As renewable technology continues to advance, automakers and consumers will be able to make the most out of low-emissions vehicles, which likely lead to a further drop in emissions. Experts believe much of this comes down to the way countries are powered, specifically how quickly major polluters like the U.S. transition away from non-renewable resources to more eco-friendly options. “We are projecting that with cleaning up the grid, we can reduce emissions from electric vehicles by 75%, from about 200 (grams) [7 ounces] today to about 50 grams [1.8 ounces] of CO2 per mile in 2050,” MIT Energy Initiative Senior Research Scientist Sergey Paltsev told CNBC.

Another matter to consider is the upfront environmental cost of producing EVs and hybrids, which pale in comparison to long-term light vehicle use, but are nonetheless substantial. As Politico notes, the supply chain itself would have to undergo a major shift and require the cooperation of other countries like China, which controls 80% of the world’s lithium battery supply chain. Lithium-ion battery production does indeed carry with it a cost: For example, producing a Tesla Model 3’s 75-kilowatt-hour battery at the company’s Nevada factory would result in the emission of more than 9,900 pounds. Mining raw materials also plays a role in emissions, accounting for more than 33,000 pounds of CO2 per every tonne of lithium mined using traditional methods.

Alternatives do exist and could substantially lower emissions in the mining sector. Though the EPA’s latest regulations are an encouraging sign, they also point to just how multifaceted of an issue it is to reduce emissions. The rules have the backing of prominent players like the United Auto Workers, Ford, and lawmakers like California Gov. Gavin Newsom. It’s a great start that the U.S.—and the world—can and must build upon, especially if the U.S. were to reach its EVs and hybrids goal by 2030.