Electric cars are surging in popularity, creating the hope that -- even in the absence of pro-climate legislation in the U.S. -- the automobile's contribution to global warming can be limited.
But when it comes to other types of transport, it's a different situation. "We're not going to be flying on an electric vehicle for quite a while," said chemist Jennifer Holmgren, who runs a company called LanzaTech.
Air travel, along with shipping, is facing calls to tamp down the amount of emissions it produces, which have been increasing twice as fast as carbon emissions in general. And one way the industry is looking to reduce its impact is with a product LanzaTech developed: bacteria poop.
The product, to be precise, is recycled ethanol -- created from smokestack emissions that have been processed by specially modified microorganisms. LanzaTech's founder and chief science officer, Sean Simpson, has been developing this technology since 2005. Last year, Virgin airlines announced that it would use LanzaTech's ethanol fuel in some of its flights, reducing their overall emissions by 60 percent. The first flight is set to take place sometime in 2018.
Using recycled carbon has two benefits. It removes the need to extract oil or gas from the ground, and it effectively captures pollutants that would otherwise seep into the air and contribute to global warming.
LanzaTech takes pollutants directly out of smokestacks: A compressor attached to the stack captures the gases, which then go through a processing method to make them accessible to bacteria. The bacteria, which have been modified to eat those gases, then turn them into ethanol. Holmgren compares the process to the fermentation of sugar to create alcohol.
"You can put the ethanol in your car. You can convert it into polyethylene to make bottles from it. You can convert the ethanol to jet fuel," she said. "Someday, we hope to make specialty chemicals. Someday, I hope your yoga pants will be made from recycled carbon." (Polyethylene is an ingredient in spandex, the substance that makes fabrics stretchy.)
LanzaTech has already raised more than $250 million from investors including Khosla Ventures, K1W1, Mitsui and the New Zealand Superannuation Fund. (The company was founded in New Zealand, and it's now headquartered in Skokie, Illinois.)
"What I love about our technology is that it makes economic sense," Holmgren said.
"We don't have to argue about whether doing something good for the environment is at odds with making money or creating jobs -- we can do both."
LanzaTech receives royalties from customers that use its technology to produce ethanol, getting a set price for every ton produced. The customers make money by selling the ethanol as fuel, or potentially as an ingredient for plastic. Few other costs are involved because the only input is the customer's own emissions.
Last year, LanzaTech got its first North America customer when Aemetis, a traditional ethanol plant, licensed LanzaTech's technology. The agreement means Aemetis will develop ethanol from waste, not from corn, which most ethanol is made from.
"I would love to create a carbon-smart world," Holmgren said, where "there's a carbon-recycled pair of yoga pants, and just a pair of yoga pants. And you as the consumer can say, 'I want that one. I want the carbon-smart pair of pants."