Hard question. I don't think political parties have the gumption to do what is needed as it will piss everyone off (particularly the climate change deniers such as found on this thread) and they will subsequently lose power. I'm not sure what is needed but I have some thoughts on what might be a good starting point. And while I agree we really need to get the biggest polluters to change, I doubt we will have much luck with that if we're going to just continue as we are.
Severe limits on flights, particularly private jets... maybe some sort of annual limit per person, which could be traded (no, I know this would probably never work, but I'm not an expert!)
Significant investment in local public transport systems so that those living in cities, towns and well connected villages can rely more on buses and trains and less on cars.
A total rethink on incentives and taxes for cars. Right now i think the incentives are there to scrap small, efficient petrol or diesel cars and replace them with large, heavy electric or hybrid cars (which need a lot of energy and resource to construct). Should be moving more to small efficient cars, not electric SUVs, and aiming to maximize the life of existing vehicles.
Stop licensing for new oil and gas exploration. Increase investment in green energy.
I actually think the whole economic model is wrong and always has been, we need to move away from consumer culture... but I'll stop with my pie in the sky before getting into that!
Like I said, I'm no expert, no idea if these ideas would even be helpful in reality.