Apparently, Paul Crutzen, an environmental scientist who shared a Nobel Prize in 1995 for his work on the role of CFCs in ozone layer depletion, thinks we should correct for global warming by injecting two million tonnes per year of sulphate particles into the upper atmosphere. According to Wikipedia: “sulfates occur as microscopic particles (aerosols) resulting from fossil fuel and biomass combustion. They increase the acidity of the atmosphere and form acid rain.” He predicts that the process of injecting them into the upper atmosphere using balloons or artillery would cost between $25 and $50 billion a year, but would save more by mitigating the effects of global warming.
While I am no environmental scientist, what strikes me as most interesting about this is the ‘technical fix’ mindset that it embodies: a bit like those who decided to stabilize dune formation on parts of the Oregon coast by importing Spanish beach grass, or those who have sought to kill off one accidentally imported pest with an intentionally imported predator. Often, such schemes don’t work at all. When they do, they risk working much too well. Thanks to Spanish beach grass, the Oregon dunes will be a thing of the past in a few decades. The point is simply that, at a stage when we really don’t know the consequences of climate change or their magnitude, it seems awfully bold to predict that such a scheme will both work and do more good than harm.
As is so often the case, the most trenchant criticism of such schemes was expressed humorously on The Simpsons:
SKINNER: Well, I was wrong. The lizards are a godsend.
LISA: But isn’t that a bit short-sighted? What happens when we’re overrun by lizards?
SKINNER: No problem. We simply unleash wave after wave of Chinese needle snakes. They’ll wipe out the lizards.
LISA: But aren’t the snakes even worse?
SKINNER: Yes, but we’re prepared for that. We’ve lined up a fabulous type of gorilla that thrives on snake meat.
LISA: But then we’re stuck with gorillas!
SKINNER: No, that’s the beautiful part. When wintertime rolls around, the gorillas simply freeze to death.
The comparison between atmospheric science and ecology is less dubious than one might think. Both systems are complex and dynamic – they feed back upon themselves in ways which are both powerful and difficult to predict. Furthermore, both atmospheric and ecological systems both affect and are affected by other complex systems with which they are integrated. Consider, for instance, how the construction of the Aswan High Dam (the product of political and economic changes, above all) altered the salinity in the eastern Mediterranean, allowing for the migration of species from the Red Sea.
What would the consequences of blasting artillery shells full of sulfates into the upper atmosphere? Far be it for me to speculate. The intentional modification of atmospheric chemistry and physics is something we have never done as a species, though we have done a lot of unintentional tinkering. What I would venture is that it is likely to have unpredictable effects and that it is a particularly curious way of trying to deal with the problem of global warming.
George Monbiot, who I met at a short conference at the Environmental Change Centre, has his own objections.