SCIENTISTS CONSIDER THE POSSIBILITY OF DIMMING SUN TO SLOW GLOBAL WARMING

New study has found that an atmospheric spraying program would be effective and remarkably inexpensive.

It is possible to slow down and even stop global warming by injecting aerosols into the atmosphere. The idea has been around for years, but it was not until recently that researchers have examined the cost of a large-scale project that could deliver sulphates into the lower stratosphere at altitudes around 20 kilometers, known as stratospheric aerosol injection (SAI). The study found that such kind of ‘solar geoengineering’ project carried out by high-altitude aircraft is quite realistic and inexpensive and could cut the rate of global warming in half.

“Solar geoengineering is often described as ‘fast, cheap, and imperfect.’ While we don't make any judgement about the desirability of SAI, we do show that a hypothetical deployment program starting 15 years from now, while both highly uncertain and ambitious, would be technically possible strictly from an engineering perspective. It would also be remarkably inexpensive, at an average of around $2 to 2.5 billion per year over the first 15 years.” Dr. Gernot Wagner, from Harvard University's John A. Paulson School of Engineering and Applied Sciences said in a statement.

As the planet continues to heat up due to the excessive release of greenhouse gases into the atmosphere, researchers are looking for different ways to counter their effect. One approach is dimming sun which relies on spraying sulfate aerosols into the stratosphere. Researchers know that large amounts of aerosols are extremely efficient in cooling down the climate and their impact has been observed after large volcanic eruptions.

In order to spray aerosols in stratosphere, researchers are planning to use fleet of planes. The fleet would comprise of eight planes in the first year, rising to a fleet of just under 100 within 15 years. Researchers estimate the total development cost for the airframe to be $2 billion and $350 million to modify existing engines.

“Given the potential benefits of halving average projected increases in radiative forcing from a particular date onward, these numbers invoke the 'incredible economics' of solar geoengineering,” said Dr. Wagner. “Dozens of countries could fund such a program, and the required technology is not particularly exotic."