Climate change: cloudy, with a chance of competing realities Blame the clouds?

Climate change: cloudy, with a chance of competing realities

By John Timmer | Published about 18 hours ago

Climate change: cloudy, with a chance of competing realities
Blame the clouds?

There's a quote attributed to Daniel Patrick Moynihan, which generally goes "Everyone is entitled to his own opinion, but not his own facts." Yet that's exactly what seems to have developed in the world of climate science. Within the mainstream scientific community, the basic physics that drives greenhouse warming hasn't been in dispute since it was discovered over a century ago, and the ability of greenhouse gasses to force climate change is apparent on other planets and within the Earth's past.

But there's an entire parallel community, one with a handful of its own scientists. There, any prediction of a measurable impact of climate change is considered unjustifiable alarmism; mainstream science is seen as colluding to stifle all countervailing evidence, as demonstrated by the e-mails stolen from the CRU.

(The multiple inquiries that have cleared the scientists who sent the e-mails? Under this view, they're little more than a whitewash.)

How have two communities ended up with what are essentially different facts? It's easy to understand some of the psychology behind it, as behavior that lets us selectively accept information based on things like our group identity has been studied extensively. But many of the differences go well beyond selective filtering. They seem to arise from an entirely separate collection of raw information.

A fatal blow?

A good example of how this sort of thing happens occurred last week. It started with the journal Remote Sensing, which recently published a paper by Roy Spencer, a former NASA scientist who is now based at the University of Alabama, Huntsville. Spencer's specialty is working with satellite data, but he's most notable as a prominent contrarian voice: he tends to ascribe the recent warming trends to factors other than greenhouse gasses.

This stance has made him quite popular within the community that labels itself "skeptics," and has led to a long relationship with a libertarian think tank called the Heartland Institute. That relationship has helped put Spencer on numerous news programs, and sent him to press conferences during major climate summits.
Roy Spencer

Spencer has written, "I would wager that my job has helped save our economy from the economic ravages of out-of-control environmental extremism," suggesting the boundary between his research and advocacy can be a bit blurred. But the mechanisms he uses to explain the earth's warming—he appears to view cloud cover as a forcing rather than a feedback—aren't widely accepted among the broader scientific community. In fact, his ideas have proven so unpopular within the scientific community that he has taken to advancing them via popular books instead of through scientific papers.

But Spencer apparently decided to give peer review another shot. His new paper suggests that, at least in the short term, some of the climate models in common usage overestimate the amount of heat that's trapped in the atmosphere by greenhouse gasses. That result was amplified by a University of Alabama press release, which was picked up by a number of blogs and later entered the mainstream media.

Perhaps the most significant coverage of the paper came at Forbes, which ran an online op-ed that was picked up by Yahoo News. The piece was penned by one of Spencer's colleagues at the Heartland Institute; its headline claimed that "New NASA Data Blow Gaping Hole In Global Warming Alarmism." Filled with dismissals of climate "alarmists," the editorial claims that the paper "should dramatically alter the global warming debate" because it shows that the climate models used by the IPCC are terminally biased towards exaggerating warming. Similar claims were apparently made ahead of Spencer's appearance on several talk shows.

If a person was exposed only to the claims being made in these outlets, it would be easy to conclude that Spencer had struck a blow, perhaps a fatal one, against the mainstream view of the climate.

Meanwhile, in the alternate reality...

The funny thing is that the paper says nothing of the sort. To begin with, it focuses on relatively short-term responses (under two years) to weather events, so its relevance to the long-term forecasts of climate isn't exactly clear, and isn't discussed in the paper. And, at least as far as the general trends, the satellite readings and climate models generally agree; Spencer's paper concludes that the climate's "behavior is also seen in the IPCC AR4 climate models."

There are differences, however, when the models are compared with satellite data in an attempt to determine the relative importance of climate forcings and feedbacks, but the paper interprets this cautiously: "While this discrepancy is nominally in the direction of lower climate sensitivity of the real climate system, there are a variety of parameters other than feedback affecting the lag regression statistics which make accurate feedback diagnosis difficult."

Spencer clearly considers this paper to support his larger contention—that clouds drive climate changes, rather than largely being a response to them—but he does not argue for it forcefully in the paper.

Depending on where people do their reading, it's possible for them to occupy two entirely separate scientific realities.

That caution was already slipping away in the press release, however, which claims that "Earth's atmosphere is apparently more efficient at releasing energy to space than models used to forecast climate change have been programmed to 'believe.'" Still, Spencer himself is quoted as saying that the system is too complex to allow the accurate separation between forcings and feedbacks, a conclusion in keeping with the one in his paper.

But even that limited conclusion hasn't been well received by mainstream scientists. Live Science contacted a number of people who are familiar with climate modeling, and they clearly don't think much of the research. In general, they found the simple model that Spencer uses in order to try to separate out forcings from feedbacks so overly simplified that it's unlikely to provide us with any valuable information. And they point out that short-term differences seen here might not accurately reflect the long-term changes that are the domain of the IPCC model projections. (One of the scientists contacted, Andy Dessler, has even published on the topic and shown that the models that get short-term cloud feedbacks right differ significantly in projecting long-term feedbacks.)

One of the scientists quoted has even performed a quick reanalysis of the data in the paper, which suggested that the accuracy of a model in Spencer's analysis is largely dependent upon the model's ability to handle the El Niño-Southern Oscillation, a short-term climate event.

Those who either looked in detail at the publication or tracked the online response to it might therefore come away with a completely different impression of what the paper said, and what it meant for the field as a whole. In short, it's not simply a matter of an audience selectively picking information; depending on where people do their reading, it's possible for them to occupy two entirely separate scientific realities. In one, the consensus view of greenhouse-driven climate change remains strong, while in the other, Spencer's paper joins a long list of results casting doubt on the conclusions of the IPCC.

Polarization

This has a way of being self-reinforcing. The climate community as a whole will continue to use these climate models because they've concluded that Spencer's paper really doesn't say anything significant about them.

To climate change critics, however, the continued use of existing models appear increasingly delusional, which will undoubtedly feed into some of the more extreme conspiracy theories that have sprung up regarding climate science. The fact that the mainstream press has largely ignored Spencer's paper won't be viewed as a sign that it was limited in its significance; instead, it will be viewed as a sign that the media's bias keeps it from covering any of the material that the self-labelled skeptics say indicates severe problems with climate science (something Ars has been accused of with regularity).

In the end, the availability of a completely alternate framework to interpret the field makes bridging the gaps in understanding between the two sides challenging. Most of the proposed solutions for increasing the public's literacy when it comes to climate change—primarily better education and outreach by a diverse community of scientists—don't really address the level of mistrust and misunderstanding that has piled up over the years.




Climate change can be forced by many factors, including changes in incoming solar radiation, changes in the amount of light the Earth reflects back into space, and changes in greenhouse gas concentrations. ( More... )