NAS Debunks IPCC Climate Change Concerns

Previous posts have detailed a retired Boeing engineer’s response to the Intergovernmental Panel on Climate Change (IPCC) claim “Human influence on the climate system is clear”.  The posts originally reflected IPCC apparent refusal to recognize global warming between 1910 and 1950, before any significant fossil emissions, was essentially the same as from 1970 to 2000 during which fossil emissions quadrupled earlier emissions.

Posts were also dubious of IPCC using computer models to claim fossil emissions must have initially 10, but later 30 times the impact of the Sun on global temperatures in order for the results to match measured temperatures.  

The posts opined IPCC ignored Ice core data from 800,000 years of temperatures and atmospheric CO2 levels for four prior Interglacial periods. Global temperatures during the Eemian Interglacial Period some 126,000 years ago were 4 deg C higher with CO2 levels 290 parts per million (ppm).  It’s “possible” the increasing temperature during the period warming was the result of some “feed back” from increasing CO2.  However the only rational reason for the subsequent drop in temperatures was a drop in energy from the Sun.  Thus it’s “likely” both warming and cooling and CO2 increasing and decreasing were driven by the Sun. 

The warming from 290 ppm CO2 reflected its ability to block radiation back to space.   A global energy flow chart for 2000 to 2004 showed  ~370 ppm atmospheric CO2  “back radiation” was ~94% of surface radiation.  (Back radiation increased to 96% for 410 ppm)    It’s “unlikely” the IPCC claim an increase in back radiation from additional fossil emissions to the current 96% level is “an existential threat”.

Again those posts attempting to debunk IPCC claims were the result of a retired skeptical Boeing engineer’s observations of readily available data.  Thus I was pleased to find “scientific support” from a National Academy of Science report published on line Nov 10, 2014.

Shortwave and Longwave Radiative Contributions to Global Warming Under Increasing CO₂

It included the following “Significance” and “Abstract”.   (The italics on the conclusions are mine.)

Significance

The greenhouse effect is well-established. Increased concentrations of greenhouse gases, such as CO₂, reduce the amount of outgoing longwave radiation (OLR) to space; thus, energy accumulates in the climate system, and the planet warms. However, climate models forced with CO₂ reveal that global energy accumulation is, instead, primarily caused by an increase in absorbed solar radiation (ASR). This study resolves this apparent paradox. The solution is in the climate feedbacks that increase ASR with warming—the moistening of the atmosphere and the reduction of snow and sea ice cover. Observations and model simulations suggest that even though global warming is set into motion by greenhouse gases that reduce OLR, it is ultimately sustained by the climate feedbacks that enhance ASR.

Abstract

In response to increasing concentrations of atmospheric CO₂, high-end general circulation models (GCMs) simulate an accumulation of energy at the top of the atmosphere not through a reduction in outgoing longwave radiation (OLR)—as one might expect from greenhouse gas forcing—but through an enhancement of net absorbed solar radiation (ASR). A simple linear radiative feedback framework is used to explain this counterintuitive behavior. It is found that the timescale over which OLR returns to its initial value after a CO₂ perturbation depends sensitively on the magnitude of shortwave (SW) feedbacks. If SW feedbacks are sufficiently positive, OLR recovers within merely several decades, and any subsequent global energy accumulation is because of enhanced ASR only. In the GCM mean, this OLR recovery timescale is only 20 y because of robust SW water vapor and surface albedo feedbacks. However, a large spread in the net SW feedback across models (because of clouds) produces a range of OLR responses; in those few models with a weak SW feedback, OLR takes centuries to recover, and energy accumulation is dominated by reduced OLR. Observational constraints of radiative feedbacks—from satellite radiation and surface temperature data—suggest an OLR recovery timescale of decades or less, consistent with the majority of GCMs. Altogether, these results suggest that, although greenhouse gas forcing predominantly acts to reduce OLR, the resulting global warming is likely caused by enhanced ASR.

The National Academy of Science would surely also conclude “absorbed solar radiation” would be “enhanced” by more solar energy from the Sun.   The only concern about current global temperatures increasing is increasing solar energy from the Sun.  The IPCC claim fossil emissions have 30 times the impact of the Sun is absurd.  

There was never any need to spend hundreds of billions each year on windmills, solar panels, or battery powered cars.  The devastation from past attempts to limit fossil emissions will be dwarfed by that from the  Green New Deal.

All because the IPCC continues to ignore real science.

Abstract

In response to increasing concentrations of atmospheric CO₂, high-end general circulation models (GCMs) simulate an accumulation of energy at the top of the atmosphere not through a reduction in outgoing longwave radiation (OLR)—as one might expect from greenhouse gas forcing—but through an enhancement of net absorbed solar radiation (ASR). A simple linear radiative feedback framework is used to explain this counterintuitive behavior. It is found that the timescale over which OLR returns to its initial value after a CO₂ perturbation depends sensitively on the magnitude of shortwave (SW) feedbacks. If SW feedbacks are sufficiently positive, OLR recovers within merely several decades, and any subsequent global energy accumulation is because of enhanced ASR only. In the GCM mean, this OLR recovery timescale is only 20 y because of robust SW water vapor and surface albedo feedbacks. However, a large spread in the net SW feedback across models (because of clouds) produces a range of OLR responses; in those few models with a weak SW feedback, OLR takes centuries to recover, and energy accumulation is dominated by reduced OLR. Observational constraints of radiative feedbacks—from satellite radiation and surface temperature data—suggest an OLR recovery timescale of decades or less, consistent with the majority of GCMs. Altogether, these results suggest that, although greenhouse gas forcing predominantly acts to reduce OLR, the resulting global warming is likely caused by enhanced ASR.

The National Academy of Science would surely also conclude “absorbed solar radiation” would be “enhanced” by more solar energy from the