More than 200 of the world’s leading climate scientists will begin meeting today to finalize a landmark report summarizing how Earth’s climate has already changed, and what humans can expect for the rest of the century.

The report is the sixth edition of an assessment of the latest climate science from the Intergovernmental Panel on Climate Change (IPCC), a United Nations body that coordinates research about global warming. The last edition of this report came out in 2013 — an eternity in the world of climate science, where the pace of both warming and research are steadily accelerating.