Roy Spencer

Climate Models: “Epic Failure” or “Spot on Consistent” with Observed Warming?

by Marlo Lewis on June 10, 2013

in Blog, Features

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NASA scientist Roy Spencer recently posted on his Web site some startling graphs produced by John Christy, his colleague at the University of Alabama in Huntsville. The graph immediately below compares the linear-trend temperature projections of 73 climate models with the linear trend of observed temperatures for the bulk tropical atmosphere during 1979-2012.

CMIP5-73-models-vs-obs-20N-20S-MT

The 73 models are part of the fifth phase of the Coupled Model Intercomparison Project (CMIP-5), a collaborative effort of 20+ modeling groups to inform the IPCC’s forthcoming Fifth Assessment Report (AR5). The Project’s three main objectives are to “evaluate how realistic the models are in simulating the recent past,” “provide projections of future climate change” out to 2035 and 2100, and “understand some of the factors responsible for differences in model outputs” such as different estimates of feedback effects.

Christy’s graph reveals what Spencer calls an “epic failure” of the models to match the actual behavior of the tropical atmosphere. Models that overestimate recent warming are likely to overestimate future warming as well.

Of course, observational systems may have biases and errors, but that is an implausible explanation for the mismatch. The observations come from two satellite and four radiosonde (weather balloon) datasets, which all independently give “virtually identical trends.”

What about the subset of U.S.-designed models — do they get the trend right? Nope. Take a gander at the next graph.

CMIP5-19-USA-models-vs-obs-20N-20S-MT

[click to continue…]

Social Cost of Carbon: Interagency Group Predictably Predicts Climate Change Worse Than Predicted

by Marlo Lewis on June 5, 2013

in Blog, Features

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Hold the presses! A U.S. Government interagency working group has just released its updated Technical Support Document (TSD) on the social cost of carbon (SCC).

This is joyous news in some circles. “The ‘Social Cost of Carbon’ Is Almost Double What the Government Previously Thought,” Climate Progress enthuses. Why are they pleased? Because the higher the SCC, the stronger the (apparent) case for suppressing the production and export of hydrocarbon energy in general, and for blocking the Keystone XL pipeline in particular.

SCC is an estimate of how much damage an incremental ton of carbon dioxide (CO2) emissions does to humanity and the biosphere. SCC estimates are driven by assumptions about such issues as climate sensitivity (how much warming results from a given increase in CO2 concentrations), climate impacts (how warming will affect weather patterns and sea-level rise), economic impacts (how changes in global temperature, weather, and sea-level rise will affect agriculture and other climate-sensitive activities), and technological change (how adaptive capabilities will develop as climate changes).

Modelers feed the assumptions into computer programs called “integrated assessment models” (IAMs). By tweaking those values, the modeler can get pretty much any result he desires. Outcomes also vary based on the discount rate selected, i.e., how much people are assumed to value income in the future compared to income in the present.

Using three IAMs, three discount rates (2.5,% 3,% and 5%), and a fourth value representing low-probability catastrophic impacts, the interagency group calculates four SCC estimates for the year 2020. In the working group’s 2010 TSD, the SCC estimates were $7, $26, $42, and $81 (2007$). In the updated TSD, the corresponding estimates are $12, $38, $58, and $129 (2007$). Excuse me, but even for the high-impact projections, the updated estimate ($129) is 59% higher than the 2010 estimate ($81), which is more than a tad shy of “almost double.”

Let’s cut to the chase. Those who say the SCC is bigger than the government previously thought merely recycle the old saw that climate change is “worse than scientists previously thought.” They are mistaken. The climate change outlook is better than we have long been told.

One reason the updated estimates are higher is that the IAMs contain an “explicit representation” of sea-level rise “dynamics.” Are the modelers keeping up with the scientific literature? Consider two recent studies

  • King et al. (2012): The rate of Antarctic ice loss is not accelerating and translates to less than one inch of sea-level rise per century.
  • Faezeh et al. (2013): Greenland’s four main outlet glaciers are projected to contribute 19 to 30 millimeters (0.7 to 1.1 inches) to sea level rise by 2200 under a mid-range warming scenario (2.8°C by 2100) and 29 to 49 millimeters (1.1 to 1.9 inches) under a high-end warming scenario (4.5°C by 2100).

If 21st century sea-level rise is more likely to be measured in inches rather than feet or meters, shouldn’t SCC estimates decline?

And what about the 15-year period of no-net warming, which the climate science establishment did not predict and still struggles to explain? The warming pause is hard to square with the mantra of “worse than we thought.” It is evidence that the SCC is lower than they thought.

Let’s look at the disconnect between what they predicted and what happened.  The graph below comes from NASA scientist Roy Spencer:  [click to continue…]

Hurricane Sandy and Global Warming

by Marlo Lewis on November 2, 2012

in Features

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Both the blogosphere and the mainstream media have been abuzz with commentary blaming global warming for Hurricane Sandy and the associated deaths and devastation. Bloomberg BusinessWeek epitomizes this brand of journalism. Its magazine cover proclaims the culpability of global warming as an obvious fact:

Part of the thinking here is simply that certain aspects of the storm (lowest barometric pressure for a winter cyclone in the Northeast) and its consequences (worst flooding of the New York City subway system) are “unprecedented,” so what more proof do we need that our fuelish ways have dangerously loaded the climate dice to produce ever more terrible extremes?

After all, argues Climate Progress blogger Brad Johnston, quoting hockey stick inventor Michael Mann, “climate change is present in every single meteorological event.” Here’s Mann’s explanation:

The fact remains that there is 4 percent more water vapor – and associated additional moist energy – available both to power individual storms and to produce intense rainfall from them. Climate change is present in every single meteorological event, in that these events are occurring within a baseline atmospheric environment that has shifted in favor of more intense weather events.

Well sure, climate is average weather over a period of time, so as climate changes, so does the weather. But that tautology tells us nothing about how much — or even how — global warming influences any particular event. Moreover, if “climate change is present in every single meteorological event,” then it is also present in “good” weather (however defined) as well as “bad.”

Anthony Watts makes this criticism on his indispensable blog, noting that as carbon dioxide (CO2) concentrations have risen, the frequency of hurricanes making landfall in the U.S. has declined.

The US Has Had 285 Hurricane Strikes Since 1850: ‘The U.S. has always been vulnerable to hurricanes. 86% of U.S. hurricane strikes occurred with CO2 below [NASA scientist James] Hansen’s safe level of 350 PPM.’

If there’s anything in this data at all, it looks like CO2 is preventing more US landfalling hurricanes.

Data Source: NOAA; Figure Source: Steve Goddard [click to continue…]

John Christy on Summer Heat and James Hansen’s PNAS Study

by Marlo Lewis on August 20, 2012

in Blog, Features

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In a recent study published in Procedings of the National Academy of Sciences (PNAS), NASA scientist James Hansen and two colleagues find that whereas “extremely hot” summer weather “practically did not exist” during 1951-1980, such weather affected between 4% and 13% of the Northern Hemisphere land area during 2006-2011. The researchers infer that human-caused global warming is “loading” the “climate dice” towards extreme heat anomalies. They conclude with a “high degree of confidence” that the 2003 European heat wave, the 2010 Russian heat wave, and the 2011 Texas-Oklahoma drought were a “consequence of global warming” and have (as Hansen put it in a recent op-ed) “virtually no explanation other than climate change.”

In a recent post, I reviewed studies finding that the aforementioned anomalies were chiefly due to natural variability. In another post, I summarized an analysis by Patrick Michaels and Chip Knappenberger, who conclude that “the 2012 drought conditions, and every other [U.S.] drought that has come before, is the result of natural processes, not human greenhouse gas emissions.”

But what about the very hot weather afflicting much of the U.S. this summer? Greenhouse gas concentrations keep rising, heat spells are bound to become more frequent and severe as the world warms, and the National Oceanic and Atmospheric Administration (NOAA) reports that July 2012 was the hottest July ever in the U.S. instrumental record. Isn’t this summer what greenhouse warming “looks like“? What else could it be?

University of Alabama in Huntsville (UAH) climatologist John Christy addressed these questions last week in a two-part column. In Part 1, Christy argues that U.S. daily mean temperature (TMean) data, on which NOAA based its report, “do not represent the deep atmosphere where the enhanced greenhouse effect should be detected, so making claims about causes is unwise.” A better measure of the greenhouse effect is daily maximum temperature (TMax), and TMax records set in the 1930s remain unbroken. In Part 2, Christy argues that Hansen’s 10% estimate of the portion of land affected by extreme heat during 2006-2011 shrinks down to 2.9% when anomalies are measured against a longer, more representative climate baseline.  [click to continue…]

Is Gov. Perry ‘Anti-Science’? (Updated, Sep. 14, 2011)

by Marlo Lewis on September 9, 2011

in Blog, Features

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During this week’s GOP presidential candidates debate in California, Texas Gov. Rick Perry made a statement about global warming that Mother Jones, the Huffington Post, the UK Guardian, and others condemn as “anti-science.” Asked by moderator John Harris of Politico “which scientists” are “most credible” in questioning “the idea that human activity is behind climate change,” Perry replied:

Well, I do agree that there is – the science is – is not settled on this. The idea that we would put Americans’ economy at – at- at jeopardy based on scientific theory that’s not settled yet, to me, is just – is nonsense. I mean, it – I mean – and I tell somebody, I said, just because you have a group of scientists that have stood up and said here is the fact, Galileo got outvoted for a spell. But the fact is, to put America’s economic future in jeopardy, asking us to cut back in areas that would have monstrous economic impact on this country is not good economics and I will suggest to you is not necessarily good science. Find out what the science truly is before you start putting the American economy in jeopardy.

The UK Guardian was quick to denigrate Perry’s answer:

It’s one thing to question the economic impact and legacy of current climate policy proposals – you would expect and wish for politicians to debate this – but for a politician to question the science in this way is striking. . . .Note how he studiously ignored the moderator’s well-crafted question: who exactly are these “Galileos” that you believe have so comprehensively cast doubt on the canon of climate science? Perry couldn’t – or wouldn’t – name them.

The Guardian makes a mountain out of a molehill. If Harris was so keen to know which climate scientists Perry finds most credible, he could have just restated the question. Perry was apparently more interested in making two basic points: (1) he does not view global warming as a warrant for imposing massive new regulatory burdens on the U.S. economy; (2) he is not impressed by appeals to an alleged “scientific consensus” because, after all, scientific issues not settled by counting heads.

The question Harris asked is bound to come up again and again in candidate forums, and it’s a bit of a loaded question at that. Alarmists would like us to believe that any human contribution to climate change constitutes a “planetary emergency” (Al Gore’s phrase) and, as such, justifies the imposition of cap-and-trade and other assaults on affordable energy. Hence, they would like nothing better than to trick opponents into arguing as if the case against cap-and-trade, or against EPA’s hijacking of climate policy, hinges on the implausible thesis that greenhouse gases do not have a greenhouse (warming) effect.

How then should presidential contenders respond to such questions? [click to continue…]