At this point, we still don’t know exactly what the Trump administration plans to do about the Paris climate accord — the core international treaty for dealing with global warming.

During the campaign, Donald Trump kept insisting he’d withdraw from the Paris deal as soon as possible. Except now his nominee for secretary of state, Rex Tillerson, sounds more hesitant about pulling out. “I think it’s important that the United States maintain its seat at the table in the conversation on how to address threats of climate change,” Tillerson said at his confirmation hearings. “They do require a global response.”

But even if Trump and Tillerson do end up surprising everyone and sticking with the Paris climate deal, there’s still a whole lot they could do to damage global climate talks and hinder efforts to address climate change from within. So don’t get too excited about this possible about-face just yet. In the weeks to come, we’re likely to see lots of media attention focused on whether Trump decides to pull out of Paris or not. But what he does after that is arguably just as important — maybe more so.

One good way to break this down is to look at all the different decisions around the Paris deal that the Trump administration will likely face over the next few years. Let’s go through them one by one:

1) The first big decision: Does Trump pull out of Paris?

Recall that under the Paris climate deal, agreed to in December 2015, every country on Earth has put forward an individual pledge to curb emissions. The United States pledged to cut its greenhouse gas emissions at least 26 percent below 2005 levels by 2030. China vowed to get 20 percent of its energy from low-carbon sources by 2030. And so on. These countries also agreed to meet regularly and review and strengthen their pledges, which are known as nationally determined contributions (NDCs).

But the Paris accord isn’t a legally binding treaty — it hasn’t been ratified by the Senate, and it’s effectively voluntary. So if Trump wanted, he could easily pull out, either by invoking the formal withdrawal mechanism (which would take four years) or by pulling out of the underlying United Nations Framework Convention on Climate Change (which would take one year). Or Trump could just say he plans to flatly ignore the Paris deal and doesn’t care what anyone at the UN thinks. No one could stop him.

If Trump opts for withdrawal, he’s likely to face all sorts of international condemnation and blowback. Other countries might threaten to withhold cooperation in other areas. It’d be a big ruckus. Maybe he won’t care. But it’s also possible, as Tillerson hinted, that Trump will decide it’s smarter to just stick with the Paris deal. After all, the individual pledges are voluntary. There’s no real concrete harm in sticking with it. Why not?

2) If Trump stays in, does he change or weaken the US climate goals?

Okay, let’s imagine Trump decides to stick with Paris. The media runs puff pieces about his new moderate stance. Much cheering and praise, etc. But wait! It would still be way too soon for climate advocates to declare victory.

Because the next big question is whether the Trump administration keeps in place the climate goals set by President Obama. Under the Paris agreement, countries do have the right to revise their NDCs. Trump could push to weaken America’s stated emissions goals and then brag to his supporters that he’s “negotiating a better deal.”

A move like this could, conceivably, do just as much to slow momentum around climate change as outright withdrawal would. Right now, if you add up all the current NDCs worldwide, they don’t come close to keeping us below 2°C of global warming. They add up to a very drastic 3°C or so, depending on which analysis you trust. And that’s assuming every country actually follows through on its pledges, which may not happen:

The hope with the Paris accord was always that the individual national pledges would be strengthened over time, as countries cooperated and pushed each other to increase their ambitions. By 2018, the world’s nations are supposed to formally take stock of their progress and then submit new — and ideally stronger — NDCs by 2020.

But this process of strengthening global NDCs becomes much harder if the United States is weakening its goals, or falling way short of meeting its targets because Trump has dismantled domestic climate policies. It’s easy to imagine India or China feeling less pressure to step up their efforts if the richest country on Earth is slacking off or backsliding. One could even imagine the collective global effort being weaker than it would have been if the US had simply left altogether (since the latter scenario might at least have a galvanizing effect on the rest of the world).

3) How does Trump’s team deal with the debate around transparency rules?

Next big decision! Over the next two years, negotiators will meet at the UN to hash out rules around how to actually review individual country pledges and policies. This “transparency mechanism” could prove a contentious subject. The Obama administration had long pushed for strict, uniform transparency standards. China and various developing nations, by contrast, have in the past preferred a “bifurcated” system that holds them to somewhat looser reporting requirements.

So if the Trump administration keeps a “seat at the table,” as Tillerson put it, what role does it play here? It’s possible the administration might prefer to hold China and other developing countries to the strictest transparency standards possible. But if the Trump administration is in the process weakening US emissions goals, how much influence can they plausibly wield here? Who’s going to listen to them?

This sounds like an obscure issue, but for many observers it’s one of the key looming questions around the Paris deal. After all, climate change is a collective action problem. Countries are less likely to take the plunge and push for emissions cuts unless they know everyone else will jump with them. “To me, the essence of this agreement is what it can do to strengthen confidence that everyone’s doing their fair share, primarily through greater transparency,” says Elliot Diringer, executive vice president of the Center for Climate and Energy Solutions. “With greater confidence, everyone can do more. Weaker transparency rules would make it harder to strengthen confidence and ambition over time.”

4) What does Trump’s team do about climate aid to poorer countries?

One of the other key features of the Paris accord is that wealthier nations reconfirmed a pledge to provide $100 billion in new money to help poorer developing countries both adapt to climate change and shift to cleaner energy. (These nations, after all, did the least to cause global warming but stand to suffer the most from it.) The details on where this “new money” will come from are still being sorted through, but as an early sign of good faith, rich countries promised to put up $10 billion by 2020, including $3 billion from China and $3 billion from the United States.

To date, the Obama administration has only put $500 million into the UN’s Green Climate Fund, and Republicans in Congress refuse to allocate more. (Some activists have called on Obama to take the rest from an existing State Department fund and hand it over before leaving office, but he hasn’t done so yet.)

So what does Trump do here? During his confirmation hearing, Tillerson was vague: “In consultation with the president, my expectation is that we are going to look at these things from the bottom up in terms of funds we’ve committed toward this effort.”

If, as seems quite plausible, Trump and Congress decide to abandon Obama’s funding pledge, many developing countries could potentially turn against the whole Paris deal — and the whole framework could start to fray. “For the developing countries, this will be a sign that America is unreliable and that the benefits of staying engaged in climate negotiations are fleeting,” writes David Victor, a political scientist with the University of California San Diego. “While these countries are generally not large greenhouse gas emitters, having their support is essential to making formal decisions.”

There are lots of ways to undermine the Paris deal besides leaving

The basic point here, again, is that the Paris climate deal isn’t necessarily safe just because Trump changes his mind and sticks with the agreement. These nuances of what happens to a process that’s already well underway really do matter, and there are lots of ways the US could undermine it from within.

This is why, for now, climate advocates are staying cautious about Tillerson’s “seat at the table” remarks. “It isn’t clear whether his ‘seat at the table’ will be a good dinner guest or the drunk uncle,” says Jake Schmidt, director of the international program at the Natural Resources Defense Council. “Will the US go in and try to undercut the agreement from the inside as Saudi Arabia, Venezuela, and Russia did for years, or will the US try to make sure that the rules of the agreement are as strong as possible?”

Schmidt did add a hopeful note: “I’m not sure the US wants to turn into the Saudi Arabia or Russia of the climate negotiations.” And yet, with Trump at the helm, unpredictable as ever, this is still an open question.

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