The IPCC Claimed Earth Warmed 0.6°C From 1861-2014. Now It’s Claimed Earth Warmed 1.72°C From 1850-2015

The magnitude of claimed global warming since the mid-1800s has tripled from 0.56°C to 1.72°C in the last few years.

As recently as 1994, the IPCC claimed global surface temperatures had risen “0.3 to 0.6°C” (0.45°C) since 1861. By 2001, it was changed to 0.61°C warming from 1861 to 2000 (IPCC TAR 2001).

Image Source: IPCC TAR 2001

In 2013, the IPCC claimed there was a hiatus from warming from 1998-2012 and that “almost all CMIP5 historical simulations [111 of 114] do not reproduce the observed recent warming hiatus” (IPCC AR5 2013). In 2014 the journal Nature was still investigating “the case of the missing heat” in the 16-year hiatus (Tollefson, 2014). As recently as 2015 scientists were still pointing out “global mean surface warming has stalled since the end of the twentieth century.” (Lee et al., 2015).

HadCRUT3 – the dataset the IPCC used until AR5 – suggested a slight ~0.05°C cooling from 2001 to 2014, which would mean the warming from 1861 to 2014 amounted to about 0.56°C.

Image Source:

Now a new study (El-Borie et al., 2020) claims global surface temperatures rose 1.72°C from 1850 to 2015, which would mean more than 1.1°C warming has been added to the mid-1800s to 2010s temperature trend just in the last few years.

Image Source: El-Borie et al., 2020

Interestingly, this same paper claims Total Solar Irradiance variations alone are responsible for 0.5°C of the warming from 1950 to 2016, with the decline in cloud cover corresponding to galactic cosmic ray intensities since the early 1980s.

Image Source: El-Borie et al., 2020

So without the added/changed/adjusted temperatures during the last few years, it could be said that changes in TSI are mostly responsible for recent warming.

Perhaps this is why the added/changed/adjusted temperatures have just recently appeared.

via NoTricksZone

July 30, 2020 at 12:21PM

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