The world is not ready for the impacts of climate change, including more extreme weather and the likelihood that populated parts of the planet could be rendered uninhabitable, says the planet's leading body of climate scientists in a major new UN report.

The 772 scientists who wrote and edited the report argue that world leaders have only a few years left to reduce carbon emissions enough to avoid catastrophic warming, which would produce significant sea level rise and large-scale shifts in temperatures that would dramatically disrupt human life and natural ecosystems.

"Observed impacts of climate change are widespread and consequential," according to the report, which is from the UN's Intergovernmental Panel on Climate Change (IPCC) and was released Monday morning