Steven Chu, U.S. Secretary of Eergy and Nobel Laureate: Climate change is real, and it’s happening now. “There is compelling evidence that Earth’s climate is changing and humans are responsible for it. We only have one chance at correcting it and we have to do it,” Chu presented decades of satellite data that show how human activities are affecting the global climate pattern. “Glacier melting is accelerating and the sea level is rising,” The good news is that new technological solutions are being developed in the area of air filtration using HEPA filters and novel techniques that trap particles using electric charge. He predicts the price of solar-generated electricity will continue to drop from 3 cents per kilowatt-hour in 2020 to 2 cents per kWh by 2035 or 2040.