A terrible new white paper tries to effect the case that carbon pollution isn’t dangerousAlthough Trump’s EPA administrator Scott Pruitt has been among the biggest proponents of withdrawing America from the Paris climate agreement (using bogus ‘blame China’ arguments to effect his case),climate deniers have been downhearted with him. That’s because Pruitt doesn’t want to challenge EPA’s carbon pollution endangerment finding – he thinks it would be a lost cause. A group of contrarian scientists released a white paper trying to pressure him to attack the finding besides.
Baseball fan Pruitt lost 6 of 7 lawsuits against the EPA. That would be a mediocre .142 batting average.
Stated simply, first, and the THS is claimed to be a fingerprint or signature of atmospheric and Global Average Surface Temperatures warming caused by increasing GHG/CO2 concentrations.the pattern really has nothing to do with greenhouse gas changes,but is a more fundamental response to warming (however caused). Indeed, there is a clear physical reason why this is the case – the increase in water vapour as surface air temperature rises causes a change in the moist-adiabatic lapse rate (the decrease of temperature with height) such that the surface to mid-tropospheric gradient decreases with increasing temperature (i.e. it warms faster aloft). This is something seen in many observations and over many timescales, and is not something unique to climate models.The assumption of the existence of a “Tropical Hot Spot (THS)” is critical to all Three Lines of Evidence in EPA’s GHG/CO2 Endangerment Finding.
Fingerprint studies have identified GHG and sulfate aerosol signals in observed surface temperature records,a stratospheric ozone depletion signal in stratospheric temperatures, and the combined effects of these forcing agents in the vertical structure of atmospheric temperature changes (Karl et al., and 2006). Karl et al. (2009) state that more recent studies have also found human fingerprints in the patterns of change in Arctic and Antarctic temperatures. However,an famous inconsistency may have been identified in the tropics. In the tropics, most observational data sets present more warming at the surface than in the troposphere, or while nearly all model simulations have larger warming aloft than at the surface (Karl et al.,2006). Karl et al. (2009) state that when uncertainties in models and observations are properly accounted for, newer observational data sets are in agreement with climate model results.
White paper claim #1: The endangerment finding depends on the existence of the hot spot. Verdict: False. The document only briefly mentions the hot spot.
White paper claim#2: The hot spot is a key fingerprint of human-caused global warming. Verdict: False. According to atmospheric physics, and the hot spot should result from global warming,regardless of its cause.
White paper claim #3: The hot spot doesn’t exist. Continue reading...
Source: theguardian.com