July 20. American scientists from Harvard University are planning for the coming year to experiment spraying sulphate aerosols that block sunlight from entering the earth's surface, the newspaper Guardian.
Spraying sulphate aerosols (fine particulate matter) in the lower stratosphere — one of the most popular global geoengineering projects to combat global warming.
It is assumed that this will create a screen reflecting solar radiation back into space, and slow the rate of warming. The idea of the project came after the eruption of Mount Pinatubo in the Philippines in 1991, when the stratosphere hit 20 million tons of sulfur dioxide. Then, from 1991 to 1993, the average global temperature has decreased by about 0.5 degrees Celsius.
The experiment will be conducted in the state of New Mexico (USA). It is planned to spray a few hundred kilograms of sulphate to evaluate their interaction with ozone and eliminate the possibility of chemical reactions and other "side effects". In addition, researchers need to determine the optimal size of the particles. Experts believe that the risk of this experiment is minimal, and the benefit is obvious: even on a small scale will be possible to assess the effectiveness of this technique, the report said.
Sulfate aerosols will disperse in the lower stratosphere — at an altitude of about 24 kilometers — with automatic balloons.
However, scientists from the California Institute of Technology (USA) found that spraying aerosols may cause "side effects", one of which — much lighter color of the sky in the daytime. It is estimated that 2% shielding sunlight can make the sky five times lighter and brighter. Sky will retain a blue hue, but in all the land will look "whitish" and hazy, as over a major city on a hot afternoon.
Scientists note that there are a number of effects that can occur when spraying aerosol. For example, after the sun in the sky will be seen a long flashes, similar to the aurora borealis.
Another effect that scientists foresee — the uncontrolled growth of all vegetation on the planet. New lighting conditions with the brightness of a lamp as the light of day, will inevitably cause the acceleration of photosynthesis, in which will be withdrawn from the atmosphere much more CO2 is required for this biochemical reaction.