Is geoengineering to blame?

Every Saturday we decipher climate issues with François Gemenne, professor at HEC, president of the Scientific Council of the Foundation for Nature and Man and member of the IPCC.

Return this week to the terrible floods which affected Dubai and several other Gulf countries, notably Oman, where they left 19 dead. And in particular on this controversy which is gaining momentum on social networks, according to which it is the Emirates themselves which triggered these torrential rains.

François Gemenne: it’s a theory that’s circulating quite a bit, and which points to the role of geoengineering in these floods: these torrential rains are due to a geoengineering operation that went wrong. The United Arab Emirates allegedly wanted to make artificial rain using a cloud seeding technique by plane, and the operation did not go as planned.

Cloud seeding is a fairly simple technique, actually, which involves spreading different substances, such as silver iodide or salt crystals, into clouds to trigger precipitation. It is a technique commonly used to combat droughts, for example.

And it would be this technique that would have triggered these catastrophic floods ?

The experts are very reserved. First of all, the Emirati government obviously assures that it did not carry out such an operation, and above all, we recall that the precipitation was predicted by weather models. In any case, it seems unlikely that cloud seeding alone could have triggered such rainfall. We rather look at climate change, since a warmer atmosphere is also more humid: for each additional degree of temperature, the water content of the atmosphere increases by 7%.

The controversy comes firstly from the fact that these floods are very unusual in Dubai, and also from the fact that the United Arab Emirates have regularly used this technique for around twenty years. But they are not the only ones, many countries also do it, to fight against droughts, or simply to make it rain before major events.

“China did it before the Beijing Olympic Games to reduce air pollution. In France we also do it, to combat the risk of hail on the vineyards.”

François Gemenne

on franceinfo

It’s pretty basic, it just involves triggering a chemical reaction. There are other, even more advanced techniques: we call it geoengineering, that is to say the artificial manipulation of the climate. We generally distinguish two types of techniques: those which aim to capture the carbon dioxide which is contained in the atmosphere, and those which aim to modify solar radiation, that is to say to reduce the quantity of solar radiation absorbed by the Earth.

All projects are obviously not at the same stage of development, and do not present the same risks.

There are relatively harmless projects: painting the roofs of buildings white so that they reflect more of the sun’s rays, for example, or increasing the carbon content of the soil using organic charcoal or biochar. But there are others which seem straight out of a James Bond film, and which are obviously very controversial: artificially fertilizing the oceans, injecting aerosols into the stratosphere, like sulfur particles, or even outright installing mirrors in space.

At the moment there is no regulatory framework, and therefore that means that it is authorized. The only embryo that exists is an ongoing reflection within the Commission on climate overshoot, a high-level commission set up within the Paris Forum for Peace and chaired by Pascal Lamy, the former director of the WTO. But for now, literally anyone can use it, including private individuals.

This obviously raises very serious questions: about the maturity of the technologies and the control of their side effects, and then also of course questions of security. A recent note from the Climate and Defense Observatory highlighted the risk that these technologies could be used for hostile purposes, or give rise to disagreements over their deployment methods. There is also the risk that these techniques will be used as an excuse not to reduce our emissions.

“There is obviously a fundamental ethical question: do we have the right to artificially manipulate the climate?”

François Gemenne

on franceinfo

Some will say that we improvise as demiurges, and that this is an insurmountable red line. Others, on the contrary, will say that climate change itself is already an artificial manipulation of the climate, and that geoengineering is a lesser evil. To think about these questions, there is a book that I recommend, it’s a story about the Smurfs: The Rain Smurfpublished in 1969. I won’t tell you the story, but it’s all there, you’ll see.