text:  He says cheap solar power has been the fastest growing electricity source for 17 straight years. And renewables aren't the only ways countries are trying to cut emissions, says Melissa Lott with Columbia University's Climate School. We've seen some countries leaning into nuclear power, others exploring carbon capture. Altogether, that means the power sector is moving in the right direction. But she says emissions from this sector can change unexpectedly thanks to things like volatile weather.