Climate Change, and attempting to reach some sort of agreement which would halt the predicted 2 degree rise in temperature which would result in significant degradation of natural systems.
The meeting was called COP21.
It appears from the news on the BBC tonight that an agreement has been reached, which could aim to keep the rise to below 2 degrees, and as close as possible to 1.5 degrees, and require action from countries around the world.
This is by no means guaranteed to work, but without some sort of coordinated effort, it seems inevitable that there will be some significant issues in the future.
The Paris agreement apparently still needs to be signed in a plenary session. There is plenty of coverage in all the newspapers at the moment and on their websites.
I've been following the coverage of a group called CarbonBrief, whose director is Leo Hickman. Three years ago, he and I were among the speakers at a conference at the International School of Geneva on the theme of sustainable futures. You can read my posts on my contribution here. I talked about Water security.
I wait to see how this story will develop.
The agreement has been signed.
George Monbiot isn't so sure about what has been achieved.