If you saw the following statements, what would you think?
1. “[S]ince the last [IPCC] report it is also often stated that the science is settled or done and now is the time for action.”
2. “In fact there are no predictions by IPCC at all. And there never have been.”
3. “None of the models used by IPCC are initialized to the observed state and none of the climate states in the models correspond even remotely to the current observed climate.”
4. “Moreover, the starting climate state in several of the models may depart significantly from the real climate owing to model errors. I postulate that regional climate change is impossible to deal with properly unless the models are initialized.”
5. “The current projection method works to the extent it does because it utilizes differences from one time to another and the main model bias and systematic errors are thereby subtracted out. This assumes linearity. It works for global forced variations, but it can not work for many aspects of climate, especially those related to the water cycle.”
6. “However, the science is not done because we do not have reliable or regional predictions of climate.”
Would you think…
a) The writer is obviously a shill for oil and coal corporations?
b) The writer is some doddery old skeptic the world has passed by?
c) The writer is actually one of the lead authors of the IPCC and frequently placed in the alarmist camp?
If you thought (c), well done! They’re actually the words of Kevin Trenberth of NCAR. Roger Pielke Sr has the full story. His conclusion (in part):
In terms of climate change and variability on the regional and local scale, the IPCC Reports, the CCSP Report on surface and tropospheric temperature trends, and the U.S. National Assessment have overstated the role of the radiative effect of the anthropogenic increase of CO2 relative to the role of the diversity of other human climate climate forcing on global warming, and more generally, on climate variability and change…
Policymakers should be made aware of this very significant admission by one of the Lead IPCC authors on the limitations of the IPCC report.
This is why people like me continue to follow the science and talk about it. All other things being equal, CO2 will increase the temperature, but the fact is that we still don’t know how exactly how much CO2 is contributing to climate change. Prof. Pielke Sr thinks about a quarter of the observed warming (see the linked presentation). That’s not much, especially considering what we’re being asked to do about it.