Stratospheric aerosol injection (SAI)

Stratospheric aerosol injection (SAI) is a geoengineering technique that involves injecting aerosols (tiny reflective particles), such as sulphur dioxide, into the stratosphere to reflect sunlight away from Earth, thereby cooling the planet. The idea is modeled after volcanic eruptions, which naturally release aerosols and have a temporary cooling effect on global temperatures.

A recent study published in Earth’s Future explores a more cost-effective and potentially feasible approach to SAI. The researchers propose injecting 12 million tonnes of sulphur dioxide annually at 13 km altitude during the spring and summer seasons in each hemisphere. According to the findings, this could lower global temperatures by approximately 0.6°C.

Despite its potential, SAI remains controversial due to ethical, environmental, and governance concerns, and because it does not address the root cause of climate change — greenhouse gas emissions.

(Source: TH)