It's actually very easy to come up with a plan. We know exactly what activities and industries contribute the most in generating pollution and greenhouse emissions. We know the amounts per year that are produced by each of these industries. We have models-- perhaps not great ones but they're all we have for now-- that tell us estimated impact on the climate from all of the above, so that we can calculate what reductions are necessary and in what time frame.
We have all of those things, which is more than enough to come up with a fact-based plan, today. It would still depend on the accuracy of the models, but over time I believe the models will improve, so the outputs will improve, and we could course correct as better models and better data become available.
The problem is, when you actually DO the above-- when you calculate the actual costs of implementing the changes, and understand the actors that would need to engage heavily that have absolutely no desire to engage-- that's when you realize just how unrealistic it all is. We can make all the laws we want in the US but we can't force other nations to follow suit and, if they don't, then the actions we take won't make enough of a difference, but will absolutely cripple us economically vis a vis our global counterparts and competitors who'd be happy to watch us suffer.
