiated the strong correlation between the GTA and atmospheric carbon dioxide levels up to the beginning of the Industrial Revolution.
It is striking that while temperatures are the highest they have been in 4,000 years, atmospheric carbon dioxide levels are higher than they have been in over 3 million years. The correlation has been lost; the past 150 years provide a natural experiment that shows that the GTA has not responded to our anthropogenic carbon dioxide emissions.
This is precisely what climate scientist Kevin Trenberth was reflecting when he wrote, “The fact is that we can’t account for the lack of warming at the moment and it is a travesty that we can’t.”
Disinterested scientifically literate people realize that the last 150 years is an experiment that has shown that our anthropogenic carbon dioxide has not had any effect on the GTA.
We also realize that 100 million years ago, in the mid-Cretaceous period, atmospheric carbon dioxide levels were 1,000 ppm and warm-water organisms thrived at both poles.
Earth has cycled through many warm periods and ice ages since then, making the claim that a “continuing rise could be catastrophic” patently absurd.