Solar Geoengineering – Why we must dim the sun before entering the post-fossil age

Thomas Ramge

Humanity is not decarbonizing decisively enough. In a few decades from now, we will likely live on a planet with 2 degrees of global warming. Without solar geoengineering, billions of people will suffer unbearable consequences. Reflecting sunlight into space will be our best option to gain time.
Stage 10

Solar geoengineering is a taboo among politicians, scientists, and the Intergovernmental Panel on Climate Change. The blinkers must come off as quickly as possible. We will most likely have to dim the sun in fifteen to twenty years.

Let's face the facts. We are already living in a world with 1.5 degrees of warming. The climate tipping points are getting closer and closer. Humanity is not decarbonizing decisively. Everyone knows it, but no one says it openly: without geoengineering, humanity will struggle with the consequences of 2.5 or 3 degrees of warming in the second half of the century. For billions of people, especially in the Global South, it will be a struggle for survival. We should care now!

It is high time to give the debate on climate policy a new twist that explores geoengineering as a stopgap solution to gain time for the transition into a post-fossil age:

  • How solar geoengineering can technically work by injecting sulfur dioxide into the stratosphere (just like volcanos do once in a while)
  • What the risks and unknowns are and what kind of research is needed to mitigate these risks
  • Why we need a new global governance structure for geoengineering safeguarding the rights of climate-vulnerable countries
  • How we can make sure that geoengineering is not misused as an excuse to keep on burning fossil fuels
  • Why we should start this debate today if we care about a good life for all in 2050 

The talk will (of course) not present solar geoengineering as a techno-fix against climate change but present it as what it is:

Dimming the sun is the methadone program of carbon-addicted humanity. It's cheap and works quickly, but unfortunately, it doesn't offer a long-term solution. It does not address the causes of climate change. Instead, there is actually a risk of several adverse rebound effects. It would be great if humanity could forego solar geoengineering and get climate change under control before the world goes off the rails. But how likely is this in view of the fact that carbon dioxide emissions continue to rise year on year? In a realistic scenario, shading the Earth during a transition period can help us to finally move away from carbon and, at the same time, mitigate the dire climate consequences during the withdrawal phase – no more, no less. In the long term, we carbon junkies have to beat our addiction. 

This session is part of our focus topic on "freedom" as part of the Science Year 2024.

Porträt des Autors Thomas Ramge
Wissenschaftsautor und Podcasthost SPRIND