Opinion Sur Joven

Cracked earth, ferocious fires, the rationing of water, the destruction of crops and the forced displacement of people. These images come to our minds when we contemplate one of the worst aspects of climate change, one that has been particularly exacerbated by global warming, drought.

The scarcity of water especially affects certain countries, for example, Australia. Not too long ago, the latter’s situation reached an extreme when a huge dust cloud, coming from the country’s interior, swept over the eastern part of the island, completely covering Sydney, affecting traffic, further eroding soil, forcing people to stay at home.

In Latin America, Ecuador, Bolivia and Paraguay acutely suffer from drought; further away, Portugal, Spain and China also have problems. All are countries where severe dry spells have recently hit. In Argentina, the worst drought in the last 70 years has generated multi-million dollar losses.

Amidst all of this, a news flash traveled around the world. In Beijing, the capital of China, which is situated in a region under siege by drought, on the first of November people awoke to a massive snowstorm, purportedly generated by government meteorological intervention. Is this myth or scientific achievement?

Urban Legend

A few days prior to the inauguration of the 2008 Olympic Games, the Chinese government bragged about having dispersed clouds, thus avoiding rain. Now, they claim to have catalyzed the copious snowstorm that fell over the Asian giant’s capital. According to the Beijing office of Meteorological Modification, 186 doses of silver iodide were seeded into clouds over an 11 hour span. Subsequently, 16 million cubic meters of snow fell.

“This method is 50 years old, but it is crazy how they silvercoat it, and also how the media has dealt with it. You can’t generate rain or snow where there isn’t any. The information is manipulated to lobby in favor of political decisions”, asserts José Bianco, a meteorologist who works for the Argentinean TN news network and also for channel 13.

After becoming familiar with the information, he established that the Chinese Meteorological Service had already acknowledged the potential for snowfall in the area. “The use of iodide rockets to achieve the desired objective seems more like a political tool, considering that it can be used to influence public opinion”, indicates Bianco, who questions why the media would propagate such news without providing more detail or analyzing its veracity.

“Nobody that I see on TV who has spoken about this meteorological information has studied anything remotely related; at most, they were agricultural engineers. They habitually make mistakes. I think that it has more to do with laziness, than a political agenda. In this case, the news about the supposed artificial snowfall was rooted in curiosity, and it was repeated, but all the same it was false information”, he complains.

Why was the Chinese artificial rain just a myth? “The making of rain is a complex process, which involves more than one ingredient. In order for it to rain the atmosphere must contain certain levels of humidity and of instability, that can trigger condensation, leading to the falling of drops”, explains Andrea Saulo in an interview with

Opinión Sur Joven

, a professor of atmospheric sciences and director of the Department of Atmospheric Sciences and Oceans at the University of Buenos Aires.

It only rains if air, hotter than its surrounding air, rises. The hotter the air, the less dense it is. Saulo exemplifies this process by means of a daily occurrence: “It is like when you turn on a stove, and the hot air becomes concentrated on the ceiling of the room”.

Upon rising, the air becomes colder, and the possibility for condensation exists. Tiny particles, called condensation nuclei, are key in this process. They facilitate the formation of the drop, which begins to grow, and eventually falls in the form of rain.

Another important detail is cloud formation. The clouds must be large enough to allow for the drops to fall as precipitation. “Within the context of a drought, to think about making rain out of nothing is absolutely impossible. Not just because you seed a cloud with a sliver iodide, will rain be made. Many different elements must be present, 99% of them are uncontrollable”, maintains Sauro.

“All rainmaking experiments are highly controversial throughout the scientific world. There is nothing written that demonstrates that the iodide was responsible for the pseudo artificial rain in China. In meteorology it is very difficult to isolate in order to conduct an experiment, primarily because you cannot isolate the atmosphere. Identical conditions cannot be recreated”, she adds.

For science, silver iodide -a chemical substance that is created in labs, that facilitates the formation of cystals through the deposition of vapor or, in other words, changes a gas to a solid- in and of itself, does not generate anything.

Just as Bianco pointed out, sodium iodide was used over 50 years ago in Argentina. In the province of Mendoza, it was implemented to protect the vineyards from hail that tends to fall in that region. Inside a cloud which contains a large quantity of crystals, silver iodide is injected to form many small crystals, avoiding precipitation in the from of stone-like hail.

Thus, despite what the Chinese have attempted to make people believe (perhaps this was a symbolic display of power), both snow and rain are derived from a series of complex processes, which come about through the confluence of many factors. And man, although he/she may want to, cannot will it into existence, no matter how much iodide is used.

Change that is not change

At a moment when global warming in recognized as being concrete and tangible, rather than a myth, certain beliefs can reach extremes, and their influence on day to day affairs, overestimated. Just as the Chinese have exaggerated, trying to sell the news that they can manipulate the weather to the world, from time to time public opinion is dominated by the belief that all environmental ruin is a product of human contamination.

“In Argentina, 70 years ago there was a similar drought, equally severe. It seems as though this is more serious because a lot of economic activity has been affected. Therefore, it is necessary to work to mitigate the impact”, affirms Sauro, reminding us that, although we may think that we are the center of the world, the Earth has its own timetables, its own cycles, and that there have always been droughts, periods of increased humidity, increased cold and increased heat.

“Humans have to learn to live with natural variation; the system varies, and humans have to learn to coexist with nature, which they don’t dominate. It has been shown that weather patterns are changing, but we haven’t paid much attention to nature’s important fluctuations. The challenge is to learn how to manage these oscillations”, she concludes.

Not only should science work towards a productive restructuring to achieve an environmentally sustainable system, but it should also work to inspire people to think about new ways of mitigating the damages resulting from natural cycles, like drought. Both phenomena run hand in hand, but until now, solutions have arrived on their own and the results are far from being ideal.