Global warming is happening already, and there is nothing we can do to stop it. Trying to change the habits of the whole world is just a huge waste of time, with zero chance of success.
What we should do instead is research into the direct and indirect effects of global warming, and into ways to survive it.
There are things governments can do directly to reverse global warming, but those things have the potential to become even bigger catastrophes if they're done wrong. Things such as seeding the atmosphere with chemicals that reflect sunlight back into space.
If such an experiment goes wrong, it could change the climate of the whole planet into perpetual winter, with no agriculture, and most of the human race wiped out by starvation within a few years. We could eat fish, but the fish would become extinct soon too.
Once the world starts getting colder, the whiteness of the snow reflects sunlight back into space, causing the cooling to accelerate.
