We often wonder whether the government is better suited to solving many of our problems, or whether the market should take the lead.
The current issue of The Atlantic Monthly has an article concerning the efforts of Bill Clinton's foundation which addresses this issue. The article shows how governments can work with markets for the benefit of large numbers of people and the planet by guaranteeing demand for a particular product or service. By doing this in the long-term, the production of beneficial goods and services can achieve the economies of scale that will make them practical to use within a few years, instead of decades from now.
The Clinton Foundation used this powerful idea to cut prices for AIDS drugs in Africa and the Caribbean for hundreds of thousands of people. In Clinton's words, "All we did was take something that people would naturally do in a purely business market and apply it to the public-goods market."
I'm not sure if Clinton is referring to the technical definition of "public goods" here, which refers to a good whose consumption does not reduce any other's consumption of that good, and a good that all have access to, such as information or air.
The Earth's climate is most certainly a public good, and its radical warming would most certainly be a public bad. So the Clinton Foundation worked with a new group of cities, the C40, to create large-scale demand. If big cities could come together to provide a market to jumpstart new, energy-savings technologies, it would give quite a boost to efforts to mitigate global warming. As the author of The Atlantic article points out, cities have quite a source of demand at their disposal: