If the world is to avoid "severe, widespread, and irreversible [climate] impacts," carbon emissions must decrease quickly—and achieving such cuts, according to the Intergovernmental Panel on Climate Change, depends in part on the availability of "key technologies." But arguments abound against faith in technological solutions to the climate problem. Electricity grids may be ill equipped to accommodate renewable energy produced on a massive scale. Many technological innovations touted in the past have failed to achieve practical success. Even successful technologies will do little good if they mature too late to help avert climate disaster. Below, experts from India, the United States, and Bangladesh address the following questions: To what extent can the world depend on technological innovation to address climate change? And what promising technologies—in generating, storing, and saving energy, and in storing greenhouse gases or removing them from the atmosphere—show most potential to help the world come to terms with global warming?