A technique known as a stratospheric aerosol injection (SAI) could reduce the global warming rate by half, according to research conducted by scientists at Harvard and Yale universities. His idea would involve spraying large amounts of sulfate particles in the lower stratosphere of Earth at altitudes of up to 20 kilometers.
Scientists say they could spray sulphates using balloons or airplanes designed to reach high altitudes, or large naval guns. However, they made it clear that the technique is, so far, purely hypothetical. There is no adequate technology or aircraft to conduct this experiment, but the team says that the system can be created within 15 years.
The cost of launching the UPS system is estimated at $ 3.5 billion, with operating costs of $ 2.25 billion per year.
The report admits that it is a hypothetical deployment, but that its creation is possible.
We do not make judgments about UPS suitability. We have simply shown that a hypothetical implementation program from the age of 15, although highly uncertain and ambitious, would indeed be technically feasible from the engineering point of view. It would also be very cheap.
The team recognizes that there would be an extreme risk with the system, since it would be necessary to coordinate between several countries in both hemispheres. In addition, they say that UPS techniques can endanger agriculture, cause droughts, or cause extreme weather conditions.
Dr. Gergot Wagner, of the Harvard School of Engineering and co-author of the study, said:
Given the potential benefits of halving the projected increases in radiative forcing of a specific date, these numbers invoke the incredible economy of solar geoengineering. Dozens of countries could finance this program, and the technology required is not particularly exotic.
The proposals also do not address the issue of rising greenhouse gas emissions, which are a major cause of global warming.
The voices against
Philippe Thalmann of the Ecole Polytechnique Fédérale de Lausanne, a specialist in climate change economics, said the system would be too expensive and much riskier in the long run.
David Archer, from the Department of Geophysical Sciences at the University of Chicago, said:
The problem with the engineering climate is that it is only a temporary band-aid covering a problem that will essentially persist forever. It will be tempting to continue putting off cleaning up our energy system, but we would be leaving the planet in a form of life support. If a future generation did not pay their climate bill, they would receive all our heating at one go.
The project was not approved by any government or authority, and additional studies would be required to verify its validity.
The results of the research were published in the scientific journal Environmental Research Letters.