When the Paris Agreement goes into effect on November 4, the Eiffel Tower and the Arc de Triomphe will be lit green in celebration, Keith Bradsher explains for The New York Times. But when the celebrations end, the real work begins as policymakers, investors, and businessmen figure out the details on what it will take to meet the deal’s goals on keeping global warming below 2 degrees Celsius.

As Bradsher explains, uncertainty runs deep on implementation of the climate accord — many companies have not even begun to measure their greenhouse gas emissions, let alone take steps to reduce them, while the financial framework of a carbon price or tax has only started to emerge.

Bradsher reports that “[t]he Paris Agreement, reached in December among 195 countries, was never imagined as the silver bullet for global warming. Rather, the goal of the agreement was to stave off the most devastating effects of climate change by limiting the increase in global temperatures to two degrees Celsius, and to just 1.5 degrees Celsius if possible.

But even that may prove problematic. If every country fully accomplishes its initial pledges, the increase would be closer to 2.7 degrees.”