The implementation of climate engineering technologies as a last ditch effort to combat the escalating effects of climate change could make things worse, according to a modelling study published in Nature Communications this week. The findings indicate that climate engineering is likely to be either relatively ineffective or to result in severe climatic side effects.
With the rate of climate change outpacing mitigation strategies, climate engineering as a potential means of preventing catastrophic climate change is attracting more and more interest. Climate engineering, also known as geoengineering, refers to man-made technologies specifically designed to manipulate global climate. While the potential effectiveness of individual methods has been tested, there have been few attempts to compare them.
David Keller and colleagues use an Earth system model to evaluate the effectiveness and potential negative side effects of five climate engineering technologies when deployed continuously, and at scales as large as currently deemed possible, under a high CO2-emission scenario. The team show that, even when several technologies are combined, climate engineering would be unable to prevent mean surface temperatures from rising well above 2° C by the year 2100. In addition, they show that all technologies are, individually, either relatively ineffective with limited warming reductions (less than 8%), or that they have potentially severe side effects and cannot be stopped without returning large amounts of stored CO2 to the atmosphere and causing rapid climate change.
The teams’ findings strongly suggest that climate engineering technologies should not be depended upon to prevent future warming and that CO2 mitigation is likely the most effective way to prevent further climate change. Additional studies, using more sophisticated models, are required to further our understanding.