Can We Cool the Planet?

As global temperatures continue to rise, scientists are wondering if we need solutions that go beyond reducing emissions. From sucking carbon straight out of the air, to geoengineering our atmosphere to physically block out sunlight, to planting more than a trillion trees, the options may seem futuristic or tough to implement. But as time runs out on conventional solutions to climate change, scientists are asking the hard questions: Can new, sometimes controversial, solutions really work? And at what cost?