Decoupling economic growth from carbon emissions will require new technologies to get the job done. Some of that innovation will come from established corporations, but much of it will come from creative entrepreneurs building new products and fresh ways to power our economy. Some of those inventions are cool. Others have less sex appeal but could put a big dent in carbon emissions that are driving global weirding. Can clean-tech startups get funding in an era of fossil fuel revival? How do US clean-tech startups stack up against new ventures in China and other countries?