Extreme Temperature Diary- Friday November 3rd, 2023/Main Topic: Rate of Global Warming Debate Deepens Among Climate Scientists

The main purpose of this ongoing blog will be to track planetary extreme, or record temperatures related to climate change. Any reports I see of ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉

Main Topic: Rate of Global Warming Debate Deepens Among Climate Scientists

Dear Diary. I have the deepest respect for both Dr. James Hansen and Dr. Michael Mann. I became convinced that we were changing our climate due to Dr. Hansen’s testimony back during the late 1980s. I admired Dr. Mann’s research in which he and other colleagues came up with the hockey stick graph during the 1990s, which showed increased, dangerous warming during the 21st century if we as a species did not get our carbon polluting house in order. Dr. Mann likes my record count research and has been gracious enough to review my World of Thermo kids’ climate books.

This week Dr. Mann and Dr. Hansen are having a good old fashion scientific debate on how fast our planet will warm given current carbon emission rates, renewable energy progress, and polices moving the world toward green energy. Scientific debate is healthy. Back during 2017 when I first started this site, I predicted that any debate on climate change would shift from whether or not it was manmade to how fast and how bad the problem would become. I didn’t waste my time with posts that highlighted climate contrarians and won’t in the future. That ship has sailed with any climate change denialists being relegated to the ash heap of history given how hot the planet has become with no scientific explanation for that except carbon pollution.

As I keep stating, when a scientific paper comes out that gives a figure for the rate of global warming and forecasts for how hot the planet will get, I take notice and present that on a post. That is the second biggest reason for starting this site with the first being to present record temperature reports and trends. The third reason would be to present the latest climate and weather news.

In my view it appears that global warming rates are very unfortunately for the world trending towards Dr. Hansen’s argument, but there is not enough clarity here to declare him the winner. We should see definitive clarity by the end of this decade, particularly after coming off this record El Niño cycle, so stay tuned.

Here is more on Dr. Hansen’s new paper with his dire predictions with a rebuttal from Dr. Mann and a few other climates scientists via AP News:

Pioneering scientist says global warming is accelerating. Some experts call his claims overheated | AP News

Pioneering scientist says global warming is accelerating. Some experts call his claims overheated

FILE – The sun rises above a highway in Frankfurt, Germany, Aug. 2, 2022. Former NASA top scientist James Hansen is warning that global warming is accelerating faster than most models are showing, a contention that other scientists think is overblown. He argues that since 2010 there is more sun energy in the atmosphere, and less of the particles that can reflect it back into space thanks to efforts to cut pollution. (AP Photo/Michael Probst, File)

BY SETH BORENSTEIN Updated 9:04 PM EDT, November 2, 2023

One of modern climate science’s pioneers is warning that the world isn’t just steadily warming but is dangerously accelerating, according to a study that some other scientists call a bit overheated.

The work from former NASA top scientist James Hansen, who since leaving the space agency has become a prominent protester against the use of fossil fuels, which cause climate change, illustrates a recently surfaced division among scientists about whether global warming has kicked into a new and even more dangerous gear.

Hansen, who alerted much of the United States to the harms of climate change in dramatic congressional testimony in 1988, said Thursday that since 2010, the rate of warming has jumped by 50%. Hansen argues that since 2010 there is more sun energy in the atmosphere, and less of the particles that can reflect it back into space thanks to efforts to cut pollution. The loss of those particles means there’s less of the cooling effect that they can have.

Hansen said a key calculation used in figuring out how much the world will warm in response to carbon pollution shows much faster warming than the United Nations’ Intergovernmental Panel on Climate Change estimates. He called the international goal of limiting warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) since pre-industrial times “deader than a doornail” and said a less stringent goal of 2 degrees Celsius (3.6 degrees Fahrenheit) is on its deathbed. That matters because increases in average global temperatures lead to more frequent and intense extreme weather events.

“The next few years will show that we indeed do have an acceleration in the global warming rate,” Hansen said in a press briefing. “And it’s based on simple good physics.”

“The planet is now out of (energy) balance by an incredible amount, more than it ever has been,” said Hansen, who has been nicknamed the Godfather of Global Warming.

Several climate scientists contacted by The Associated Press expressed skepticism about Hansen’s study, tinged with respect for his long-term work.

Hansen’s study in Thursday’s journal Oxford Open Climate Change is broad-ranging “but has little by way of analytical depth or consistency checks when making claims quite far outside the norm,” said Robin Lamboll, a climate scientist at the Imperial College of London. “It seems primarily aimed at convincing policymakers rather than scientists.”

University of Pennsylvania climate scientist Michael Mann, who insisted that since 1990 warming is steadily increasing but not accelerated, posted a rebuttal to Hansen’s claims and said climate change right now is bad enough and there’s no need to overstate the case. Mann said “it has always been risky to ignore (Hansen’s) warnings and admonitions” but when claims are made so out of the mainstream the standard for evidence is high, and he said Hansen hasn’t met them.

Yet a check of National Oceanic and Atmospheric Administration data lends support to Hansen’s modeling.

Hansen’s study said from 1970 to 2010, the world warmed at a rate of 0.18 degrees Celsius per decade, but projected that would increase to a rate of at least 0.27 degrees Celsius per decade after 2010. NOAA data shows that 0.27 degrees is the rate since September 2010.

That starting date is key because that’s when scientists could start to see the effect of clean air regulations that reduced aerosol pollution and the amount of sulfur in fuel used by ocean shipping, Hansen said. That type of more traditional sooty air pollution has a cooling effect that masks a fraction of the warming from the burning of coal, oil and natural gas, Hansen and many other scientists said.

When scientists try to figure out future and past warming one of the crucial variables is climate sensitivity, which is how much the world warms when carbon dioxide levels in the air double. These calculations have had a wide range and scientists have yet to settle on it, but the latest U.N. climate panel said it is within a range of 2 degrees Celsius to 5 degrees Celsius, with the likely range between 2.5 and 4 degrees and 3 degrees being a good midpoint.

Hansen’s study has it at 4.8 degrees Celsius. That’s within the widest range, but barely.

It’s that high because past research was based on wrong calculations of how fast the world warmed between glacial periods, Hansen said.

Past calculations were based on plant and animal fossil data, figuring microbiotic organisms wouldn’t adapt to warming, but would move to their preferred temperature range. Hansen said recent research shows that the organisms adapt and stay put, and when his team calculated past temperature changes based on chemical, not biological markers, it showed much faster warming for when carbon dioxide doubled in Earth’s ancient history.

Studies on climate sensitivity vary widely and are inconsistent, with another recent study showing 2.8 degrees not 4.8, said climate scientist Zeke Hausfather of Berkeley Earth and the tech company Stripe. He said Hansen’s calculations are “not implausible but not particularly well supported by the literature.”

Stanford University climate scientist Rob Jackson, however, said “I tend to trust Hansen, despite his advocacy. I think his contention that the IPCC has underestimated climate sensitivity will prove out.”

Hansen said a more recent climate model — downplayed by the U.N. climate panel for running too hot – is actually more accurate than the ones mainstream climate scientists prefer based on cloud conditions in the southern ocean.

With a strong natural El Nino, which tends to temporarily warm the globe, and record heat in the air and in the deep oceans, scientists in the past month have split about what’s happening to the globe.

Mann said the warming the world is seeing is what has long been predicted and is not the indication of something unusual or acceleration. The increases reported, he said, are statistically insignificant.

Hausfather said the world is warming faster, but he calculated the rate at 0.24 degrees Celsius per decade instead of Hansen’s 0.27 degrees.

Read more of AP’s climate coverage at http://www.apnews.com/climate-and-environment.


Follow Seth Borenstein on X, formerly known as Twitter at @borenbears


Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.



Seth is a science writer, covering climate & other topics.

Much More:

Here are some “ET’s” recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks, as well as any extreme precipitation reports:

Here is some more new October 2023 climatology:

Here is More Climate and Weather News from Friday:

(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)

Today’s News on Sustainable, Traditional Polluting Energy from Fossil Fuel, and the Green Revolution:

More from the Weather Department:

More on the Environment and Nature:

More on Other Science and the Beauty of Earth and this Universe:

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