STRATOSPHERIC AEROSOL INJECTION (SAI)
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.
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.
