UN report on climate change: World leaders called on to act

The IPCC report envisions five different scenarios. Under the worst, carbon emissions continue to increase. Under the best, the world experiences large and quick pollution cuts. But in every scenario, the planet would still exceed a crucial warming threshold by the 2030s.

UN report on climate change: 5 things to know

In a report released Monday, the independent experts on the U.N.-appointed Intergovernmental Panel on Climate Change agreed that almost all warming since pre-industrial times was caused by the release of heat-trapping gases such as carbon dioxide and methane.