There are many technologies used for reducing CO2 emissions—efficiency improvements, wind power, and what have you—but on CO2 storage I want to add two things. One is that it is in principle—and there are some facilities moving towards this in the world—possible to capture CO2 from a facility that uses biomass, say from a facility that's burning forest waste. Then you've essentially made negative emissions, because in the net, you're taking carbon out of the atmosphere forestry system and putting it deep underground.
That will be done in Berlin quite soon, and I forget the exact start date. There's an IGCC power plant facility in the Netherlands that's now burning a substantial fraction—more than 30% of its fuel is biomass—and they will likely do capture. That will be a negative emissions facility, essentially—directly, not in an economic sense, but directly, physically—offsetting other emissions by being negative.
That's another opportunity in general. It's a higher-cost opportunity, partly because most of the forest resources are smaller, but it's something to think about for the future.