You seem to be conflating two sides of the issue. There's pretty strong understanding of what is happening (global warming with a human-caused element), and conceptually what needs to happen (reduce emission of greenhouse gasses to reduce the human element). How that gets done is not a single, sweeping solution. It's probably several thousand solutions - some large and some small. We know enough to get started, while we figure out the rest. Simple things like restricting emissions goes a long way - and some of that simply requires government, because individual consumers drive businesses to do things that are counter to our collective needs.
For that latter point, fuel economy is an easy example. We can (and do) make cars that get more than 40MPG. Many people prefer to buy vehicles that get 20 or less. For some of those people, that's actually a proper decision (can't haul construction goods in a hatchback). But I know several couples with a single child or no children who choose enormous cars (some of which are just plain more fun to own). Why? It's a cycle. Consumers like SUV's, so manufacturers make them. They've made them, so they market them. They want to sell more, so they market them as family vehicles, sport vehicles, etc. Now more consumers want them. Now, increase CAFE standards (for those outside the US, that's regulated requirements that include fuel economy requirements for new vehicles), and manufacturers make more fuel-efficient cars. Since they've made more of them, they want to sell them, so they market them. Turns out, what's marketed well, sells better, which can help contribute to the overall solution.
Nobody I'm aware of is asking for a single, sweeping reform that fixes everything at once. What we want is progress in the right direction, rather than regression toward the practices that led to the current situation.
