Complex sentence: The Sunshade would block out only 2% of the sunlight, reflecting it off into space, but this would be enough to halt global warming, giving us ample time to cut our emissions back on earth.
Split into simpler sentences: The Sunshade would block out only 2% of the sunlight, reflecting it off into space. But this would be enough to holt global warming, giving us ample time to cut our emmisions back on earth.