Marketplace did a thought-provoking story on "geo-engineering," ways to prevent the Earth from warming too much even if we can't reduce greenhouse gas emissions in time. The ideas sound like they're from science fiction novels, such as a huge space umbrella to filter the sun's rays. However, they are gaining credibility with some scientists, since the cost of addressing GHG is currently astronomical. Were we to go this route, where countries are able to "place their hand on the global thermostat," I think we would need to have a stronger international community/regulating structure to monitor the process and adjudicate among nations who want different things. Check it out.