Climate Myths and Questions, Part III

In this final part of our three-part series, we examine sea ice extent, extraterrestrial warming, IPCC errors, and hacked e-mails. The topics we've covered this week just scratch the surface, of course; there are many more questions that people have over the evidence supporting the notion that human activities are causing global warming. We will likely return with another series in the near future, but in the meantime, I preface this installment with the same caveat that applied to the first two:

The topics tackled in this series by no means provide a comprehensive list; for such a list, I thoroughly recommend repeated visits to Skeptical Science, which addresses a great many more climate myths than we have room for here. Other excellent outlets include RealClimate and Climate Progress;  and New Scientist magazine also compiles an ongoing and regularly updated "guide for the perplexed." Each of the entries in this particular blog are, through necessity induced by the requirement for brevity, mere thumbnails; each contains links to background information that paints a broader picture.

Global sea ice levels are not decreasing.

There's an element of almost-truth to this, but the conclusions that are then drawn from it tend to be widely erroneous. The rationale for the argument is that, although summer sea ice in the Arctic is decreasing in extent, in the Antarctic it is not, and in recent years on average has in fact increased slightly (although it has declined significantly in some areas, specifically around the Antarctic Peninsula).

However, the fact that Antarctic sea ice extent has not decreased in total is actually not a surprise. The reason is that Antarctic and Arctic sea ice behave very differently.

Antarctica is a continent surrounded by water. Every summer, the great majority of sea ice breaks up and drifts north, where it melts. The Arctic, however, is an ocean surrounded by continents. There is only one major artery through which sea ice can escape; as a result, although obviously there is summer melting, much of the sea ice survives each summer and becomes progressively thicker. That is why the summer sea ice extent in the Arctic is of such interest; once that starts to diminish, that means there is less ice to provide a basis for winter ice growth, which in turn means there is less to survive the following summer, and so on. Whereas mostly sea-ice free Antarctic summers are not unusual, sea-ice-free Arctic summers would be unprecedented during human history.

The Antarctic is substantially colder than the Arctic; because most summer sea ice disappears anyway, it would require a much more significant warming than has yet occurred to cause winter sea ice to diminish. What is interesting, however, is the overall increase in recent years. This is not, aas some denialist commentators have asserted, a sign of cooling: in fact Southern Ocean temperatures have been increasing (opens PDF). So what's going on? Partly, it is a function of ocean circulation: As temperatures increase, so does precipitation, which freshens the surface layer of the ocean,l reducing mixing with lower layers and preventing transport of warmer, deeper water to the surface. And then there is the ozone hole, which causes cooling in the stratosphere, affecting atmospheric patterns in such a way that it likely contributes to increased sea ice. Ironically, the closing of the ozone hole over the coming decades may thus ultimately contribute to diminished sea ice extent.

There is global warming on Mars and Pluto too, which proves the warming on Earth has nothing to do with us.

The notion that the Sun is responsible for all planetary warming - on this and other planets - is the key claim of Russian scientist Habibullo Abdussamatov, who insists that the Sun is the sole determinant of temperature changes on Earth, and that our planet faces a period of prolonged cooling, not warming. Abdussamatov rejects even the existence of the natural greenhouse effect, a position that could generously be described as out of the mainstream. Abdussamatov finds support for his contention in recent observations of shrinking of the carbon dioxide ice cap in the southern polar region of Mars. More recently, observations of warming on Pluto have been used to bolster the contention.

Abdussamatov's theories are not taken  seriously by the vast majority of scientists, some of whom have called them "nuts" and said they "don't make physical sense." 

It certainly doesn't follow, as Abdussamatov has declared, that "these parallel global warmings ... can only be a straightline consequence of the effect of the one same factor: a long-time change in solar irradiance."

The two biggest problems are that (a) a half-dozen or so of 100 bodies in the Solar System are undergoing observable warming, while Uranu, for example, is apparently cooling; and (b) over the last 35 years or so, the Sun has in fact been undergoing a slight cooling trend.

This suggests that, as with Earth, any warming on Mars or Pluto must be related to conditions specific to those particular planetary bodies.

It has been suggested, for example, that any warming in Mars may be the result of orbital wobbles, or may be regional in nature. It is possible that winds have swept some of the surface clear of red dust, darkening it and descreasing its albedo effect. Some satellite data has suggested the changes in the ice cap may not be due to warming at all, but the result of normal, cyclical variations.

Pluto, however, does appear to have been warming, an observation that had astronomers scratching their heads because it was first observed 14 years after the then-planet passed within its closest point of the Sun during its 248-year orbit. Recent discoveries of methane in Pluto's atmosphere and on its surface suggest that what may happen is that, as Pluto closes on the Sun (relatively speaking), some of the frozen methane on its surface may warm enough to turn into a gas - which, because methane is a potent greenhouse gas, would cause further warming until the dwarf planet once again heads into the farthest reaches of the Solar System.

The temperature record is unreliable; there's no evidence it's really warming at all.

This criticism stems primarily, but not exclusively, from two main claims: That surface temperature stations in the United States have been located next to air conditioning units, in asphalt parking lots, on hot rooftops ... all the kinds of places that are going to provide disproportionately high temperature readings. However, while it is indeed extremely important that temperature stations be established in as appropriate sites as possible, and efforts to find inappropriate locations are laudable, analysis of the data undercuts the assumption that these poorly-situated weather stations are exaggerating warming trends. In fact, a comprehensive 2010 study found the opposite: that the poorly situated weather stations on average recorded maximum temperatures that were cooler than the "good" stations. The reason for that, it seems, is that those that are located in the best locations tend also to be more accurate and of higher quality. 

Some also continue to assert that atmospheric readings from satellites and balloons do not record warming. This did indeed appear to be the case until an independent reanalysis of tropospheric data  caused a readjustment; satellite data now shows warming since 1998 and this past January was in fact the warmest in the satellite record. (And this February was the second warmest February on record).

Additionally, sea surface temperatures, ocean temperatures, ice core reconstructions, and bore hole reconstructions all also show clear evidence of warming temperatures.

The shallowness of the science is exposed by the fact that the "alarmists" used to call it global warming, and now they call it "climate change" because they know the evidence shows warming isn't occurring.

Not, I'll admit, one of the stronger arguments. But it crops up from time to time, is clearly passed lazily around the blogosphere, and warps a factual kernel, so on balance it is worth commenting on.

This is a typical example of the genre: A claim that global warming is "now" called climate change, and that the change has been made "recently" because Earth is supposedly cooling. (It is never stated exactly when this change supposedly occurred; the implication is frequently made that someone - Al Gore or Michael Mann perhaps - sent the rest of us an e-mail with our new orders). "“Global warming” obviously entails global average temperature increase, whereas “climate change” is about much more than just temperature," froths the author of the afore-linked-to piece, who actually styles himself a climate change and energy policy analyst. But climate change science is about a lot more than increased temperatures, as even a casual reading of the most widely-available literature would revel. Climate change is the preferred term for precisely that reason. As this post points out, the issue was being called "inadvertent climate modification" by at least some as far back as 1970, and the first use of the term "global warming" was in the 1973 movie Soylent Green. (Spoiler alert: It's people. Soylent Green is people.) The first scientific use of the term was in a 1975 paper that also used a variation of "climate change," entitled "Climatic Change: Are we on the brink of a pronounced global warming?"

(Interestingly, it has been suggested that conservative pollster Frank Luntz encouraged the use of "climate change" instead of "global warming" because it sounded less alarming).

The fact that this claim has gained any traction at all points to an amazing capacity for intellectual laziness. After all, the international body charged with collating climate change science isn't the Intergovernmental Panel on Global Warming, and it never was. It is called the Intergovernmental Panel on Climate Change, and it has been since it was formed in 1988.

The IPCC reports are full of errors and lies. The Himalayan glacier fiasco proves it.

There is no point denying that the unfounded claim, included in the most recent IPCC Assessment Report, that Himalayan glaciers would mostly disappear by 2035, was, at the very least, embarrassing. It was a black eye for the IPCC - and, by extension, climate science - at a time when such a thing was least affordable. But it is important to put it in context.

Although this erroneous statement was included in one of the chapters of the IPCC report, it was not the official projection of the IPCC regarding glacier retreat, which is contained in this chapter of the assessment report, as well as in this one (both links open PDFs). Nor has the statistic been cited in any of the books based on IPCC findings. It was one error, that should not have been included, in an assessment report 3,000 pages long. It was the result, not of poor scientific research, but of including a non-peer-reviewed assertion in a process that relies on extensive peer review. The figure was, in fact, criticized by other scientists; the initial response of the IPCC chairman was unnecessarily and inappropriately defensive, but the flap does nothing to affect the volumes of observations,  by a wealth of researchers, that glaciers are indeed in retreat around the world in line with climate models.

It's all a conspiracy; the e-mails prove it.

Ah yes. The newest entry to the canon, and the deniers' new favorite: the leaked (or, if you prefer, hacked) e-mails from the Climatic Research Unit of the University of East Anglia prove that climate scientists have been making the whole thing up.

But examination of the e-mails shows they do not, in fact, point to a vast conspiracy or even undermine the science behind climate change in any way. There was no attempt to "hide" any "declines" in temperatures; there was no secret hand-wringing over global warming having stopped; editorial board members resigned from a climate journal not because of threats from CRU and other scientists, but because the content and quality of the paper those scientists had excoriated was so poor that the editorial board members felt it showed the journal's peer-review process had broken down; far from being excluded, two papers that were highly criticized in the e-mails were included in the IPCC's fourth assessment report.

Going through all the claims about the e-mails would require a post all to itself; fortunately, others have already provided excellent contextual explanations, including RealClimate, the Union of Concerned Scientists, and the Pew Center on Global Climate Change (opens PDF). An Associated Press analysis found that while some of the content of the e-mails isn't pretty, the fundamental scientific consensus about climate change is unaffected.

If only the e-mailers had used language more appropriate to scientific discourse, some might say; if only they had said things like, "Let's figure this all out based on good, careful work and see what the data has to say in the end," or "Let's let [the differences] play out the way they are supposed to, objectively, and in the peer reviewed literature," or  “We have to make sure we stick to only the best science.” If only they had written those things, then there wouldn't have been any controversy, right? Ah, but they did, as Pete Altman found after poring through the documents. Strangely enough, those who pounce on the e-mails as evidence of nefarious wrongdoing have not chosen to include any of this correspondence. Had just these e-mails been selectively quoted, the "story" would have been far different.

Even allowing ourselves for a moment the fantasy that the scientists involved in "Climategate" somehow conspired to falsify data and lead the world down a garden path, it means nothing. Carbon dioxide IS a greenhouse gas; that is a fact. It IS increasing in the atmosphere and its increase is identifiably linked to the burning of fossil fuels. Observations - not just of temperature increases, but also ecological and other natural system responses to temperature increases - are meeting or exceeding predictions. Global air temperature, humidity and rainfall trend patterns exhibit a distinct fingerprint that can only be explained by increased atmospheric greenhouse gas concentrations.

The evidence is voluminous, comprehensive, and conclusive.

Global warming is real, and climate change is happening.

Would that it were not. But it is.

(Images used in this series from RealClimate, Intergovernmental Panel on Climate Change, Skeptical Science, Scripps Institution of Oceanography, NASA, University of Illinois at Urban-Champaign Polar Research Group/The Cryosphere Today, Global Warming Art Project)