Produced by: Tarun Mishra
Scientists in the United States conducted a secret test aimed at cooling the Earth by bouncing back some of the Sun's rays into space, as reported by the New York Times.
The experiment involved the use of cloud brightening, a technique that aims to make clouds brighter to reflect a small fraction of incoming sunlight, thus lowering temperatures.
The test, conducted on April 2, was part of a project titled CAARE, where researchers from the University of Washington launched a mist of salt particles into the sky from a decommissioned aircraft carrier in San Francisco.
The idea behind the technology is to use clouds as mirrors that reflect sunlight, a concept proposed by British physicist John Latham in 1990. The aim is to create a fleet of devices that can spray seawater droplets into the air to deflect solar heat and reduce Earth's temperatures.
The technology works on the principle that a large number of small droplets reflect more sunlight than a small number of large droplets. Hence, spraying a mist of aerosol saltwater into the air could effectively bounce back sunlight.
It is crucial to get the size and number of particles right. Scientists need particles that are extremely small, about 1/700th the thickness of a human hair, and spray quadrillions of such particles every second.
Credit: NASA Earth Observatory
The technology is being explored as a potential solution to counteract global warming caused by increased CO2 emissions. However, its long-term effects and predictability remain uncertain, with concerns raised about potential changes in climate patterns over time.
Excessive use of the technology could lead to unintended consequences, such as alterations in ocean temperatures, marine biology, and rainfall patterns, with varying impacts on different regions of the world.