This commentary originally appeared in the Daily Caller on July 20, 2016.
A former NASA climate scientist has put out a new report criticizing the argument that global warming is settled science.
“It should be clear that the science of global warming is far from settled,” said Dr. Roy Spencer, a former NASA scientist who now co-runs a major satellite temperature dataset at the University of Alabama-Huntsville.
“Uncertainties in the adjustments to our global temperature datasets, the small amount of warming those datasets have measured compared to what climate models expect, and uncertainties over the possible role of Mother Nature in recent warming, all combine to make climate change beliefs as much faith-based as science-based,” Spencer wrote in a report published by the conservative Texas Public Policy Foundation.
“Until climate science is funded independent of desired energy policy outcomes, we can continue to expect climate research results to be heavily biased in the direction of catastrophic outcomes,” Spencer wrote.
“Besides, if global warming is settled science, like gravity or the Earth not being flat, why isn’t the agreement 100 percent?” Spencer asked. “And since when is science settled by a survey or a poll? The hallmark of a good scientific theory is its ability to make good predictions.”
“From what we’ve seen, global warming theory is definitely lacking in this regard,” Spencer wrote.
Spencer also explained why climate models tend to over-predict how much warming will occur as greenhouse gas emissions rise. Spencer argues a warming bias is built into the models themselves.
“Since climate models can be ‘tuned’ to produce a rather arbitrary amount of warming, they were tuned to be ‘sensitive’ enough so increasing carbon dioxide alone was sufficient to cause the observed warming,” he wrote.
“It was assumed that there was no natural component of the warming, since we really don’t know the causes of natural climate variations,” he wrote. “As a result, none of the models were prepared for the global warming “hiatus” we have experienced since about 1997, because their climate sensitivity was set too high. The models continued to warm after 2000, while the real climate system essentially stopped warming.”
Indeed, Spencer’s satellite data, which measures the average temperature of the lowest few miles of the atmosphere, showed no significant global warming trend for more than 21 years before an incredibly powerful El Nino warming event hit late last year.
El Nino is a naturally occurring warming of the tropical Pacific Ocean and tends to warm the planet. Satellite temperatures are extremely sensitive to El Ninos (and La Nina cooling events), so mid-tropospheric readings spiked in early 2016.
But temperatures have come down after El Nino faded, and now it looks like a La Nina is setting in. Some even expect the so-called “hiatus” in global warming to return after this year’s La Nina ends.