Manipulating the to defeat climate change, a good idea? – rts.ch

To deal with climate change, science is looking for solutions to sometimes cool the Earth, limit the effects of storms or cause artificial . Rather than fighting against global warming, should we adapt to it using technology?

Images of the floods in the Arab Emirates went around the world, accompanied by a rumor: were they caused by rains triggered by human hands? Has this artificial paradise been overtaken by his desire to play God?

It turned out that the rumor was false and that man had nothing to do with it, even if the Gulf countries are fond of technologies that allow them to influence the . The United Arab Emirates are indeed big users of what is called cloud seeding. For hundreds of hours each year, planes crisscross the sky to disperse silver particles that turn moisture in clouds into raindrops [lire encadré],

>> Read about it: Extratropical depression responsible for record rains in Dubai

Sorcerer’s Apprentices in the Sky

This controversy has relaunched a debate which is gaining momentum with climate change: can we play sorcerer’s apprentice in the sky to mitigate its effects? In several places around the world, these attempts are beginning to take on considerable proportions and are raising questions.

In Pakistan, artificial rains are triggered to combat pollution. Thus, in Lahore, one of the most polluted cities in the world, the drops clear the sky of dense smog which poisons the population.

>> More details in our article: Pakistani megacity of Lahore uses artificial rain to combat smog

In China, in 2008, the regime congratulated itself on having avoided precipitation throughout the Beijing Games. And the country now claims to have succeeded in increasing rainfall by 15% in arid zones. A program of unprecedented scale is in development: by 2025, it is envisaged to be able to control the weather over large areas such as India.

It also risks creating enormous diplomatic problems. If China spreads sulfur, it disrupts the monsoon in India

Dominique Bourg, philosopher and honorary professor at the University of Lausanne

Used on a large scale, these methods are worrying because of the deviations they could cause. “Repairing modifications by adding others to the first, that is not repairing! It is pretending to counter damage with another, which we do not know,” estimated the philosopher and honorary professor of the University of Lausanne Dominique Bourg last Sunday in the show Mise au Point.

“It also risks creating enormous diplomatic problems. If China spreads sulfur, it will disrupt the monsoon in India,” also warns this fervent opponent of artificial weather modifications.

Depriving yourself of tools: a risk there too?

If this risk is worrying, depriving yourself of tools to combat the effects of warming could be just as worrying, estimate the teams of physicist Jean-Pierre Wolf at the University of Geneva. They want to develop new methods to modify the weather and are the first to use lasers for this.

We have shown that with a laser, we can guide lightning

Jean-Pierre Wolf, physicist and professor in the Department of Applied Physics at UniGE

“We tested lots of things with lasers, with the aim of replacing chemicals. There was the control of lightning: we showed that with a laser, we can guide lightning,” explains the professor in the Department of Applied Physics. A full-scale experiment was carried out from the summit of Säntis (eastern ) in 2021. A historic photo shows the laser managing to capture lightning and conduct it to a lightning rod. And that’s not all: the same laser can also transform or even create clouds.

Deflection of lightning with a laser at Säntis.
Deflection of lightning with a laser at Säntis.

tools “won’t be enough”

For Jean-Pierre Wolf, extreme weather events will increase and current tools will not be enough to deal with them. “We know that even if we take measures today, we will have a period where we will exceed two degrees [de réchauffement, ndlr], because the lifespan of CO2 is very long. We risk this ‘overshoot’. This means that we can reach points of no return,” warns the physicist.

“Even if we then return to a normal situation, we may need additional measures during this transitional period, in a well-defined period, so as not to exceed certain temperatures.” He therefore calls for developing this research, but within a controlled framework.

Change the climate of the entire planet

Others want to go much further and no longer modify the weather, but the climate of the entire planet, like the Nobel Prize winner in chemistry Paul Crutzen, known in particular for having discovered why there are holes in the layer of ‘ozone. In the 2000s, he proposed depositing sulfur particles in the stratosphere so that they would reflect solar radiation, which would cool the Earth.

His idea is to somehow imitate the effects of major volcanic eruptions, like in 1991, when the Pinatubo volcano spewed an immense cloud of sulfur covering the globe. The Earth had lost 1.5 degrees over a year.

>> Read about it: Does volcanic activity really lower Earth’s temperature?

Attempting to reproduce such effects is part of what is called geoengineering. Its effects are particularly frightening, because it is difficult to predict the consequences. “If you have artificially reduced a little the quantity of solar energy reaching the ground, then you stop in a few weeks, there is massive and violent warming. We are creating a sword of Damocles,” fears Dominique Bourg.

Avoid future risks

In Bern, the issue is taken very seriously. Swiss Ambassador for the Environment Felix Wertli is following these debates closely. He even brought this issue to the United Nations. According to him, if there is “no immediate risk”, things must be put in place in advance to avoid future risks.

It is important to communicate that these technologies are not an alternative to reducing emissions

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Felix Wertli, Swiss ambassador for the environment

On a global level, it is difficult to obtain an agreement today. Some countries want to accelerate research, while others are pushing to create a moratorium now so that these technologies are never used on a large scale.

“It is important to communicate that these technologies are not an alternative to reducing emissions, on the one hand because there are risks and uncertainties linked to these technologies, and on the other because they do not are just a way to combat the symptoms of climate change,” insists Felix Wertli.

>> Read also: Changing clouds to make rain wouldn’t solve global drought

Should we experiment to find out our options, or avoid opening a potentially devastating can of worms? The political debate has only just begun.

TV topic: Céline Brichet

Web adaptation: Vincent Cherpillod

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