The U.S. rejoined the Paris Agreement. Now comes the hard part

“Rejoining is just the threshold,” says Rachel Cleetus, the policy director for the climate and energy program at the Union of Concerned Scientists. “We need to do a lot more to show the world that the U.S. is going to do its fair share.”

One of the first steps is setting a new goal—a pledge that each country makes as part of the Paris Agreement. In 2015, when the Paris Agreement was created, the U.S. pledged to cut emissions 26-28% below 2005 levels by 2025. After four years of Trump dismantling climate policy, we’re not on track to meet that goal. To make things more difficult, the goal now also needs to be much more ambitious: In 2018, a U.N. report warned that it was critical to limit global warming to 1.5 degrees Celsius, and to do that, emissions need to drop nearly in half by 2030. Biden needs to set a target, called a “nationally determined contribution,” to cut emissions by 45-50% by the end of the decade. Then we need the policy to actually make that happen.

While the new administration can accomplish several things directly—including reversing dozens of environmental rollbacks from the Trump administration—it’s also important for Congress to pass new laws. “There are limits to what the administration can do on its own,” says Cleetus. “Especially if we’re going to have durable policy that lasts beyond the term of any one administration or Congress.” The U.S. can’t credibly put forward a goal like cutting emissions by 50%, she says, without the support of Congress. Here are a few of the key policies that the government could pursue.

100% clean power by 2035

One of Biden’s campaign promises was to create a “carbon pollution-free power sector” by 2035, as part of a $2 trillion investment to build back the economy by investing in green infrastructure. The country is already moving quickly to renewable electricity, in part because so many states have mandated a transition. In many parts of the country, new solar and wind power is now cheaper than power from fossil fuels. The next step is for the U.S. to have a national renewable energy standard that ramps up the percentage of clean power we need over time. “It’s a policy that already exists for one in more than one in three Americans,” says Leah Stokes, a political science professor at the University of California Santa Barbara who focuses on energy, climate, and environmental politics. “It’s not some crazy new idea.” Colorado, for example, already has a goal for 80% clean power by 2030, which is on track for fully clean power by 2035. If Congress passes a similar law, “that would create momentum throughout the entire country, so that all our decision-makers like electric utilities would be moving in that direction at the pace and scale that’s necessary,” she says. The country also needs to build out new infrastructure for the electric grid, which can help add new jobs as the economy rebuilds from the pandemic.

Scale up electric cars

Electric vehicles are on the verge of being as cheap to buy as gas-fueled cars. But they’re still a tiny fraction of total car sales in the U.S. now. Policy can change that, as it has in Norway, where electric cars made up 54.3% of car sales in 2020 because of strong government incentives and support for charging infrastructure. “Congress passed an energy omnibus bill at the very end of last year that had a lot of great energy provisions in it, but the key missing ingredient was electric vehicle deployment support,” says Stokes. “We’re not at all at the pace that’s necessary when it comes to electric vehicle adoption.” As the electric grid eliminates emissions, running electric vehicles will also be emissions-free.

Retrofit buildings

Buildings are another major source of emissions, and another Biden campaign promise was to retrofit four million buildings and weatherize two million homes to help save energy. The government can also help give people incentives to switch to technology like geothermal heat or replace their gas stoves with induction ranges. “That kind of the approach would be transformative because very few people at this point are thinking about getting fossil fuels out of their home,” she says. “That’s totally necessary, not just for the climate, but also for their own health, because it’s becoming increasingly clear that living in a home with a gas stove is putting enormous amounts of pollutants in the air.”

R&D for hard-to-decarbonize industries

The government can also help support new technology for industries that can’t yet easily get rid of emissions, like steel manufacturing. That’s important, because the entire economy needs to get to net-zero emissions by 2050. Still, Stokes says, scaling up the technology that we already have, such as renewable electricity and electric cars, can get us the majority of the way to the 2030 goal.

The Paris Agreement, on its own, isn’t enough; even though nearly all of the world’s countries stayed in the deal when the U.S. dropped out, they’re not moving fast enough to actually meet the agreement’s goals. “The globe is procrastinating on a really big problem,” says Stokes. “And we’re already starting to pay for that the consequences of that procrastination through billion-dollar storms that are hitting the United States, more and more times each year, through global heatwaves, huge typhoons. The costs are mounting every year, and we can’t continue to procrastinate. And countries are really not taking this on at the scale that’s necessary.”

The U.S. now has the opportunity to help lead in the right direction. (That includes making good on payments the Obama administration promised to low-income countries to tackle climate change, which Trump later withdrew.) “This is a very hopeful moment,” says Cleetus. “This is a really a different tone. We’re hearing that science will be centered, equity and justice will be centered, that we are once again going to engage with a global community as a partner and an ally. It is such a hopeful moment.”