Researchers ask about the extent of carbon dioxide’s climate impact


NASA scientist calls paper ‘hilarious’ on social media, but journal contradicts his ‘speculation'[ion]’ on first rejection

A September 18th paper The journal Climate Dynamics argues that the climate’s long-range sensitivity to carbon dioxide may be very low.

In an Oct. 4 interview with The Epoch Times, the study’s author, Nicholas Caffetta, said models that assumed the climate system was highly sensitive to carbon dioxide assumed it was not so sensitive. He pointed out that it was “more alarming” than the model.

“In my opinion, this alert, this ‘climate emergency’ does not exist.”

Scafetta is Associate Professor in the Department of Earth Sciences, Environment and Earth Resources at the Federico II University of Naples, Italy.

It is important to calculate the actual equilibrium climate sensitivity (ECS) of the atmosphere. (In plain language, ECS means the final temperature change you can expect when the amount of carbon dioxide in the atmosphere doubles.)

Higher climate sensitivity can help justify huge expenditures to mitigate greenhouse gas production. There is a nature.

Scafetta used 38 models to hindcast (that is, predict back in time) temperatures since 1980. This allowed us to see how well the results compare with real-world temperature data, including measurements made on the ground and satellite-based measurements from universities. Huntsville, Alabama.

Satellite data from Huntsville show that temperatures have increased by about 0.13 degrees Celsius every decade since 1980. This is a lower number than other satellite data sets.

In addition, these satellites track warming of the troposphere, the lowest layer of the atmosphere. The area should be warming faster than the surface, but the Huntsville record shows less warming than surface-based measurements.

Scafetta used the Huntsville data to set the lowest possible limit for surface warming.

He pointed out that various factors can skew the surface record.

“if [temperature] When the station gets dirty for some reason, it starts registering higher temperatures,” he said.

Scientists debate whether the urban heat island effect still increases surface temperatures.

Scafetta found that moderate and high ECS models consistently overestimated past warming. In contrast, the low ECS model was more consistent with the surface temperature data.

However, by comparing ocean surface warming records with land-based ones, we find evidence that land-based measurements may also suffer from biases in favor of warming.

Scientists generally expect greenhouse gases to cause more warming on land than in the oceans, but the record of surface temperatures shows that the oceans are warming much, much faster than some thought. indicates warming. In fact, in Scafetta’s analysis, surface data from land showed a much stronger warming trend than the models he tested and the Huntsville satellite data.

Even low ECS models may overestimate climate sensitivity if the land surface temperature record is indeed skewed.

Result is? According to Scafetta, his ECS for our atmosphere can be as low as 1.5 degrees Celsius, well below moderate or high ECS estimates, which peak at 5.7 degrees Celsius.

In an interview with The Epoch Times, he added that natural oscillations (such as the solar cycle) may also contribute significantly to recent warming. This further degrades ECS.

his past work is explored role of the sun climate change in recent decades.

Scafetta describes his methodology and findings in more technical detail. blog post On the website of climate scientist Judith Curry.

NASA critic “This is interesting”

Scafetta said his paper is new enough that it will take some time before we get a substantive answer.

But he and his article have already been heavily criticized by climate scientist Gavin Schmidt.

“This is interesting,” wrote Schmidt, who heads NASA’s Goddard Space Institute.

and twitter threadhe accused Scafetta of making various technical errors, including in dealing with uncertainty.

He also questioned the graph comparing Huntsville satellite and surface temperature data.

“[H]e is not a comparison of the same,” says Schmidt.

The two had been intertwined for some time.

in 2009 paper, Schmidt disputed Scafetta’s attribution of significant global warming to solar activity.Scafetta fought back blog post When paper his own.

In an Oct. 4 email, Scafetta told the Epoch Times that Schmidt’s Twitter thread “constantly misinterprets” his research, and, among other things, how his analysis deals with uncertainty. It refutes the technical criticism of

Scafetta said the inclusion of satellite data from Huntsville revealed that his article showed a lower bound for surface warming.

He also explained the exclusion of satellite temperature records from remote sensing systems. This is the basis for another criticism of Schmidt.

“It will match the surface record and become unnecessary,” he said, adding that his paper already explained why those data were omitted. (See page 3 of the publication.)

According to his Twitter thread, Schmidt will be revisiting Scafetta’s article in a future blog post on the website. real climate.

Rejection Charges by Journals

Schmidt’s harshest comment concerns the relationship between the new article in Climate Dynamics and the previous Scafetta paper. The study was published in his Geophysical Research Letters earlier this year.

“Some might speculate,” said Schmidt, who first submitted the new study to the Geophysical Research Letter as a revised version of an earlier paper. Schmidt speculated that it may have been sent to Climate Dynamics after being rejected there. In his words, he could have enjoyed “a more sympathetic and naive reviewer.”

He had previously criticized a paper in Geophysical Research Letters. blog post(Scafetta disputes these criticisms.)

Scafetta flatly denied Schmidt’s latest accusation, calling it “false and absurd.”

“I never submitted it [Geophysical Research Letters]’ he said in an Oct. 4 email.

The journal’s editor-in-chief, Dr. Hari Rajaram of Johns Hopkins University, told the Epoch Times in an Oct. 6 email that the new Climate Dynamics paper was not initially sent to Geophysical Research Letters. rice field.

He said the two papers have been evaluated by a team at the American Geophysical Union (AGU) Publications, which publishes Geophysical Research Letters.

“We are unable to share the details of these investigations at this time,” he wrote.

The Epoch Times reached out to Schmidt for his reaction to Rajaram’s comments.

“The bottom line is that Scafetta’s conclusions are not supported by his analysis, neither in the GRL paper nor in the new climate change paper,” Schmidt wrote in an October 6 email.

Nathan Wooster

follow