Better accounting could help. As a major fossil fuel exporter and prolific consumer of carbon-intensive imports, the U.S. is responsible for a tremendous amount of emissions that aren’t counted in standard national-level greenhouse gas totals, which generally measure emissions produced within a country’s borders. The first phase of an agreement between the U.S. and China signed this week, for instance, commits the latter to buying $52.4 billion worth of American energy—much of it in the form of oil and gas. Despite the enormous carbon footprint of U.S. businesses at home and abroad, debates on trade and climate in the U.S. have historically happened in separate sandboxes. “Domestic policy, trade policy, and climate policy all happen in their own silos, and there isn’t a lot of systematic attention being paid to how to bring those conversations together,” Todd Tucker, a political scientist and fellow at the Roosevelt Institute, told me.

Over the last 30 years, trade agreements have gotten stronger as climate deals have grown weaker. At the urging of both Republican and Democratic administrations in the U.S., the Paris Agreement swapped out the binding framework from the Kyoto Protocol for a so-called “bottom-up” system, wherein countries make voluntary commitments (“Nationally Determined Contributions”) that may eventually limit the world’s warming to “well below” two degrees Celsius (3.6 degrees Fahrenheit), instead of three or four degrees. There’s a requirement that countries present new NDCs every so often, but many can simply resubmit their original commitments rather than ratcheting up ambition during each new pledge period. Trade agreements, by contrast, generally have stringent enforcement mechanisms and create paths for corporations to challenge sovereign governments over everything from “buy local” provisions to anti-dumping laws.

While the fight for a binding United Nations climate treaty has largely been lost, many environmental activists see trade deals and potentially even bodies like the World Trade Organization as one avenue where enforcement might still be possible. Beyond encouraging more narrow measures like border carbon adjustments—fees to make the price of imports and exports reflect their carbon costs—new rules could further mandate that parties to them strengthen and live up to their commitments under the Paris Agreement or face sanctions and lose access to valuable markets.

Trade agreements have the potential to be a key mechanism by which China—now the top total emitter of greenhouse gases—is brought to the climate crisis fight, as well. The trade war President Trump initiated with Beijing hasn’t helped with that. But hawkish rhetoric from Democrats—framing decarbonization as a race against China over who can build the most clean energy—isn’t helping much either. Jonas Nahm, a political scientist at the School of Advanced International Studies at Johns Hopkins, argues for much deeper collaboration between the two countries rather than reinventing the wheel of green manufacturing. “China controls so much of the manufacturing capacity for so many of the technologies we need to combat climate change that—in the time frame that we have to make a difference—the world cannot replicate this ecosystem elsewhere. It took China 30 years to build the capacity to do this, and so now it’s making 60 percent of the world’s solar panels, nearly 70 percent of the batteries, and a third of the wind turbines,” he said. “We don’t have any of the basic ingredients that you would need to do the same thing China is doing. To try replicate that elsewhere will just delay us infinitely.”

While American progressives talk enthusiastically about ramping up green manufacturing, Nahm said that vision is “very divorced from reality right now, in terms of what we actually make.” The U.S. has little of the technical expertise, trained workers, or institutional support in place to mirror China’s booming clean manufacturing sector (itself spurred by demand from Germany’s shift to renewables) anytime soon. But by exercising massive purchasing power in the world’s renewables market, the U.S. under a Democratic administration could demand far higher labor and environmental standards across its supply chains. “If there’s a demand for products that are certified in a certain way, I’m sure manufacturers would jump on,” Nahm added.

As climate advocates look to map out a climate-friendly trade regime, they’ll have to figure out how to keep existing trade policy from undermining emissions reductions at home. Oil and gas companies have been among the most active users of the Investor-State Dispute Settlement system; according to data compiled by the U.N. Conference on Trade and Development, roughly 40 percent of international arbitration cases initiated by investors against states related to environmental and energy issues. And virtually any kind of green industrial policy could be subject to ISDS-style fights—including “almost any plank of the Green New Deal,” Todd Tucker said. Beyond climate and environmental regulations and bans on fracking, “‘Buy Local’ policies in state, local, or federal initiatives, procurement policies, subsidy schemes contingent on local production … all of that stuff would be very fair game for investment treaty complaints. Almost anything that impacts methods of production in any way would be fair game for a challenge.” All trade deals, it turns out, are climate deals.