Researchers in the journal Nature argued this week that one of the most effective ways to tackle global warming will be to take carbon dioxide right out of the atmosphere. CO2 is a greenhouse gas, and one of the leading causes of global warming.The scientists note several technologies already under development to coax carbon out of the atmosphere. You can read about the methods here. Basically all of them involve chemical reactions that trap CO2 or bind it to another substance. Challenges remain, though: the processes are expensive, and then there's the issue of what to do with the carbon once you've sucked it out of the atmosphere.News of these developments made me think of a recent blog post from New York Times environment reporter Andrew Revkin . Revkin posed the question: Global Warming: Pollution Problem or Technology Problem? Then he asked scientists and policy gurus to respond. Most say, of course, it's both. But it will be interesting to see where President-Elect Obama's newly named energy and environment officials focus their efforts. Will it be more about curbing pollution, more about funding technological innovation, or both?