The Shindell climate sensitivity paper: another ‘GISS miss’

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Anthony Watts:

There was lots of breathless anticipation last week over the Drew Shindell paper on climate sensitivity, which was embargoed until 1800GMT on Sunday (see the embargoed PR fromNature here), but some people like Climate Nexus couldn’t help themselves and blurted it out anyway, breaking the embargo on Friday.

Long-Term Warming Likely to Be Significant Despite Recent Slowdown

A new NASA study shows Earth’s climate likely will continue to warm during this century on track with previous estimates, despite the recent slowdown in the rate of global warming.

This research hinges on a new and more detailed calculation of the sensitivity of Earth’s climate to the factors that cause it to change, such as greenhouse gas emissions. Drew Shindell, a climatologist at NASA’s Goddard Institute for Space Studies in New York, found Earth is likely to experience roughly 20 percent more warming than estimates that were largely based on surface temperature observations during the past 150 years.

…OK now have a look at what Nic Lewis has to say about it on Climate Audit. It seems the results are all about adjustments and not the actual sensitivity.

Basically Shindell used CMIP5 models does an analysis to show that there are gaps between the climate sensitivity response to different types of forcings.

So, once these are “adjusted for”, Shindell claims that the lower climate sensitivity to carbon dioxide is not possible. He’s claiming that anything lower than 1.3 is bogus.

Some adjustments applied seem almost as large as the effect. Nic Lewis writes at Climate Audit:

One of those adjustments is to add +0.3 W/m² to the figures used for model aerosol forcing to bring the estimated model aerosol forcing into line with the AR5 best estimate of -0.9 W/m². He notes that the study’s main results are very sensitive to the magnitude of this adjustment.

If it were removed, the estimated mean TCR would increase by 0.7°C. If it were increased by 0.15 W/m², presumably the mean TCR estimate of 1.7°C would fall to 1.35°C – in line with the Otto et al (2013) estimate. Now, so far as I know, model aerosol forcing values are generally for the change from the 1850s, or thereabouts, to ~2000, not – as is the AR5 estimate – for the change from 1750. Since the AR5 aerosol forcing best estimate for the 1850s was -0.19 W/m², the adjustment required to bring the aerosol forcing estimates for the models into line with the AR5 best estimate is ~0.49 W/m², not ~0.3 W/m². On the face of it, using that adjustment would bring Shindell’s TCR estimate down to around 1.26°C.

It’s just like what GISS does to the temperature record, they can’t get there without adjusting the data. They don’t represent base reality, but rather an adjusted reality:

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Ditto

11 years ago

Earth is Safe From ‘Global Warming’ Say the Men Who Put Man on the Moon

So say The Right Climate Stuff Research Team, a group of retired NASA Apollo scientists and engineers – the men who put Neil Armstrong on the moon – in a new report.

“It’s an embarrassment to those of us who put NASA’s name on the map to have people like James Hansen popping off about global warming,” says the project’s leader Hal Doiron.

Doiron was one of 40 ex NASA employees – including seven astronauts – who wrote in April 2012 to NASA administrator Charles Bolden protesting about the organization’s promotion of climate change alarmism, notably via its resident environmental activist James Hansen.

During his stint as head of the NASA Goddard Institute for Space Studies, Hansen tirelessly promoted Anthropogenic Global Warming theory. He retired last year to spend more time on environmental campaigning and has twice been arrested with former mermaid impersonator Darryl Hannah for his part in protests against surface coal mining and the Keystone XL pipe line. While still head of NASA GISS he once described trains carrying coal as “death trains” “no less gruesome than if they were carrying boxcars headed to crematoria and loaded with uncountable irreplaceable species.” Many NASA employees and former employees found his views an embarrassment.

Doiron and his team now hope to set the record straight in a report called Bounding GHG Climate Sensitivity For Use In Regulatory Decisions.