At a conference dedicated to energy technology that I attended this week, I noticed an outward attitude of optimism and excitement. But it’s hard to miss the current of uncertainty just underneath. The ARPA-E Energy Innovation Summit, held this year just outside Washington, DC, gathers some of the most cutting-edge innovators working on everything from next-generation batteries to plants that can mine for metals. Researchers whose projects have received funding from ARPA-E—part of the US Department of Energy that gives money to high-risk research in energy—gather to show their results and mingle with each other, investors, and nosy journalists like yours truly. This year, though, there was an elephant in the room, and it’s the current state of the US federal government. Or maybe it’s climate change? In any case, the vibes were weird. The last time I was at this conference, two years ago, climate change was a constant refrain on stage and in conversations. The central question was undoubtedly: How do we decarbonize, generate energy, and run our lives without relying on polluting fossil fuels?

Full opinion : At an energy technology conference, climate change hardly gets a mention, and experts range from cautiously optimistic to downright nervous about the field’s future.