Mexico, artificial rain against drought: cloud seeding is being tested

It hasn’t rained in Mexico for days. Drought is gripping the country, consequently causing a series of serious hardships: from lack of water, to damage to agriculture, up to the loss of crops with a serious increase in food prices. To try to solve the problem – at least temporarily – the Mexican government has chosen to test a rather controversial new technology, cloud seeding. It is a system of “artificial seeding of the clouds”, which provides for the spraying of silver iodide particles directly into the clouds by means of aircraft: a technique which, by increasing the level of humidity, stimulates rainfall.

How cloud seeding works

It is not a recent technology: as CNN explains, the cloud seeding system was discovered in the 1940s and has been used in about 50 countries, including China and the United States: in particular Utah, North Dakota and Wyoming (where it is even been used to create snow). Cloud seeding, which can be done both from the ground and in the air via aircraft, injects tiny particles of silver iodide into clouds, generating large amounts of rain (far more than clouds would naturally be able to). The most widespread technique for spreading the substance in the skies involves the use of rockets positioned on the wings and on the belly of the planes.

Drought in Mexico

According to the National Meteorological Service, more than 40% of the territory of Mexico was affected by drought in mid-July, with severe heat waves that killed at least 249 people in the last four months. A situation destined only to get worse, as the experts point out, according to whom the consequences of climate change (from extreme heat to lack of water) will become increasingly common and intense.

On the other hand, the Mexican government is satisfied, declaring that its current cloud seeding project, which has been in place since December 2020, has had a positive impact: according to government sources, in 2021 the seeding of clouds has generated 40% more rainfall. “Our projects have all been successful,” said a spokesperson for Startup Renaissance, a rain-boosting company that has been working on the Mexican project since 2020. But many scientists remain skeptical.

The opinion of scientists

This technology has repeatedly clashed with the skepticism and perplexity of some experts, who reiterate that systems of this type cannot provide a solution to the root problem. “Cloud seeding doesn’t solve droughts,” said Julie Gondzar, Wyoming’s climate modification program manager. “You can’t interrupt a drought with cloud seeding – she explains – It’s a tool in a toolbox”. “Concrete evidence” is lacking, according to Fernando García García and Guillermo Montero Martínez, scholars at the National Autonomous University of Mexico. “The lack of a complete understanding of the physical processes of the atmosphere and the formation of clouds and precipitation – the experts explain in an article – is one of the limitations for verifying the results obtained in all types of artificial weather modification projects. The biggest drawback lies in the natural variability of rainfall.” Mexican experts also point out that “there is no evidence that cloud seeding techniques can increase rainfall over areas of economic importance, nor is there any certainty of extrazonal effects.”