Dimming the sun as an emergency brake against climate change?

Global warming continues: the year 2020 ranks first as the warmest year ever measured. As the effects of climate change become more and more profound, the call for solutions sounds louder. And so it also looks at the role of technology.

American science journalist Elizabeth Kolbert traveled the world and talked to scientists who are developing or already applying techniques. Geo-engineering, or tinkering on the climate, will increasingly be a serious option, says Kolbert in an interview with Nieuwsuur. โ€œWe humans have had a huge impact on the planet. The question of how now is the question of our time. There are no easy choices.โ€

By far the most extreme intervention is the dimming of the sun. That could, at least in theory, be possible by imitating a volcanic eruption. With such an eruption, large amounts of sulfur are released. These dust particles, like a blanket, block the sunlight, like in 1991 in the Philippines.

Large eruptions can lead to temporary temperature drop worldwide. Researchers from Harvard University, among others, study whether sulphur dioxide dumped into the stratosphere by aircraft have the same effect.

A first preparatory experiment with solar engineering that would take place in Sweden this summer has been cancelled following protests from environmental organisations, among others. Kolbert: โ€œThey fear that such simple solutions will be at the expense of motivation to reduce CO2.โ€

Accidental effects

The use of technology to influence the climate system is surrounded by diabolical dilemmas, notes Kolbert. โ€œMan has changed the climate through the use of fossil fuels. And now we want to take further action to undo earlier intervention.โ€

The science journalist thinks that we are increasingly faced with the choice of whether or not to use certain techniques. โ€œOne of the people involved in the dimming of the sun said to me: We live in a world where it is now safer to dim the damn sun than not to. I found that significant.โ€

Solar engineering is still in its infancy. But we cannot avoid seriously considering these and other techniques, thinks Behnam Taebi, Professor of Energy and Climate Ethics at Tudelft. โ€œWe have passed the station where we can afford the luxury to say: we dont, because thats too risky.โ€

National Centre of Expertise

Taebi stresses that there are no concrete plans for solar engineering. โ€œBut I would like to deal with the question of responsibility at the front. Instead of first things go wrong and then we ask: who is actually responsible for this?โ€

Together with a group of Dutch scientists, Taebi advocates setting up a national centre of expertise on climate interventions. This should focus on technical and ethical issues. โ€œA country can now decide to apply solar engineering independently. But the consequences are transnational. Agreements have yet to be made on that.โ€

Science journalist Kolbert wrote a book about her findings: Under a white sky, the nature of the future. She argues for more debate on climate interventions: โ€œI am not saying we should or should not do it. But they will be more and more pressing questions.โ€ Ethicist Taebi: โ€œNobody takes into account that technology alone can counteract global warming. We dont have such a big band-aid.โ€

CCEit on 3 previously made this explanation about geo-engineering: