Critical Times

by Renfrey Clarke

If the Weekend Australian devotes a whole broadsheet page to a proposed solution to global warming, the editors must want to inform the public on how best to combat climate change. Right?

Hardly. If the Weekend Australian cared about our climate, it wouldn’t draw its text from one of the strangest travesties of climate science ever to issue from a printing press.

Besides, a page of space in a national newspaper is worth big bucks, and Rupert Murdoch’s News Corporation usually doles out serious news of climate change in column-millimetres. No, the Weekend Australian will be trying to sell a message aimed at enhancing the bottom lines of the big-business interests for which the Murdoch papers speak.

So what was the underlying message of the article Heat is on global warming, carried by the Weekend Australian on October 24-25? Briefly, don’t dream of cutting into corporate profits so as to reduce carbon emissions. If the talk of global warming turns out to be true (and the paper, as usual, stresses its doubts here), there’s a simpler, cheaper option: cool the Earth by running a hose up to the stratosphere, suspended by balloons, and pumping sulphur dioxide into the upper atmosphere.

Improbably, this idea has a scientific basis. And so dire have the prospects for the global climate now become, that highly regarded climate scientists are suggesting that a resort to such “geoengineering” may be unavoidable, if only to restrain warming until conventional emissions abatement has time to work.

That would be a balanced and frank assessment. The article in the Weekend Australian, by contrast, is like something out of Monty Python: an edited extract from the new book Superfreakonomics: Global Cooling, Patriotic Prostitutes and Why Suicide Bombers Should Buy Life Insurance, by Steven D. Levitt and Stephen J. Dubner.

The article makes unpleasant reading, and not just because of its brash prose style. US economists Levitt and Dubner use the whole gamut of journalistic tricks to imply falsely that climate scientists – in particular, the renowned Ken Caldeira of the Carnegie Institution at Stanford University – discount the importance of human agency in causing global warming.

Worse, Levitt and Dubner openly deny the science by claiming that warming has somehow stopped: “…while the drum-beat of doom has grown louder in recent years, the average global temperature has in fact decreased.” When the whole of the earth’s climate system – including polar regions and the ocean subsurface – is taken into account, the results show conclusively that warming has continued.

But what’s this about sulphur? A key reason why global warming has not proceeded much faster is that the effect of greenhouse gases has been “masked” by tiny particles, referred to collectively as aerosols, in the atmosphere. The net effect of aerosols is to increase the earth’s reflectivity, and raise the amount of energy from the sun that is radiated back into space.

Some of the best energy reflectors are sulphate particles – minute droplets of water and sulphuric acid. These result mostly from the chemical transformation of the gas sulphur dioxide, one of the pollutants released when coal is burned. Another important source of sulphur dioxide is volcanic eruptions.

There is no doubt that adding sulphur dioxide to the atmosphere would cool the planet. In June 1991 Mount Pinatubo in the Philippines exploded, shooting some 20 million tonnes of sulphur dioxide into the upper atmosphere. Global surface temperatures dipped temporarily by about 0.5ºC, close to the increase since pre-industrial times.

Sulphur dioxide is the main source of acid rain, a serious environmental problem. But if injected into the stratosphere more than nine kilometres up, sulphur compounds stay in place for as long as several years, versus a few weeks at lower levels. The amounts needed to reduce global temperatures would in this case be minor compared to existing low-altitude sulphur pollution. The costs, the Wall Street Journal surmised on June 15 this year, would be relatively cheap, “just a few billion dollars a year.” Initially, the releases could be concentrated in the Arctic where warming has been greatest.

Just a few billion dollars, to make climate activists shut up? The idea of treating the upper atmosphere with sulphur has been seized on by right-wing US media organs such as The National Interest and National Review.

It is a mark of the seriousness of the climate threat that reputable scientists, such as Caldeira and Dutch Nobel prizewinner Paul Crutzen, have addressed the concept too. The scientists’ general verdict is that while research on the proposals should continue, there is a clearly identifiable downside, and “unknown unknowns” – the potential for unanticipated, catastrophic outcomes – mean that the risks are formidable.

One risk that is relatively well understood is that of ozone depletion. The ozone layer in the upper atmosphere protects the earth’s surface from harmful cosmic rays. After the Pinatubo eruption ozone levels, already reduced by human-caused pollution, were observed to dip still further. In 2008 a study led by Simone Tilmes of the (US) National Center for Atmospheric Research, and reported in Wired Science News, concluded that the volume of sulphate particles needed to reverse the warming caused by a doubling of atmospheric carbon dioxide would “destroy much of the Arctic’s ozone layer; delay recovery of Antarctica’s current ozone hole; and cause ozone thinning in mid-latitude regions.”

Serious impacts on polar biosystems, as well as large numbers of human cancers, could be expected to result.

Meanwhile, the effects which a rapid, pronounced cooling might have on world rainfall patterns are not well understood. Would it weaken the monsoons in South and East Asia? If this were the case, famines could kill millions of people. And what would be the effect on plants of reducing the amount of direct sunlight, in favour of diffuse radiation scattered by sulphur aerosols? There is speculation that growth of many plants would be restricted, lowering their uptake of carbon dioxide and speeding the rise of atmospheric carbon levels.

Putting sulphur dioxide into the stratosphere, in any case, would simply offset the warming caused by carbon pollution; it would not counteract the other effects. Rising levels of carbon dioxide would still make the oceans more acidic, wreaking havoc with food chains and potentially, wiping out much of the Earth’s marine life.

And what if “unknown unknowns”, unanticipated but perilous, were to force authorities to turn the sulphur dioxide hoses off? The carbon would still be in the atmosphere, and within a few years would raise temperatures to the point they would have reached without geoengineering measures. What would be the effects on the environment of a more-or-less- instantaneous rise of global average temperatures, perhaps by several degrees? That, perhaps, is the biggest unknown of all.

Against the uncertainties of geoengineering, scientists are forced to weigh the relatively well-understood catastrophes promised by the build-up of greenhouse gases. Most apocalyptic, perhaps, is the serious prospect of rapid Arctic warming setting off a vast pulse of methane gas from melting permafrost. Measured on a time scale of 20 years (rather than the usual, but less relevant, 100 years), methane has conventionally been reckoned to have 72 times the global warming effect of carbon dioxide. Recent research, however, suggests that when the interaction of methane with aerosols is taken into account, the actual effect could be a third stronger.

In the face of dangers such as these, to fail to research ways of artificially cooling the Arctic could be gravely irresponsible – known and unknown risks notwithstanding.
The choices before humanity are indeed diabolical. But amid the irrelevancies, mangled science and out-of-context quotes of the Weekend Australian’s article, one looks in vain for any sense of the true depth of our climate dilemma. There is no mention of methane, or of ocean acidification. Ozone depletion is mentioned only as the topic of the research that won Crutzen his Nobel prize. For Levitt and Dubner, the whole question of halting climate change is reduced to the following:

“Once you eliminate the moralism and the angst, the task of reversing global warming boils down to a straightforward engineering problem: how to get 155 litres of sulphur dioxide a minute into the stratosphere. ”

The scientists, it is clear, could hardly disagree more. Again and again in their web discussions, the point is reiterated: geoengineering is much too risky to be used as anything except a last resort, in circumstances where catastrophe would otherwise be near certain.

The first choice has to be a much more determined pursuit of carbon mitigation. Here, for example, is Paul Crutzen’s conclusion in a 2006 essay for the journal Climatic Change:

“…the very best would be if emissions of the greenhouse gases could be reduced so much that the stratospheric sulfur release experiment would not need to take place.”

Even Nathan Myhrvold, a researcher of sulphur-release technology who is quoted voluminously by Levitt and Dubner, is reported as insisting in an October 2009 Superfreaks blog post:

“Geoengineering is proposed only as a last resort to try to reduce or cope with the even greater harms of global warming.”

Ken Caldeira, interviewed for Yale Environment 360 on October 22, goes so far as to attack Levitt and Dubner for grossly misrepresenting his views. In their book, the two have Caldeira maintaining that “carbon dioxide is not the right villain” in the fight to stop global warming.

“I don’t believe I said anything remotely like that,” Caldeira told the Yale interviewer, “because I believe that we should be outlawing the production of devices that emit carbon dioxide, and I don’t think we can solve this climate problem unless we drastically reduce our carbon dioxide emissions very soon.”

For their overall cavalier handling of scientific facts, Levitt and Dubner also meet with a ferocious drubbing in a mid-October post by the (US) Union of Concerned Scientists.

The scorn and indignation of the scientists was evident days, at least, before the Weekend Australian unleashed the maunderings of Levitt and Dubner on the Australian public. Plainly, the Murdoch hacks do not care about scientific truth – or the eventual fate of humanity, for that matter. Their concerns are ideological and commercial.

However emphatically the scientists rebuke Levitt and Dubner, it could be argued that these critiques miss the main danger in the current push for geoengineered “solutions”. This danger arises from the fact that capitalism and geoengineering, when combined, have a runaway dynamic reminiscent of climate change itself. Where global cooling schemes are pursued in a capitalist context, failure is implicit in success; to the extent that temperatures are actually reduced, corporate polluters are bound to seize on the sense that the dangers are receding, and will demand to be allowed to continue their carbon emissions.

As the gains from geoengineering are consumed by rising carbon dioxide levels, still more radical and dangerous technofixes will be touted. Like global cane toads, the “solutions” will become menaces to dwarf, perhaps, even the original problem.

A rational society, one not driven by the imperatives of corporate profit, would focus its ingenuity on reducing carbon emissions in the first place. Carbon dioxide already in the atmosphere would be drawn down through methods like reforestation and soil carbon sequestration. Geoengineering methods would be explored, but kept in reserve as insurance against the crossing of climate “tipping points” and the onset of runaway warming.