Stratospheric aerosol injection
Also called: Solar geoengineering · Topic: Atmosphere: Composition, Structure and Elements of Weather · NCERT: Beyond NCERT
Meaning
Stratospheric aerosol injection is a geoengineering idea, which means a plan to change the climate on purpose. Reflective particles, such as sulphate, would be sprayed into the stratosphere to bounce some sunlight back to space and cool the Earth. It copies what large volcanic eruptions do naturally. It is untested at scale. It could slow the recovery of the ozone layer and upset monsoon rain. If it were stopped suddenly, it could cause rapid "termination shock" warming.
Example
When Mount Pinatubo in the Philippines erupted in 1991, it pushed sulphate particles into the stratosphere. They cooled the Earth's surface for a year or two. Stratospheric aerosol injection would try to copy this cooling on purpose.
Don't confuse with
- Cloud seeding: this sprays particles into clouds in the lower atmosphere to make them rain in one area. It does not try to cool the whole planet.