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Scientists have up with a revolutionary new idea to planet Earth from global warming. Geo-engineers from Harvard University that spraying "sun-dimming" chemicals into the stratosphere high above the Earth could down global warming. They also say their technique would "remarkably inexpensive," costing in the region of $2.25 billion a year over a 15-year period. The technique is as stratospheric aerosol injection (SAI). It is still in its infancy and is yet to be . It would the use of gigantic hoses or high-powered chemical cannons to chemicals into the stratosphere to as a reflective barrier against sunlight and harmful UV rays.

The scientists have that their idea is currently still in the planning stages. They said: "We no judgment about the desirability of SAI. We simply that a hypothetical deployment program commencing 15 years hence, while both highly uncertain and ambitious, would indeed technically possible from an engineering perspective." Not all scientists the idea is a good one. Some it is somewhat pie in the sky. They say it would a fleet of 100 specially-designed planes to make 4,000 missions a year, most of the globe's airspace. This would permission from over 100 governments. There also concerns it could increase droughts and extreme weather.

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