Joe Biden answers student questions on climate change, young workforce at University of Iowa

“It’s the single biggest issue facing humanity,” he said.

He added he would rejoin Paris Climate Accord, call on more than 200 countries to meet in the U.S. to establish enforcement mechanisms for the agreement, invest research into a “carbon-free atmosphere,” increase tax credits for wind and solar, reform mileage standards, install electric car recharging stations and  electric rails across the U.S. and within cities.

He said Obama called him “Amtrak Joe” as a reference to his support for rail infrastructure. His climate stance is similar to other Democratic candidates in the race, but Biden does differ on his stance on fracking. Biden doesn’t support a nationwide ban on fracking, which is an oil and natural gas extraction technique by fracturing rock with a pressurized liquid.