Climate change negotiators gathering for the first time since hammering out the Paris Agreement faced an unexpected quandary – preparing for the agreement to formally take effect so quickly.

The agreement is intended to guide climate efforts starting in 2020, and originally it was expected it would take a few years for governments to complete their ratification processes and formally bring the treaty “into force.”

But when it was ceremonially “opened for signature” last month in New York, an astounding 175 countries signed. And with the United States and China declaring they will go the next step and formally join the agreement later this year, it’s looking very likely the threshold for entry into force will be cleared next year if not sooner (55 countries representing at least 55 percent of global emissions must formally consent).

This is great news. It shows that the tremendous political momentum that produced the agreement in December is still going strong – even if it is complicating life a bit for the teams of negotiators who now must flesh out the broad Paris architecture with a set of more detailed implementing decisions.

The unanticipated issue is how to ensure that countries that aren’t able to formally join as quickly can still have a hand in shaping the implementing decisions once the agreement enters into force. The lawyers have identified potential fixes and the issue should be ironed out at COP 22 this November in Marrakech, Morocco.

Beyond that, the negotiators are just beginning to grapple with a host of technically and politically challenging design issues – for instance, the specifics of the transparency system that will keep countries accountable, and of the every-five-years cycles for assessing collective progress and updating countries’ national contributions.

The two-week meeting just wrapping up Bonn, Germany, where the United Nations climate secretariat is headquartered, was largely about getting the post-Paris process organized.

Following the frenzied rounds of talks leading up to and culminating in Paris, there were signs of negotiating fatigue. But the “Paris spirit” by and large prevailed, with parties working through their differences about the process going forward.

The more substantive discussions during the second week foreshadowed some of the challenges ahead in fleshing out the Paris framework. One of the trickiest will be sorting out exactly how to apply Paris’ more nuanced approach to differentiating responsibilities among countries, which replaces the Kyoto Protocol’s stark divide between developed and developing countries.

However quickly the Paris Agreement formally enters into force, it will likely take until 2018 to complete the implementing decisions. Continued high-level political attention can help ensure that the negotiations stay on track – and, perhaps more importantly, that countries push forward with the domestic policies needed to deliver on their commitments.