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

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

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