Bad Week for Roy “Wrong-Way” Spencer
September 7, 2011
Last week, chronically wrong Roy Spencer, darling of denialists, had his butt handed to him (again) when the editor of the journal where his latest brick of a paper was published resigned.
It’s important to note, Roy Spencer is MOST famous for being wrong – wrong in the the very areas that should be his area of greatest strength and expertise. Some readers may remember that the blaring headlines about “Science Proves Global warming wrong” have been fixtures of the denialist media for decades – and Roy Spencer has been one of the scientists perennially cited as finally “disproving alarmist global warming science”.
During the nineties, Spencer and his partner John Christy were the toast of denial-ville for their serial mis-reading and mis-calculating of satellite temperature readings – which they incorrectly claimed showed tropospheric cooling. After 10 years of stubbornly repeating and doubling down on a series of errors, they both finally admitted they had been in error. (and see also here)
Amazingly (or not), the “serial errors in the data analysis” all pushed the (mis)analysis in the same, wrong direction. Coincidence? You decide. But I find it hilarious that the deniers and delayers still quote Christy/Spencer/UAH analysis lovingly, but to this day dismiss the “hockey stick” and anything Michael Mann writes, when his analysis was in fact vindicated by the august National Academy of Sciences in 2006.
As RealClimate commented about an earlier Spencer effort:
We now know, of course, that the satellite data set confirms that the climate is warming , and indeed at very nearly the same rate as indicated by the surface temperature records. Now, there’s nothing wrong with making mistakes when pursuing an innovative observational method, but Spencer and Christy sat by for most of a decade allowing — indeed encouraging — the use of their data set as an icon for global warming skeptics. They committed serial errors in the data analysis, but insisted they were right and models and thermometers were wrong. They did little or nothing to root out possible sources of errors, and left it to others to clean up the mess, as has now been done.
This week, Andrew Dessler, top flight atmospheric scientist of Texas A & M, (and advisor to this blog and video series) published a paper showing why Spencer is so off base.
The basic issue in the current kerfuffle is, Spencer wants us to believe that clouds are the driver, rather than a feedback, or result of, global climate change. As is often the case, there’s a fair amount of explanation needed here – luckily we have John Cook’s Skeptical Science team to help.
Andrew Dessler, a climate scientist at Texas A&M University, has released a scientific paper (Dessler 2011) that looks at the the claims made by two of a small group of “skeptic” climate scientists who regular SkS readers will be familiar with: Roy Spencer and Richard Lindzen. Both were co-authors on peer-reviewed papers released this year (Spencer & Braswell  & Lindzen & Choi ) which, once again, sought to overturn the orthodox view of climate. Dessler (2011)finds that the conclusions of these two papers are unsupported by observational data.
Spencer & Lindzen: Tipping reality on its head
The Spencer/Braswell and Lindzen/Choi papers have an unusual take on global warming: rather than warming causing a change in cloud cover (i.e. acting as a feedback to either increase or reduce warming), both papers claim that it’s the other way around – changes in cloud cover cause changes in the surface temperature (in the present case, warming).
Spencer/Braswell and Lindzen/Choi look at the relationship between changes in ocean heat, cloud cover (directly affecting the amount of heat lost to space), and global surface temperature over recent decades. The idea is, if the change in surface temperature over that period is affected by changes in cloud cover, but changes of the surface temperature associated with the ocean warming are small, then changes in cloud cover must be driving the present global warming.
Dessler: Putting reality back on its feet
Putting aside the problems with their energy budget equation, Dessler looks at the values Spencer/Braswell and Lindzen/Choi use for their calculations. Rather than examine the data for two of the terms in their equation (heating of the climate by the ocean & change in cloud cover allowing heat to escape to space), Lindzen and Spencer approximate them from other observations, and their results rely heavily on assumptions about the size of these values.
Rather than rely on assumptions, Dessler uses other observational data (such as surface temperature measurements and ARGO ocean temperature) to estimate and corroborate these values. Dessler finds that, in contrast to Spencer/Braswell and Lindzen/Choi, the change in cloud cover is far too small to explain the short-term changes in surface temperature, explaining only a few percent of surface temperature change. In fact, the heating of the climate system through ocean heat transport is approximately 20 times larger than the change in top of the atmosphere (TOA) energy flux due to cloud cover changes. Lindzen and Choi assumed the ratio was close to 2, while Spencer and Braswell assumed it was close to 0.5.
Dessler finds that the short-term changes in surface temperature are related to exchanges of heat to and from the ocean – which tallies well with what we know about El Niño and La Niña, and their atmospheric warming/cooling cycles.
Spencer & Braswell: A classic example of cherrypicking
In order to claim that the climate models differ from observations when comparing the surface temperature and energy leaving the Earth at TOA with the lead-lag between them, Spencer/Braswell cherrypick observational data and model results that show the greatest mismatch (Figure 1).
The blue line in Figure 1 is the TOA and Hadley Centre surface temperature data chosen by Spencer/Braswell, and the red includes other datasets of the surface temperature. The black lines are the 13 climate model runs, with the ‘crosses’ indicating 5 of the 6 models analysed by Spencer/Braswell. Although Spencer/Braswell analyzed 14 models, they only plotted the 3 with highest and 3 with lowest equilibrium climate sensitivities.
In the process, Spencer and Braswell excluded the three climate model runs which best matched the observational data. Dessler found that these three model runs were also the ones which are among the best at simulating El Niño and La Niña, which is not surprising, given that much of the temperature change over 2000-2010 was due to the El Niño Southern Oscillation (ENSO). Thus Dessler concludes that
“since most of the climate variations over this period were due to ENSO, this suggests that the ability to reproduce ENSO is what’s being tested here, not anything directly related to equilibrium climate sensitivity.”
Violating the Laws of Thermodynamics
Dessler also examines the mathematical formula that both studies use to calculate the Earth’s energy budget, and finds that it may violate the laws of thermodynamics – allowing for the impossible situation where ocean warming is able to cause ocean warming.
Much ado about nothing
The short-term change in surface temperature over the 2000-2010 period is a result of ocean heat being exchanged with the atmosphere (via ENSO). This in turn alters atmospheric circulation, which alters cloud cover, but the impact of cloud cover on surface temperature only explains a small percentage of the surface temperature change. Thus the lead-lag relationship between heat leaving the Earth at TOA and surface temperature reveals nothing about what is driving the short-term surface temperature change.
In short, the “skeptic” hypothesis that changes in cloud cover due to internal variability are driving global warming does not hold up when compared to the observational data. Once again we have two heavily-hyped “skeptic” papers that have failed to live up to their billing.
While Wagner’s resignation as editor-in-chief casts a shadow of impropriety over SB2011, Dessler’s new paper titled “Cloud variations and the Earth’s energy budget” goes to the core of the paper’s scientific arguments and finds them deficient. First, Dessler finds that SB2011′s first equation appears to violate conservation of energy (“energy can never be created or destroyed”), one of the most fundamental laws of physics. The problem is that the way Spencer and Braswell wrote their equation permits the ocean to change temperature without additional energy, a situation that is analogous to a cup of coffee sitting on a desk top suddenly warming up for no reason.
The bulk of Dessler’s paper is devoted to the second error in SB2011, namely that the authors dramatically underestimated a critical ratio in their equation because they didn’t constrain their equation using measured data from the real world. SB2011 assumes that the ratio in question was about 0.5, but real data requires that the ratio be closer to 26, an error of about 50x. When the constrained ratio is used in the equations in SB2011, the paper’s results are suddenly right in line with the very models and papers that SB2011 was supposedly disproving.