Solar Geoengineering: The Most Effective Way To Fight Climate Change?

Given that humans are pumping 60-times more carbon dioxide gas into the Earth’s atmosphere than all of the planet’s volcanoes combined, would solar geoengineering be a viable method to limit global warming rise to 2-degrees Celsius?

By: Ringo Bones

Even if we manage to halt all of our production of carbon dioxide tomorrow, it would take quite awhile for overall carbon dioxide gas concentrations in our atmosphere to return to pre-industrial levels. In an interview back in July 9, 2012, the 1984 Nobel Physics Prize laureate Carlo Rubbia stated that based on what we currently know on the behavior of gaseous carbon dioxide currently circulating in the Earth’s atmosphere, the average lifetime that the carbon dioxide generated by human activity – as in biomass and fossil fuel burning – stays in the atmosphere before being sequestered back into wood and dissolved into the world’s oceans and lithosphere, is 30,000 years. Therefore most of the carbon dioxide produced when Emperor Nero burned a section of Rome as he fiddled around 2,000 years ago is still in our atmosphere. Given the relatively long delay time of removing excess carbon dioxide from our atmosphere, are there other more effective ways to halt the average global temperature rise to within 2-degrees Celsius by the year 2100?

Professor of Physics and Public Policy at Harvard David Keith suggests a method which he calls solar geoengineering. Despite of the risks, due to our still limited understanding of the planet Earth’s overall climate system, there are aspects of solar geoengineering that is directly modeled after recent climatic events and how it can be implemented for our overall benefit. Professor Keith suggests mimicking how volcanic eruptions trigger a global cooling effect for a number of years after the event. We could manage to keep the inevitable temperature rise to within 2-degrees Celsius by the year 2100.

Remember when Mt. Pinatubo erupted back in June 1991? It manage to lower overall global temperature by 2-degrees Celsius and another unforeseen consequence of the volcanic eruption was the resulting increased farm and ecosystem productivity that happened two years after the event. And according to Professor Keith, solar geoengineering could mimic such natural phenomena by flying jet planes to the stratosphere at the near equatorial region and spraying sulfur dioxide gas to produce sulfuric acid ice crystal clouds in order to increase planet Earth’s albedo – i.e. the reflectivity – of the Earth’s atmosphere reflecting excess infrared energy our planet receives from the Sun back into space. The planet Venus’ naturally occurring sulfuric acid ice crystal clouds is the reason why it has a higher albedo in comparison to planet Earth and this its “brighter” appearance in comparison to its sister planet. Although there are unforeseen risks involved due to our still limited understanding on how our planet’s climate system works and the formidable logistics involved of using a fleet of our current jet aircraft to produce sulfuric acid crystal clouds of similar density of that created by the Mt. Pinatubo eruption around the Earth’s equator, it seems that it is the only scheme that could produce a plausibly desirable result when it comes to keeping overall global temperature rise to within 2-degrees Celsius by the year 2100.