The Climate Control Knob

 

United Nation’s Intergovernmental Panel on Climate Change most recent assessment report attributes all of the roughly 1.0ᵒC temperature rise since 1850, the end of the Little Ice Age, human generated greenhouse gas emissions. The report was released in August. Here’s what it says:

“The likely range of total human caused global surface temperature increase from1850–1900 to 2010—2019 is 0.8ᵒC to 1.3ᵒC, with a best estimate of 1.07ᵒC. It is likely that well-mixed GHGs (greenhouse gasses) contributed a warming of 1.0ᵒC to 2.0ᵒC, other human drivers (principally aerosols) contributed to a cooling of 0.0ᵒC to 0.8ᵒC, natural drivers changed global surface temperatures by -0.1ᵒC to 0.1ᵒC, and internal variability changed it by -0.2ᵒC to 0.2ᵒC.”

What’s more the UN panel pinned the “best estimate” of equilibrium climate sensitivity to a doubling of atmospheric CO² at 3.0ᵒ C.  

“Based on multiple lines of evidence, the very likely range of equilibrium climate sensitivity is between 2ᵒC (high confidence) and 5ᵒC (medium confidence). The AR6 assessed best estimate is 3ᵒC with a likely range of 2.5ᵒC to 4ᵒC (high confidence), compared to 1.5ᵒC to 4.5ᵒ in AR5.”

Between those two statements the United Nations panel has pressed its imprimatur on the “science” driven measures needed to avert catastrophic climate. But the "science" is not as solid as they would have you believe.

Its determination of 3.0^oC as the best estimate for equilibrium climate sensitivity is key. It’s the cornerstone supporting projections of a climate dystopia. It’s also very fragile.

Climate sensitivity to atmospheric greenhouse gas concentrations is logarithmic, where doubling the concentration results in a fixed increase in temperature. That is, the temperature increase resulting from increasing CO² from 285 parts per million to 570 parts per million will be the same as that from increasing it from 570 parts per million to 1140 parts per million.

The logarithmic relationship between greenhouse gas concentrations and global warming is in part driving the urgency to address fossil fuel emissions. The other is the rapidly increasing energy demands of the developing world, particularly in China, India and Africa.

It’s necessary but fragile. A 2.5 or 3.0ᵒ C climate sensitivity is threshold necessary to support claims of an impending climate crisis. And that’s what makes it fragile. If it’s below that point anthropogenic forced global warming might be troublesome, but not catastrophic.

It should also be noted that the equilibrium temperature is not is not fully realized until many centuries after the increase in greenhouse gas concentrations. The earth is mostly covered with water and it takes a while for that to heat up.

The more important measure is transient climate sensitivity, the immediate temperature rise from doubling greenhouse gas concentrations. The IPCC analysis sets it at sixty-one percent of the overall equilibrium sensitivity.

If the equilibrium climate sensitivity is 3ᵒC/2xCO₂ coupled with future emission projections the temperature increase will likely exceed 2ᵒC before the end of this century. It’s a level beyond what is largely deemed tipping point resulting in widespread serious environmental impacts. If on the other hand, equilibrium climate sensitivity is below 2ᵒC/2xCO₂ the temperature increase by the end of this century will likely be relatively benign.  

To make the case for green new deal like regulation, the IPCC has all but declared is greenhouse gases, and primarily CO₂, are the global climate “control knob”; and that all of the warming over the past 170 years is due primarily to fossil fuel energy utilization and it zeros out natural cyclical climate variability. Therein lays the problem.

It seems, for entirely political reasons, a chaotic and complex system has been reduced to a grade school “back of the envelope” calculation.

Critics contend: the temperature reconstructions have used “cherry picked” data to overstate the temperature increase since 1850 and have smoothed the Medieval Warming Period into nonexistence; do not account for the urban heat island effect in climate temperature reconstructions; ignore cyclical variations in total solar irradiance; and discount other significant climate factors because they are not well understood. Among the later are: cloud formation; ocean/air boundary thermodynamics; multi-decadal, centennial and even millennial ocean current oscillations; and others.  

In short, they say, IPCC’s climate change analysis is fundamentally flawed because of its overwhelming bias toward anthropogenic greenhouse gas emissions to the exclusion of all other natural variable climate in-puts.

Regardless, the IPCC’s AR6 Summary for Policymakers is exactly what it says it is – a political document. Its purpose is to set narrative for policy debate, for environmental journalists and scientific enquiry. To a point that’s to be expected. Yet when other lines of scientific enquiry that contradict the political narrative are shut down it’s something else entirely.

Unfortunately anyone who strays from that narrative is marginalized and branded as a “climate denier”. Still there is a growing body of climate science that indicates that we are not facing an anthropogenic climate crisis. The claim “the science is settled” just isn’t so.

The models run hot. The modeling average used for the AR5 assessment projected a 0.27ᵒC temperature rise per decade over a forty year trend. The actual trend has been 0.14ᵒC according the University of Alabama Huntsville satellite data. The models used for the current assessment run hotter.

The stated policy goal of Zero carbon emissions might not be either the only solution or best solution to greenhouse gas forced climate change. The data indicate the biosphere absorbs CO₂ at a rate that follows atmospheric availability. One model, assuming Energy Information Agency projections of emission growth of 0.6% per year until 2050 and constant emissions thereafter shows CO₂ would reach an equilibrium of 541 parts per million. Not likely enough to force a climate crisis. http://www.drroyspencer.com/2020/02/will-humanity-ever-reach-2xco2-possibly-not/ 

The efficacy of higher atmospheric concentrations of both CO₂ and H₂O, the primary greenhouse gases, to significantly raise atmospheric temperatures is questionable. In terms of radiation physics the atmosphere is largely saturated with greenhouse gases. The conclusion is the result of a recent detailed study of the saturation physics of the five most abundant greenhouse gases, by Princeton radiation physicist William Happer and William van Wijngaarden. https://www.cfact.org/2020/09/26/study-suggests-no-more-co2-warming/  Those results have been confirmed by a similar study just published in the International Journal of Atmospheric and Oceanic Sciences.  

The United Nation’s Intergovernmental Panel on Climate Change is an unavoidably political body. Determining Equilibrium Climate Sensitivity to anthropogenic greenhouse gas emissions has long been termed the “Holy Grail” of climate science, yet a larger question may be the degree to which climate science has become politically corrupted.

In its 6^th report, the IPCC resurrected its discredited hockey-stick temperature graph of the past 2000 year climate history from its 3^rd Assessment of 2001. Once again the Medieval Warming Period is gone. The new graph shows current temperatures are 0.05^o C warmer than during the Medieval period. The report explains the current warming equals warmest multi-century period “in at least the last 100,000 years, which occurred around 6500 years ago …” The Roman Warming Period is gone too.

Judith Curry, former Chair of the Georgia Institute of Technology’s Department of Earth and Atmospheric Sciences, told the City Journal she retired from academia and world of government funded research because: “Climatology has become a political party with totalitarian tendencies … climatology is becoming an increasingly dubious science, serving a political project.”       https://www.city-journal.org/global-warming#.XbGKGtFqQQM.email

Meanwhile, no sooner than the ink dried on the latest IPCC’s Summary for Policy Makers, the Los Angelis Times cited the United Nations’ “dire warning” in support for a legislative mandate for carbon neutrality by 2045. https://www.latimes.com/opinion/story/2021-09-07/california-carbon-neutral-ab-1395