Credit: Nick Reddyhoff

The hot investments these days involve renewable-energy technologies that promise to generate electricity completely free of emissions, along with biofuels that promise to end global demand for coal and petroleum. Unfortunately, these technologies are not economically, technically, or logistically ready to be adopted on a large scale. Renewable energy will ultimately be a critical element of a more sustainable world. But if we have any hope of winning the battle against climate change, we must also focus on solutions that can have a bigger impact faster.

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