In an Oct. 4 interview with The Epoch Times, the study’s author, Nicola Scafetta, noted that models assuming that our climate system is quite sensitive to carbon dioxide are “more alarming” than those assuming it is less sensitive.
“This alarm–this ‘climate emergency,’ in my opinion, does not exist,” Scafetta said.
Scafetta is an associate professor in the Department of Earth Sciences, Environment and Georesources at the University of Naples Federico II in Italy.
It’s crucial to work out our atmosphere’s actual equilibrium climate sensitivity, or ECS. (In plain language, ECS means the temperature change that can ultimately be expected from a doubling of carbon dioxide in the atmosphere.)
Higher climate sensitivity could help justify expansive spending to mitigate our production of greenhouse gasses. But if the climate’s sensitivity is lower, the case for that sort of spending may be weaker.
Scafetta used 38 models to hindcast (that is, to forecast backward in time) the temperature since 1980. That allowed him see how well the results compared with actual temperature data, including measurements taken at the Earth’s surface and satellite-based measurements from the University of Alabama in Huntsville.
Huntsville’s satellite data show that temperatures have increased roughly 0.13 degrees Celsius per decade since 1980. That’s less than in other satellite data sets.
What’s more, those satellites track warming in the troposphere, the lowest layer of the atmosphere. That area should be warming faster than the surface–yet the Huntsville records show less warming than surface-based measurements.
Scafetta used the Huntsville data to set the lowest possible limit for warming at the surface.
He noted that a range of factors could distort surface records.
“If the [temperature] station gets dirty for any reason, then it will start to record a higher temperature,” he said.
Scientists debate whether the urban heat island effect still biases surface temperatures upward.
Scafetta determined that middling or high ECS models consistently overstated past warming. Low ECS models, by contrast, were more consistent with surface temperature data.
Yet, by comparing surface warming records on the ocean with those on land, he said he found evidence that land-based measurements may also suffer from bias in favor of warming.
While scientists generally expect greenhouse gasses to cause more warming on land than at sea, surface temperature records show the land warming much quicker and faster than some might have thought. Indeed, in Scafetta’s analysis, surface data from the land exhibited a much stronger warming trend than the models he tested and the Huntsville satellite data.
If land surface temperature records are, in fact, distorted, then even the low ECS models may overestimate the climate’s sensitivity.
The upshot? According to Scafetta, our atmosphere’s ECS could be as low as 1.5 degrees Celsius, much lower than middling or high ECS estimates, which top out at 5.7 degrees Celsius.
During his interview with The Epoch Times, he added that natural oscillations–for example, the solar cycle–also could be significantly contributing to recent warming. That would drive down the ECS even further.
NASA Critic: ‘This Is Hilarious’
Scafetta said his paper is new enough that it will take time for substantive responses to roll in.Yet, he and his article have already been harshly criticized by climate scientist Gavin Schmidt, who took to Twitter to voice his complaints.
“This is hilarious,” wrote Schmidt, who leads the NASA Goddard Institute for Space Studies.
He also questioned a graph that compared Huntsville satellite temperature data with surface temperature data.
“[H]e’s not comparing like with like,” Schmidt said.
The two have tangled before.
In an Oct. 4 email, Scafetta told The Epoch Times that Schmidt’s Twitter thread “continuously misinterprets” his research, disputing, among other things, the technical criticism of how his analysis treats uncertainty.
Addressing the inclusion of Huntsville satellite data, Scafetta said his article made it clear they marked a lowest limit for surface warming.
He also explained the exclusion of satellite temperature records from Remote Sensing Systems, the basis of another Schmidt critique.
“It would match the surface records and would be unnecessary,” he said, adding that his paper had already explained why those data were omitted. (That explanation can, in fact, be found on page 3 of Scafetta’s publication.)
Accusations of Rejection Denied by Journal
Schmidt’s harshest comments concern the relationship between the new article in Climate Dynamics and a past Scafetta paper. That work appeared earlier in this year in Geophysical Research Letters.“One might speculate,” Schmidt said, that Scafetta first submitted the new research to Geophysical Research Letters as a corrected version of that earlier paper. Schmidt guessed it may have been rejected there and then sent to Climate Dynamics, where, in his words, it could have enjoyed “more sympathetic/naive reviewers.”
Scafetta flatly rejects Schmidt’s latest accusation, calling it “false and ridiculous.”
“I never submitted it to [Geophysical Research Letters],” he said in his Oct. 4 email.
The editor-in-chief of that journal, Johns Hopkins University’s Dr. Hari Rajaram, told The Epoch Times in an Oct. 6 email that the new paper in Climate Dynamics was not initially sent to Geophysical Research Letters.
He said that the two papers are being evaluated by a team with American Geophysical Union (AGU) Publications, which publishes Geophysical Research Letters.
“I cannot share the details of these investigations at this time,” he wrote.
The Epoch Times reached out to Schmidt seeking his response to Rajaram’s comments.
“The bottom line is that Scafetta’s conclusions are unsupported by his analysis, either in the GRL paper or the new Climate Dynamics paper. A good review of either paper should have seen that,” Schmidt wrote in an Oct. 6 email.
