STRATOSPHERIC AEROSOL INJECTION (SAI)

Nov. 25, 2018

In a new paper published in Environmental Research Letters researchers discuss the potential to use a new solar geoengineering technique known as Stratospheric Aerosol Injection (SAI) to help cool the Earth over a long period of time.

About:

Objective: Stratospheric Aerosol Injection (SAI) is an unproven and hypothetical geo-engineering technique that could limit rising temperatures that are causing climate change.
Working:
- It would involve the use of huge hoses, cannons or specially designed aircraft to spray large quantities of sulphate particles into the upper layer of the atmosphere to act as a reflective barrier against sunlight.
- The research assumes a special aircraft can be designed to fly at an altitude of about 20 km and carry a load of 25 tonnes.
Timeline: These scientists have developed a design that could be ready to be deployed in 15 years.
Cost: SAI program could be remarkably inexpensive. Total costs to launch a hypothetical SAI effort 15 years from now would be $3.5 billion, and the average annual operating costs would be about $2.25 billion a year over 15 years.
Concerns:
- SAI could cause droughts or extreme weather in other parts of the world, harm crop yields as well as potential public health and governance issues.
- It also does not address the issue of rising carbon dioxide emissions, the main greenhouse gas blamed for global warming.