Exiting the fossil fuel economy is unlikely before 2050, but with temperature already at 1.1°C above pre-industrial temperature, it is likely Earth will cross the 1.5°C guardrail by 2040. The authors conclude this alone defines an emergency.
Nine active tipping points:
- Arctic sea ice
- Greenland ice sheet
- Boreal forests
- Atlantic Meridional Overturning Circulation
- Amazon rainforest
- Warm-water corals
- West Antarctic Ice Sheet
- Parts of East Antarctica
The collapse of major ice sheets on Greenland, West Antarctica and part of East Antarctica would commit the world to around 10 metres of irreversible sea-level rise.
Reducing emissions could slow this process, allowing more time for low-lying populations to move.