I've heard a few people argue that growth is the problem, but they're fringe economic thinkers. Most green types I know want to see dirty ofssil fuels displaced by a cleaner more effective solution that will support continued growth, The more serious ones see nuclear as part of the toolset for that.

Your argument about the deficiencies of models involves a number of unsupportable assumptions, particularly the assertion that because the climate is so big and complex that it's impossible to validate any part of our model. On the contrary, we're able to do very rigorous measurements in multiple dimensions on things like glaciers and polar ice density. I don't think you'd take me seriously if you said cosmology was a fundamentally doomed enterprise because the universe is so big. If we are willing to invest in space science to further the aim of travel and seeking life on other planets in the solar system (which aims the science committee does favor), then it's not unreasonable to think we can do at least a good a job of studying our own planet as exploring travel to others (an aim I also support).