Albeit in a limited way, using the climate as a weapon of war is possible. Techniques such as cloud seeding, created in the 1950s to cause rain, have even been used for military purposes. The best-known example is Operation Popeye: between 1967 and 1972, during the Vietnam War, the United States seeded clouds to prolong the monsoons and hinder the enemy. It is also due to episodes like this that meteorological warfare is prohibited by an international convention in force since 1976.
Climate modification techniques
In recent times technological progress has allowed man to truly “regulate” the climate but only to a limited extent, for example by making it possible to cause rain. It is a goal that people once tried to achieve with traditional rites such as rain dances, widespread in many agricultural cultures. Today, however, the technique of cloud seeding, or cloud seedingdeveloped since the 1950s, which consists of spraying particles of substances such as silver or lead iodide into the clouds to encourage the formation of precipitation.
In some cases, experiments have also been carried out to obtain the opposite effect, i.e. to prevent it from raining. According to journalistic rumours, such a plan had been studied by the Chinese authorities during the 2008 Beijing Olympics. However, man is not able to completely control the climate and, in particular, is not able to avoid dangerous phenomena, such as hurricanes, nor to modify temperatures at will.
An example of weather warfare: Operation Popeye in Vietnam
During the Cold War, both the United States and the Soviet Union studied the possibility of modifying the climate for military purposes. In fact, weather conditions significantly influence the progress of conflicts, for example by limiting the mobility of men and vehicles. The only country that actually used climate as a weapon, as far as is publicly known, was the United States during the Vietnam War. From 1967 to 1972 the US military implemented a cloud seeding program, called Operation Popeye, aimed at extending the monsoon season. The aim was to create mud and thus damage the mobility of the Vietnamese on the dirt tracks, in particular on the Ho Chi Minh trail, i.e. the network of roads that connected North Vietnam to South Vietnam. The operation was conducted by 54th Weather Reconnaissance Squadron of the Air Force with the slogan “make mud, don’t make war” and allowed the rainy season to be extended by 30-45 days a year.
Popeye, obviously, remained a secret operation until the early 1970s, also because the American administration was aware of the objections that would be raised by the international community and scientists. In 1971 the press published some rumors about the Operation and in 1972 they were able to make more detailed information available to the public. On July 5, 1972, two days after the revelations, US authorities decided to discontinue Popeye.
In the five years during which it was conducted, the operation, although prolonging the rains, had had less significant effects than hoped for, having failed to significantly limit the fighting capacity of the Vietnamese.
What international law says
Weather warfare today is prohibited by an international convention, the Convention on the Prohibition of the Use of Environmental Modification Techniques for Military and Any Other Hostile Purposes, which came into force in 1976 and was signed by numerous countries, including the United States and other major world powers. The convention prohibits not only weather warfare, but all operations aimed at modifying the natural environment for military purposes. You can read in the first two articles:
- Each State party to this Convention undertakes not to use for military purposes or any other hostile purpose, environmental modification techniques that have widespread, long-lasting or serious effects, as means that cause destruction, damage or prejudice to any other State party. (…)
- The expression “environmental modification techniques” indicates any technique whose aim is to modify – thanks to a deliberate manipulation of natural processes – the dynamics, composition or structure of the Earth including its biotic complexes, the lithosphere, the hydrosphere and the atmosphere or outer space.
The convention was signed because public opinion and international institutions were worried about the environmental effects of conflicts, considering the fact that some states deliberately damaged ecosystems and vegetation. In particular, during the Vietnam War the United States had used large quantities of chemical defoliants (the infamous “Agent Orange”) to cause deforestation. Since the entry into force of the Convention, no army – according to what has been publicly revealed – has used weather warfare techniques again.
Conspiracy theories and global warming
Weather warfare and voluntary climate modification are at the center of some conspiracy theories, according to which alleged “strong powers” are modifying weather conditions, with so-called chemtrails or other systems, to harm humanity or for other nefarious purposes. These are, of course, completely unfounded theories, which not only have no scientific basis, but are also contrary to common sense. There is, however, a real danger linked to climate change: global warming, caused, albeit involuntarily, by human activities, as is now recognized by the entire scientific community.
