Take geo-engineering seriously as an emergency brake to combat global warming

News - 20 April 2018 - Communication

Geo-engineering. The idea is cropping up increasingly often in answer to the question: what can we change on Earth to curb global warming? First and foremost, we must do everything we can to reduce emissions of greenhouse gases around the world. The Paris climate agreement is an important step in the right direction, but more and more studies are showing that the promises made by the signatory countries will have insufficient effect. So we need to find a quicker way to reduce greenhouse gas emissions but, unfortunately, the global community isn't prepared to do that just yet. At some point, we may need geo-engineering whether we like it or not. The sooner we carry out research into the practical aspects of geo-engineering, the possible pitfalls and the consequences, the better prepared we will be for the future.

Geo-engineering in the context of the fight against climate change is a relatively new research field. For a long time, it’s been hidden away in libraries and studies due to a real taboo on fiddling around with the Earth: that's simply not done! Despite this, though, we're now starting to see concrete developments. Students from TU Delft recently researched the practical aspects of a particular geo-engineering-option: the design of a new aeroplane to take aerosols into the stratosphere and a rough estimate of the costs. Every year, the planes would take five megatons of aerosols to altitudes of between 18.5 and 19.5 km. Theoretically, this would be enough to have a significant curbing effect on the amount of sunlight that reaches Earth and therefore on the temperature.

It's actually an imitation of an erupting volcano. This can lead to temperatures dropping globally, as was seen, for example, when Pinatubo erupted in the Philippines in 1991. It's one of the variants of Solar Radiation Management (SRM), shielding the Earth from sunlight to moderate the temperature. Another possibility is to ‘whiten’ the clouds by adding extra aerosols, a technique that is being cautiously explored.

Geo-engineering can be effective, but there are obviously risks too. For example, we still do not know enough about the impact it will have on the weather or our ecosystem. In addition, certain parties could use geo-engineering as a reason for doing less to tackle emissions of greenhouse gases. This would be counter-productive: geo-engineering is an emergency brake, not a solution. Very little attention has been paid to the administrative, legal and ethical aspects of geo-engineering. In other words: who’s allowed to control our climate?

We must take geo-engineering seriously and develop knowledge about the technology and the consequences, and about the ethics and modes of administration. Reducing greenhouse gas emissions must remain the priority, but the geo-engineering emergency brake should be in working order, should we ever need it. If we wait until then to develop it, we will be too late.

Professor Herman Russchenberg, director of the TU Delft Climate Institute