The world is choking in plastic trash, and the UN wants to do something to fix it.

A weeklong meeting of the Intergovernmental Negotiating Committee (INC) on Plastic Pollution in Punta del Este, Uruguay, ended last Friday (Dec. 2). It was a first, formal step towards a legally binding international treaty to deal with the global plastics problem. Such a pact would be the most consequential environmental treaty in years, on par with 2015’s Paris Agreement on climate change.

The INC will spend the next two years negotiating how binding the regulations will be. While most of the 1,800 attendees in Uruguay ostensibly support ending plastic pollution as a baseline, competing motives have factions pulling in different directions. Hardline countries and campaigners are pushing for outright bans on “problem plastics” and certain chemicals, as well as internationally set regulations and strict production monitoring.