Can we make rain

Weather manipulation: what is already possible today?

Drought, heavy rain, frost: the weather has often made the difference between life and death in human history. The desire to be able to control the weather in a targeted manner is obvious. In fact, some approaches are already being pursued. But the consequences of massive weather manipulation are still not foreseeable today.

You can find more knowledge topics here

Prevent hail and thus crop failures; create a clear view by dissolving fog fields; ensure heavy snowfall in ski areas: There are many situations in which people would like to be able to influence the weather.

And indeed: locally it is common practice in some areas to influence the weather. For centuries, for example, winemakers have been producing smoke to protect their vines from frost.

Fog fields, which obstruct the view on the runways of airports, for example, can also be resolved in different ways.

According to the meteorologist Andreas Friedrich from the German Meteorological Service, one can warm up the lower layers of the air on a small scale or introduce small particles into the fog fields, which let the fine water droplets rain down.

Another method is to set up large wind machines that mix the air and break up the fog.

Weather manipulation: sunshine for the military parade

On May 9, Moscow traditionally celebrates the victory over Nazi Germany with a large military parade. Part of the spectacle is an air show with dozens of planes and helicopters.

The Russian government does not want to leave to chance that the experience does not fall into the water for hundreds of thousands of spectators. For years she has had so-called cloud vaccinations carried out in order to let rain clouds rain down before the gates of the city and thus ensure blue skies over the parade.

Thailand's King Bhumibol Adulyadej, who died in 2016, was considered a great benefactor of his people. Among other things, he was revered by many people for generating artificial rain in agricultural areas of the country threatened by drought.

Both ideas are based on the same basic principle: In addition to moisture, precipitation requires a so-called condensation nucleus in the atmosphere. These are the smallest solid particles such as whirled up grains of dust or pollen on which water droplets form.

To create rain, clouds are sprayed from airplanes with a chemical - often silver iodide - to artificially trigger this mechanism.

Hail defense associations also want to take advantage of this principle. They try to inoculate thunderclouds in such a way that hail falls on the earth as early as possible, before the grains become very large and can thus cause more damage.

Scientists are skeptical

Even if such projects are often celebrated as a success, Friedrich considers them to be questionable. Because it is impossible to prove that they work. "A concrete situation in the atmosphere cannot be reproduced in order to check what would have happened if I had not tried to manipulate it," says the meteorologist.

When it comes to hail defense, it is also aimed at influencing thunderclouds. With the small amounts of silver iodide used on the flights, one could not achieve much, "simply because the amount of energy that is converted in such clouds is huge. What is already in a small thundercloud of energy corresponds to umpteen atom bombs", explains Friedrich.

Friedrich would advise farmers who are often customers of such hail prevention service providers to invest their money in other measures. "With hail you have little chance of preventing something. But there are insurance companies that can at least cover the financial damage," he recommends.

Consequences not foreseeable

Friedrich does not rule out that there could be more reliable technologies for influencing the weather in the near future. But you should think about whether you want to do that at all, he warns: "If you intervene massively in complex systems, you never know whether there will be surprising, unwanted feedback."

Many politicians and their advisors also seem to take the risk of possible misuse of weather manipulation seriously. The ENMOD Convention, which 77 states have signed up to now, stipulates that weather manipulation for military purposes is prohibited.

Swell:

In the Russian village of Ryrkaipij the alarm has to be raised several times a day because of polar bears. In the Arctic Ocean, the animals are increasingly coming too close to the settlements.