ASSOCIATED PRESS Some of the city of Pittsburgh's fleet of electrical vehicles parked under solar charging panels.

Just days after carbon dioxide concentrations in the atmosphere hit a level not seen in 800,000 years, Sen. Jeff Merkley (D-Ore.) is proposing a bill to completely phase out new gas-burning cars by 2040. The legislation mandates zero-emissions vehicles to make up 50% of new sales by 2030, and ratchets up the requirement 5% every year for a decade. Merkley plans to submit the bill on the Senate floor Wednesday. It’s an ambitious proposal, and one almost certain to go nowhere in a Republican-controlled Senate and under an administration that’s in the process of reversing rules to make combustion-engine vehicles more fuel efficient. The bill is almost identical to legislation Merkley introduced in November in the last Congress. What’s changed is the political framework into which it now fits. Over the past six months, the Green New Deal has emerged as a new guiding vision for climate policy, calling for a decadelong industrial plan to zero out emissions, fortify infrastructure and eliminate poverty with millions of union-wage jobs. But while the movement is fast becoming a major political force, particularly ahead of the 2020 Democratic primaries, the Green New Deal’s proponents have yet to produce any actual policy. “When I take a lungful of air in this moment, it has 30% more carbon in it than when I was born,” Merkley told HuffPost. “That is a change that has never happened in a single generation of humankind on this planet.” The zero-emissions vehicle bill offers one example of what policy to cut emissions from transportation, the United States’ largest source of planet-warming gases, could look like. “This is just one small contributor to that vision,” Merkley said. “But we need to develop the details around many ideas so those ideas are ready to be combined into a larger package.”

Alex Wroblewski via Getty Images Sen. Jeff Merkley (D-Ore.) first introduced the zero-emission vehicle bill last year.

Far from the Green New Deal’s revolutionary clarion calls, the bill does the unsexy work of translating popular state programs into national policy. The legislation works by providing zero-emission vehicle credits to manufacturers. Those credits make it so each car sold earns a certain number of credits based on the battery range and type of zero-emission vehicle, according to a Union of Concerned Scientists factsheet. For example, hybrid vehicles earn a partial credit, while all-electric cars earn a full credit. The bill sets a minimum percentage of new car sales required to be covered by credits, and ramps that figure up annually until 2040, at which point all new vehicles sold would need to meet the mandate. Because the nation’s car fleet turns over every decade, the bill would ostensibly take nearly all fossil-fueled cars off the road by 2050. That’s far slower than what’s needed to keep average global temperatures from rising another half a degree to 1.5 degrees Celsius, or 2.7 degrees Fahrenheit, at which point the United Nations’ Intergovernmental Panel on Climate Change predicts extreme weather and sea level rise will cause at least $54 trillion in damages and cost millions of lives. And the bill doesn’t address emissions from trucks or heavy-duty vehicles. But Merkley said the bill is meant to be a starting point based on existing state policy, and the requirements under this legislation already set a faster timeline than what California requires. “The faster it can be done the better,” he said. “If the world changes fast enough, and we can move even faster, then great.” As it is, the legislation proposes phasing out combustion-engine vehicles faster than worldwide market trends are forecast to do so. By 2040, electric vehicles are forecast to make up 57% of global passenger car sales, according to the research firm BloombergNEF’s latest annual outlook, published Wednesday. Heavy trucks, the analysis found, “will prove the hardest segment for electrics to crack” with a much lower 19% of total sales in 2040. Sens. Sheldon Whitehouse (D-R.I.), Brian Schatz (D-Hawaii), Kamala Harris (D-Calif.), Kirsten Gillibrand (D-N.Y.) and Bernie Sanders (I-Vt.), the latter three of whom are candidates for president, co-sponsored the bill. Rep. Mike Levin (D-Calif.) plans to introduce champion legislation in the House. “If we can’t get a larger package, but we can get individual pieces like electric cars, buses, better insulation, then we should do that, too,” Merkley said. “We need to push at every level.”

When I take a lungful of air in this moment, it has 30% more carbon in it than when I was born. That is a change that has never happened in a single generation of humankind on this planet. Sen. Jeff Merkley (D-Ore.)