The risks of geoengineering

Projects to reduce the amount of heat the Earth receives from the Sun have been put forward as potential solutions to climate change. These geoengineering schemes include placing mirrors in space or putting particles in our atmosphere to reflect more of the Sun's rays. However, research by the Met Office shows relying on these methods instead of reducing carbon emissions is no easy solution.

Climate scientist Dr Olivier Boucher explains: “Geoengineering projects are not an ‘easy-fix’ solution to climate change if the world fails to reduce carbon emissions. Relying on artificial methods of cooling the atmosphere could be risky; tie us in for centuries of commitment, and would require far greater long-term cuts in greenhouse gas emissions in the future.

“If we rely on geoengineering to buy us time in reducing carbon emissions for anywhere from 10 to 40 years, we will be committed to those compensation projects for up to hundreds of years to offset the extra emissions.

“If you put CO₂ in the atmosphere it has a very long lifetime, and you are basically giving a poison gift to your children. By relying on geoengineering you are equally putting a burden on future generations to continue those projects — potentially for centuries.

“Geoengineering reliance would also have the effect of storing up issues over our greenhouse gas emissions. Even by using such projects, any delay cutting carbon emissions now would require much greater reductions in the future. To stabilise temperatures we would have to cut global carbon emissions to zero or even have negative carbon emissions.

“Ultimately if we carry on emitting carbon dioxide in the future, we would be committed to using geoengineering indefinitely. This could also cause problems because if they failed or were stopped too early the carbon in the atmosphere would take its effect, causing rapid climate change. Humans, wildlife and the environment would find it very difficult to adapt to the quick rise in surface temperatures.

“There are also a range of other concerns about geoengineering, which remains a speculative area of science. This includes issues about potential side effects and the difficulty in understanding how influencing the climate in this way would affect various aspects of the climate system.”

Dr Boucher concludes: “It is important that we continue research on the potential consequences of geoengineering strategies as long as they are being considered.”