During his turbulent and controversial candidacy, United States President-elect Donald J. Trump put forward relatively few concrete policy proposals. Vague promises of renegotiating trade deals, funding infrastructure projects, and returning the country to a past state of ill-defined greatness were rarely accompanied by anything substantial enough to call a plan.

There were, however, several concrete initiatives hidden in Mr. Trump’s tangle of hollow reassurances. Notably, the President-elect promised to “cancel” the Paris Agreement within his first hundred days in office. He said so loudly and repeatedly, and participants in the COP 22 have every reason to believe that his intentions are honest. After all, the billionaire businessman has called climate change a hoax perpetuated by the Chinese.

The question on concerned parties’ minds, then, is whether it is possible for a Mr. Trump to pull out of the landmark international Agreement to reduce domestic carbon emissions. If so, how long would it take? Would he need consent of the Senate? Would there be repercussions?

The Paris Agreement reached last year at COP 21 is part of the United Nations Framework Convention on Climate Change (UNFCCC), a treaty signed by President George H. W. Bush in 1992. Within this framework, there are several possible scenarios under which Mr. Trump could fulfill his campaign promise of effectively “cancelling” America’s commitment to the Paris Agreement.

The first scenario under which President Trump could release the United States of its Paris obligations would be to follow the withdrawal provisions found in Article 28 of the Agreement. This by-the-book withdrawal takes at least four years, and the earliest the United States could exit would be November 2020. Of course, given Mr. Trump’s pledge to exit the Agreement within one hundred days, this legally sanctioned path is an unlikely choice.

If Trump did opt for this route, there is an open question as to whether the Paris Agreement would survive after 2020, since the 55% emissions threshold for the Agreement to enter into force would no longer be met. If the 55% threshold is interpreted to apply only to the ratification of the Agreement, it would likely stay in force since it has already been ratified. If, however, the 55% threshold was interpreted to apply to continuity of the Agreement, it would likely lose all credibility under international law once the United States withdrew.

Another way President Trump could withdraw from the Paris Agreement is to withdraw the UNFCCC altogether. International law requires at least one full year to exit a treaty. If Mr. Trump decided to cancel the United States’ signature on the entire Treaty, the country would not only be released from the Paris Agreement, but from the Montreal Protocol and other past COP agreements as well. It would leave behind almost 200 fellow countries still party to the Treaty.

The timelines for the both of the above paths – four years to withdraw from the Paris agreement and one year to withdraw from UNFCCC – are dictated by international law. Unfortunately (in this case), international law has no enforcement mechanisms other than economic sanctions and diplomatic reproach. It is quite possible that neither of these soft sticks would deter the callous and bombastic President-elect from declaring immediate withdrawal in direct violation of international law.

Following a third possible path, President Trump could officially stay party to both the Treaty and the Agreement but simply ignore the obligations they impose. The framework of the Paris Agreement offers little teeth by way of enforcement, especially against an entity as economically and diplomatically powerful as the United States. In some ways this is the best-case scenario under which the new President could avoid Paris obligations: United States would remain a party under international law and Mr. Trump’s successor could pick up where Obama left off regarding emissions reductions, without having to go through the hoops of reentering UNFCCC and the Paris Agreement. Four years of inaction are certainly better than four years of affirmative withdrawal from international climate obligations.

International law aside, there are domestic legal questions regarding Mr. Trump’s ability to unilaterally withdraw from either the Agreement or the Treaty. UNFCCC was ratified in 1992 with the advice and consent (two-thirds) of the Senate, as required by Article II the Constitution. The Constitution is silent, however, on the mechanisms of withdrawal from a treaty. It would be reasonable to assume that if the domestic ratification of treaty requires Senate approval, withdrawal does too. Others could argue, however, that withdrawal remains within the sole jurisdiction of the executive branch. Precedent points to the former interpretation of the Constitution’s silence, but the Supreme Court has never definitively spoken on the issue.

Clearly these are areas of concern for those attending the COP 22 in Marrakech. However, the will of the participants is resolute: already there have been calls to march forward in the decades-old climate negotiation process with or without the Convention’s biggest polluter. While a climate treaty without United States’ participation seems like a grim prospect, the international climate change community is no stranger to setbacks. The dedication of the people at this Conference to addressing the disastrous social and economic impacts of a changing climate will far outlive the vagary of Donald J. Trump.

This post was a contribution of Reed McCalib, one of our Week 2 delegates. Check back soon for more updates from our second group of delegates!