Cloud seeding: From a weapon of war to a solution proposed for Delhi’s polluted skies

Commercial upwind control, particularly unreality seeding, adjacent appeared successful cartoons. In Looney Tunes’ 1936 abbreviated film Porky the Rain-Maker, Porky faces a drought and buys ‘rain pills’ from Dr Quack, who launches them into the entity with a peashooter, causing contiguous rainfall. Similarly, successful Walt Disney’s Comics and Stories (1953), Donald Duck becomes M.R.M. (Master Rainmaker), having perfected the creation of rainmaking.

Cloud seeding is often seen arsenic a ‘silver bullet’ for upwind modification. It involves adding metallic iodide to clouds, helping signifier crystal crystals and causing h2o to crook into rainfall oregon snow. The extremity is to summation precipitation by ensuring much rainfall reaches the crushed compared to the magnitude of h2o vapour successful the clouds.

The conception of unreality seeding was discovered by Vincent Schaefer successful 1946 portion moving astatine the General Electric Research Laboratory successful Schenectady, New York. In an effort to make artificial clouds successful a acold chamber, Schaefer added adust crystal to further chill the compartment, and a unreality instantly formed astir the adust ice. The microscopic crystal crystals successful the adust crystal provided a cleanable effect for h2o vapour to condense.

Together, Schaefer and physicist Bernard Vonnegut flew successful a single-engine level to find suitable clouds. After uncovering the close conditions, Schaefer released 3 pounds of adust crystal shavings from the cockpit, and scientists connected the crushed watched arsenic snowfall fell from the seeded cloud. Later, Vonnegut discovered that metallic iodide was much effectual than adust crystal successful nucleating clouds.

Following these breakthroughs, the US Army Signal Corps signed a declaration with General Electric successful February 1947 for fog and cloud-dispersion research. It was initially called the ‘snow project’ and aboriginal renamed Project Cirrus, historiographer Kristine C Harper notes in Make It Rain: State Control of the Atmosphere successful Twentieth-Century America. “In their associated statement, the Signal Corps and General Electric announced that their probe mightiness pb to the ‘manipulation of gigantic earthy forces for the payment of mankind everywhere’,” Harper states.

Weather power successful warfare

Through Project Cirrus, America learned however upwind power could beryllium utilized successful warfare to little force morale by creating harsh weather, damaging crops to disrupt nutrient supplies, and triggering snowfall to uncover hidden positions and force enactment on proviso routes.

“For postwar America’s subject and civilian leaders consenting to exploit immoderate vantage successful the nation’s progressively adversarial narration with the Soviet Union, the anticipation of ensuring nationalist information by controlling the upwind was excessively tantalizing to walk up,” says Harper.

Cloud seeding gained planetary attraction during the Cold War arsenic governments explored upwind power for subject and cultivation purposes. By the 1960s, the method was deployed successful the Vietnam War (1955-1975) with the US Department of Defense seeding clouds to widen the monsoon play on the Ho Chi Minh Trail during Operation Popeye (1967-72). What began arsenic the experimental Project Popeye evolved into Project Compatriot, turning upwind into a weapon.

Harper notes that the method proved effectual successful Vietnam and Laos owed to the ample cumulus clouds earlier and aft the summertime monsoon. When metallic iodide-filled canisters were released into the clouds, they “blew up” into a distinctive shape. The resulting continuous rainfall slowed motortruck postulation connected the trail, successfully denying its usage arsenic a proviso route.

“The complaint volition beryllium made that we [the United States] person been the archetypal to unfastened a ‘Pandora’s box’ of chartless threats to aboriginal civilizations,” Harper records Donald Hornig, Science Adviser to US President Lyndon B Johnson, arsenic writing.

As they brainstormed however to support the imaginable nonaccomplishment of life, land, and crops caused by rainfall from unreality seeding successful North Vietnam, Walt Whitman Rostow, nationalist information advisor to President Johnson, argued, says Harper, “Our lone defence would beryllium …that rainmaking was being utilized arsenic a humane and effectual non-lethal supplement to our bombing of the North.”

The US Air Force’s 54th Weather Reconnaissance Squadron, which carried retired astir of these operations, claimed their extremity was to “make mud, not war”, Harper states.

A clime adaptation strategy

After the Vietnam War, the United Nations General Assembly adopted the 1976 ‘Convention connected the Prohibition of Military oregon Any Other Hostile Use of Environmental Modification Techniques’ treaty, which aimed to restrict upwind modification to peaceful purposes. By the 1980s, unreality seeding fell retired of favour owed to ethical and biology concerns.

Despite lingering technological uncertainties, however, unreality seeding has returned arsenic a clime adaptation strategy. Today, it is wide utilized successful arid regions to boost precipitation artificially and is besides employed to wide airdrome fog, combat wood fires, suppress hail, and adjacent divert rainfall, arsenic seen during the 2008 Beijing Olympics.