Researchers look to geoengineer a way out of global warming

In spite of the imaginings of climate deniers, the world is getting warmer with potentially catastrophic consequences. As politicians dither, climate researchers are not only talking about the weather, but also are considering doing something about it. They are exploring geoengineering solutions to mitigate global warming. But does the risk of geoengineering outweigh its benefits?

So what is geoengineering? Geoengineering can be defined into two broad categories: technologies that absorb carbon dioxide and address the root cause of global warming, and technologies that reduce solar radiation and address the effect of global warming.

Obviously, addressing the root cause of global warming is preferred. Simply planting more trees to absorb CO2 is a benign form of geoengineering that poses little risk. The problem with such a solution is that it might be too late to affect the rising temperature in reasonable timeframe. A more invasive method is to seed the oceans with iron. This would increase the production of phytoplankton, which, like forestation, would sequester carbon. But such changes of ocean chemistry could kill fish and produce other greenhouse gases such as methane.

Instead of reducing carbon dioxide, other technologies could be used to cool the planet by decreasing the solar radiation. One solution – inspired by the 1991 eruption of Mount Pinatubo in the Philippines that cooled global temperature nearly 1 degree in 1992 and 1993 – is to fire sulfates into the atmosphere. Mount Pinatubo emitted more than 15 million tons of sulfur dioxide. According to calculations by National Center for Atmospheric Research climate scientist Tom Wigley, “firing about half that much sulfur into the stratosphere every year for 30 years would help stabilize global warming's rise.” This solution, however, would not address other issues with increasing atmospheric carbon dioxide levels, such as ocean acidification. Moreover, the long-term health and environmental effects of permanently suspending sulfur dioxide in the stratosphere are simply unknown.

The best way to tackle global warming is to quit burning fossil fuels. But for practical and political reasons, substantial reductions in fossil fuel usage are unlikely. Geoengineering may offer solutions to some of the immediate effects of global warming, but its long-term ramifications could outweigh any benefits. Additionally, the availability of such solutions could increase complacency about reducing fossil fuel consumption. Like an obese person who wants a diet pill instead of doing the hard work of eating healthy and exercising, our addiction to oil and natural gas is motivating the search for a quick fix. Unfortunately, at this stage in the game, we may have little choice.