... "Even though Democrats controlled both houses of Congress during the first two years of the Obama presidency, bespoke cap-and-trade legislation stalled in the Senate, forcing the Obama administration to use agency rule making instead.
If politics create a forbidding hurdle to any future congressional action on climate, it is paradoxically the science—and the indeterminacy of court-deference doctrines under the Administrative Procedure Act—that could defeat agency action.
Under the Administrative Procedure Act, regulations get quashed if they are found to be “arbitrary and capricious.”
... The imprecision of climate forecasts may have something to do with why no significant federal legislation has been passed to restrict CO2 emissions.
In 2016, the Supreme Court put a stay on the Obama administration’s expansive Clean Power Plan because it lacked legislative backing.
... In 2009, the Obama administration EPA issued an “Endangerment Finding” from CO2 and other human emissions.
The evidential basis backing that finding was limited solely to General Circulation Climate Models (GCMs).
All the GCM models, save one, proved incapable of simulating the three-dimensional behavior of the lower atmosphere,
and the one that did work, from the Russian Institute for Numerical Modeling, predicts less future warming than all the others.
Best scientific practice would emphasize this model, but it also would stunt or reverse any expensive policies because the future warming is so small and distant.
The Social Cost of Carbon (SCC) was a concept used by the Obama administration to justify sweeping policies, but the administration failed to follow OMB guidelines in the use of discount rates.
Using warming suggested by both the Russian model and observationally based calculations of future warming,
along with enhanced planetary greening caused by increasing atmospheric CO2, the SCC becomes negative (i.e., a benefit) across all discount rates under consideration.
Politically, it will be very difficult for the Biden administration to pass significant global warming legislation.
With an even more constitutionalist Supreme Court than the one that stayed Obama’s Clean Power Plan, it is highly likely that any sweeping actions absent legislation will be voided by the Court.
... scientists are still struggling with the most important question of climate policy:
By how much do CO2 emissions increase temperatures?
... The degree of uncertainty in our technical understanding of the climate is a crucial factor in getting the policy right.
... The regulations fostered by the Endangerment Finding included limits on CO2 emissions from both vehicles and stationary sources, and the related Clean Power Plan, which would have phased out coal and (soon after) natural gas in America’s power sector.
... projections used by the EPA in its Endangerment Finding were manually “tuned” to yield an unrealistic fit to observed early 20th century temperatures.
... For years, climate scientists had been mum in public about their “secret sauce:
” What happened in the models stayed in the models."
The taboo reflected fears that climate contrarians would use the practice of tuning to seed doubt about models.
... In total, the 20th century temperature history can easily be summed up:
a warming of nearly 0.5C from 1910-45,
a slight cooling from then through the mid-1970s,
followed by a warming from 1976 through 1998 that occurred at a similar rate to the earlier warming.
Tuning (meaning changing the models’ internal code to get an “anticipated acceptable” answer) to mimic the 1910-45 warming as a result of human activity (i.e., CO2 emissions, among others) is an exercise in the absurd.
By 1910, when that warming began, the concentration of atmospheric CO2 had risen from an early 19th century value of around 285 parts per million (ppm) to around 298—a tiny increase, considering that today’s concentration is around 414 ppm.
If the early warming was caused by such a small increase in CO2 concentration, it would be hotter than Hades by now.
... using generally accepted equations for the warming caused by CO2 and the cooling by simultaneous emissions of sulfate aerosols (mainly from coal combustion),
show that the 1910 concentrations could have induced a global warming of only about 0.05⁰C; instead, through 1945 it was nearly 0.5⁰,
... it is the scientist, and not the science, that determines future warming.
... It is the scientist, working within the peer pressure of an institutional setting that would react negatively to a finding that fell below the “anticipated acceptable range,” who makes this decision.
... In fact, the tuning strategy was not even part of the required documentation in the CMIP5 simulations [the latest collection of climate models ...
... there has been no real narrowing of the range of prospective climate change since the 1979 National Academy of Sciences report Carbon Dioxide and Climate: A Scientific Assessment, chaired by Jule Charney of MIT.
The “Charney Sensitivity,” as it came to be called, was in the range of 1.5-4.5⁰K (=⁰C) for the equilibrium lower atmospheric warming caused by a doubling of CO2.
Subsequent assessments, such as some of the IPCC ARs, also listed the midpoint, 3⁰C, as a “most likely” value.
... The range of the (latest) CMIP6 models currently available (and almost all are now available), is 1.8-5.6⁰C, and an estimate of the mean (based upon a nearly complete model set) is 4.0⁰C.
In summary, climate science suffers from the oddity that the more funding is expended, the less precise outcomes ensue.
... there is one model that tracks reality: the Russian Institute for Numerical Modeling model INM-CM4.
... Its estimate of Equilibrium Climate Sensitivity is also the lowest of all of these models, at 2.05C, compared to the average of 3.4C given in the IPCC model group.
AR5 (IPCC) made a carefully qualified attribution statement:
“It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010
was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together.”
“Half” of the observed warming in that period is about 0.3⁰C.
... The next UN IPCC report (AR-6) has been delayed to 2022 ...
The new Russian model, INM-CM4.8, has even less sensitivity to a doubling of CO2 than its predecessor—down to 1.8⁰C. Its predecessor (INM-CM4).
... It also predicts less warming than all the other models.
On the other hand, CMIP6 predicts more warming because several of the model ensemble members are warmer than the hottest model in CMIP5.
... Clearly the best scientific practice is to use the climate models that work: the Russian INM-CM4.8 (or the newer 5.0 that is in the CMIP6 suite) ...
... The Trump administration’s decision to withdraw from the Paris Agreement on Climate Change was lamented around the world, because no global response to climate change is likely to succeed without buy-in from the United States.
Yet, over the last decade and a half, America has reduced carbon emissions more than all of Europe put together.
How it has done so, however—through a widespread switch from coal to natural gas made possible by hydraulic fracturing—is cold comfort for environmentalists, for it only seems to entrench the continued primacy of fossil fuels.
But America was already unlikely to be able to meet the Obama-set Paris targets regardless of what presidential administration was in charge.
The years ahead will test this hypothesis.
... It turns out that the general understanding of climate expressed in 2007 by the Bush EPA in response to Mass v. EPA was correct at the time:
EPA needed more science before it could reach a reasoned conclusion on whether and how to regulate carbon emissions.
It has that information now—and that information no longer supports an Endangerment Finding from CO2."