Scientists are supportive of the stratospheric solar radiation barrier to curb global warming

LONDON (Reuters) – Spraying chemicals tarnishing the sun over the Earth to slow global warming could be "remarkably cheap", according to a study by US scientists, costing about $ 2.25 billions of dollars a year over a period of 15 years.

Some researchers have stated that the technique of geoengineering known as aerosol injection into the stratosphere (SAI) could limit the rise in temperatures at the origin of climate change.

This is not yet proven or hypothetical, it would be necessary to use huge pipes, guns or planes specially designed to spray large amounts of sulfate particles in the upper layer of the atmosphere and thus act as a reflective barrier against sunlight .

The total costs to launch a hypothetical effort of SAIs in 15 years would rise to $ 3.5 billion, said Harvard University scientists in a report published in the journal Environmental Research Letters, adding that average annual operating costs would be about $ 2.25 billion a year over 15 years.

The research assumes that, given the costs and feasibility, another aircraft can be designed to fly at an altitude of about 20 km and carry a 25-tonne load.

After communicating directly with several aerospace and engine companies, the scientists said they have developed a concept that can be adapted and ready to be deployed in 15 years, with the aim of halving the rate of change in temperature.

The scientists pointed out that it was only a hypothetical scenario.

"We do not make any judgment about the opportunity of the SAI. We simply show that a hypothetical deployment program starting in 15 years, while being very uncertain and ambitious, would in fact be technically feasible from the point of view of engineering. It would also be remarkably cheap, "the report said.

There are risks for these unproven potential technologies. Scientists have said that the ISC could have negative consequences, such as droughts or extreme weather conditions around the world, adversely affect crop yields, as well as potential public health and governance issues. .

Nor does it address the problem of increasing emissions of carbon dioxide, the main greenhouse gas attributed to global warming.

Commenting on the study, Phil Williamson of the University of East Anglia said: "Such scenarios are fraught with pitfalls – and an international agreement to move forward with a such action would seem almost impossible to obtain. "