Scientists propose spraying of sulphate particles to reduce global warming rates

by Elton Gomes

Scientists are proposing a method, which is yet to be proved, to tackle climate change: spraying sun-dimming chemicals into the Earth’s atmosphere.

The research led by scientists at Harvard and Yale universities has been published in the journal Environmental Research Letters. The research suggests using a technique known as stratospheric aerosol injection (SAI), which could potentially reduce the rate of global warming in half.

Spraying sun-dimming chemicals high above the Earth to slow global warming could be “remarkably inexpensive”. The method could cost about $2.25 billion a year over a 15-year period, the scientists said.

The total costs involved in launching a hypothetical SAI effort 15 years from now would be $3.5 billion, scientists from Harvard University said.

What is the technique?

The technique remains unproven and would involve the use of huge hoses, cannons, or specially designed planes to spray large quantities of sulphate particles into the upper layer of the atmosphere. The particles would act as a reflective barrier against sunlight.

A new plane will be needed

Scientists have said that a specially-designed plane will be required to spray sulphate particles, because such missions would be conducted at nearly double the cruising altitude of commercial airplanes. The team has come up with its own aircraft called the SAI Lofter (SAIL).

The study’s co-author Wake Smith is a lecturer at Yale College. Smith has also been CEO of Pemco World Air Services (a leading aircraft modification company), COO of Atlas Air Worldwide Holdings (a global cargo airline), and President of the flight training division of Boeing.

He said in statement: “It would indeed take an entirely new plane design to do SAI under reasonable albeit entirely hypothetical parameters. No existing aircraft has the combination of altitude and payload capabilities required.”

Smith added SAIL will be need roughly double the wing area of an equivalently sized airliner, and double the thrust. It will have four engines instead of two. He further said, “At the same time, its fuselage would be stubby and narrow, sized to accommodate a heavy but dense mass of molten sulphur rather than the large volume of space and air required for passengers.”

What are the risks?

Scientists, however, have also said that SAI could have its risks. For instance, SAI techniques require coordination between multiple countries in both hemispheres. Additionally, such techniques could affect crop yields and lead to droughts or cause extreme weather.

A previous report on the dangers of using SAI techniques indicated that spraying aerosol in the northern hemisphere would lead to fewer cyclones in the North Atlantic, but it would create drought-like conditions in sub-Saharan Africa and parts of India.

So it would be “good for the southeast US, the Caribbean, and Mexico in terms of dissipating storms,” lead author Anthony Jones was quoted as saying by Verge. But it would be disastrous for other parts of the world.

Stratospheric aerosol injection perhaps is not an ideal remedy to climate change, but Harvard scientists seem to be moving forward with the idea. Though SAI is an interesting technique, it’s equally important to also think about the potential risks and uneven consequences.

Elton Gomes is a staff writer at Qrius




EnvironmentGlobal WarmingHarvardPlanet EarthScienceYale