23 September 2013 Last updated at 00:16 BST
Scientists and politicians are gathering in Stockholm this week to await the latest report from the IPCC, the UN’s Intergovernmental Panel on Climate Change.
The last report from the panel – which came out in 2007 – was considered so important that it led to the IPCC being awarded the Nobel Peace Prize, jointly with Al Gore.
The BBC’s Victoria Gill explains why this report really matters – in just 90 seconds.
Research video and graphics of Argo floats courtesy of University of California, San Diego