There is ABSOLUTELY NOTHING that humans can do to impact the climate, or to slow the inevitable warming of the planet, whether it is cyclical or not. "We" can only devise engineering solutions to the problems that arise, as they become real problems.
The portion of the earth's "greenhouse gases" that are the product of humans' discretionary emissions of same is so small as to be a joke in the overall scheme of things. To wit, what would Senator Sanders do about the burning of carbon fuel in oceangoing vessels (essential to the global economy), airplanes, construction equipment, over-the-road trucking, agricultural machinery, and essential human transportation (leaving out discretionary travel, which is manageable)? How would they propose producing the electricity to power the Electric Vehicles that they demand we buy? Adjusting our thermostats, Summer and Winter, is also a joke in the overall scheme of things.
What is the percentage of the earth's population that gives a shit about climate change, and has the resources to even think about curtailing greenhouse gas emissions? It is about 25%, with 75% struggling to facilitate burning MORE carbon, so they can have things like electricity, heat in Winter, and cooling in summer, transportation, modern agriculture, and so on. Do you think the peasants in India, China, and Africa who are cooking their food on dung fires give a damn about their carbon footprint? I personally do not. And these unfortunates comprise more than half of the world's population.
This is nothing but a power play by the world's Leftists to gain control of the world's production and transportation resources, and to curtail economic activity that they simply do not like.
If such people were serious, they would be very much "on the bandwagon" to increase the global scope of nuclear power - the best feasible way to reduce the production of greenhouse gases. But they oppose nuclear power because apparently, they got an overdose of Godzilla movies when they were children and have no concept of the actual dangers of nuclear radiation.
It is difficult to say whether Sanders is stupid or corrupt; someone who has been successful into his 80's without ever actually having had a job is hardly a person to be taken seriously about serious issues.
A vote for any Democrat is a vote for Sanders and people like him. If Trump is the only alternative, then vote for Trump.