The modern concept of geo-engineering (or climate engineering) refers to tasks undertaken to deliberately manipulate the Earth's climate to counteract the effects of global warming. Geo-engineering is in the news right now because US researchers are studying various elements like the steam from ships, condensation trails of airplanes and volcanic eruptions to understand how changing these processes could slow global warming.
Geo-engineering is based on the principle that practices such as seeding clouds to make them brighter and more reflective, could bring down global temperatures.
One geo-engineering study showed that large ships that spew tiny particles into the sky change the characteristics of clouds, making droplets in the clouds more numerous and smaller. A cloud with more droplets is brighter and reflects more sunlight, preventing the sunlight from hitting the Earth's surface and warming it up.
Another area of study for geo-engineers is major volcanic eruptions, which spew sulphurous gases into the air and also cause cooler temperatures afterwards. Some scientists have suggested shooting sulphurous gas into the air from jets that fl y at high altitudes as a geo-engineering strategy. The gas would condense and form particles in clouds, making them more reflective.
As of now, scientists are still working on the science but these studies might prevent temperatures from soaring in the future.