I know other have rebutted his work

http://rogerpielkejr.blogspot.com/2013/03/fixing-marcott-mess-in-climate-science...

But LOL looks like Marcott also debunked himself...ROFL



https://notrickszone.com/marcott-et-al-rebuttal-2013/

For consideration -

"Reconstruction of last millennia Sea Surface Temperature (SST) evolution is challenging due to the difficulty retrieving good resolution marine records and to the several uncertainties in the available proxy tools. In this regard, the Roman Period (1 CE to 500 CE) was particularly relevant in the socio-cultural development of the Mediterranean region while its climatic characteristics remain uncertain. Here we present a new SST reconstruction from the Sicily Channel based in Mg/Ca ratios measured on the planktonic foraminifer Globigerinoides ruber. This new record is framed in the context of other previously published Mediterranean SST records from the Alboran Sea, Minorca Basin and Aegean Sea and also compared to a north Hemisphere temperature reconstruction. The most solid image that emerges of this trans-Mediterranean comparison is the persistent regional occurrence of a distinct warm phase during the Roman Period. This record comparison consistently shows the Roman as the warmest period of the last 2 kyr, about 2 °C warmer than average values for the late centuries for the Sicily and Western Mediterranean regions. After the Roman Period a general cooling trend developed in the region with several minor oscillations."

https://www.nature.com/articles/s41598-020-67281-2?utm_medium=affiliate&utm_sour...

Northern Hemisphere but as they explain there is a wealth of data.

From his now closed Introduction to AGW

" Re: Introduction to AGW
Reply #79 - Yesterday at 4:42pm 
This was supposed to be, believe it or not, An Introduction to AGW!"

So having established that let's look at some facts -

"The basic physics underlying this global warming, the greenhouse gas effect, is simple. An increase in gases such as CO2 makes the atmosphere more opaque at infrared wavelengths. This added opacity causes the planet’s heat radiation to space to arise from higher, colder levels in the atmosphere, thus reducing emission of heat energy to space. "

https://arxiv.org/abs/1105.1140

From Hansen et al whom some consider the modern "father" of AGW.



Nope. The Optical thickness hasn't changed overall.



Nope. Outgoing Longwave Radiation (OLR) (heat energy) hasn't gone down.

So Hansen's climate view has been shown to be wrong.

"The partition of the outgoing long wave radiation into upward atmospheric emittance and surface transmitted radiation components is based on the accurate computation of the true greenhouse-gas optical thickness for the radiosonde data. New relationships among the flux components have been found and are used to construct a quasi-allsky model of the earth's atmospheric energy transfer process. In the 1948-2008 time period the global average annual mean true greenhouse-gas optical thickness is found to be time-stationary."

https://www.jstor.org/stable/43734929?seq=1

More heating should give higher Relative Humidity

"The resultant, more humid atmosphere, causes a hotspot over the tropics at altitudes of 10km to 12km). "

"Temperature trends from raw radiosonde data are also inconsistent with climate models, which project an upper tropospheric warming maximum, especially in the tropics"

(Santer et al. 2005; Trenberth et al. 2007; Santer et al. 2008)

"the vertical trend profiles in the tropics did not show the enhanced upper tropospheric amplification as predicted by climate models"

http://doi.org/10.1175/JCLI-D-11-00668.1

So the AGW hypothesis, according to Hansen and other luminaries, is debunked.