If governments and businesses are unable to meet current targets to reduce planet-warming emissions, the world will need to accelerate research into fantastical, and as-of-now untested, technologies to soften the blow of climate change.
Limiting global temperature rise to no more than 1.5˚C, or 2.7˚F, means reducing greenhouse gas emissions in the near term, according to the United Nations. But humanity had better have some aces up its sleeve in the event it is unable to do that in time. If climate scenarios devolve into truly apocalyptic realities, the world might have to resort to stopgap solutions that artificially slow the pace of warming by adjusting how much the sun heats the earth.
