[2] After the United States left the Paris Agreement, China took a leading role by hosting many of the preparatory meetings in the weeks beforehand.

On 3 December 2018, the noted British naturalist Sir David Attenborough told delegates at the conference that:[5] Right now we are facing a man-made disaster of global scale, our greatest threat in thousands of years: climate change.

If we don't take action, the collapse of our civilisations and the extinction of much of the natural world is on the horizon.On 4 December 2018, 15 year-old climate change activist Greta Thunberg addressed the summit and explained the severity of the problem this way:[6][7] What I hope we achieve at this conference is that we realise that we are facing an existential threat.

First we have to realise this and then as fast as possible do something to stop the emissions and try to save what we can save.The same day, the 14th Dalai Lama wrote to the participants of the conference: "Climate change is not a concern of just one or two nations.

The IPCC special report is a stark acknowledgment of what the consequences of global warming beyond 1.5 degrees will mean for billions of people around the world, especially those who call small island states home.

[18] The conference agreed on rules to implement the Paris Agreement, which came into force, that is to say the rulebook on how governments will measure, and report on their emissions-cutting efforts.

[19][20] Due to difficulty to reach agreement between parties, some difficult questions such as ways to scale up existing commitments on cutting emissions, ways to provide financial help for poor countries, wording that does not allow double counting and whether countries are doing enough to cut their emissions (in the light of the IPCC report) were postponed to the next conference.