The Brisbane Times reports:
Humans have already released half the total carbon dioxide emissions permissible before the planet is at risk of warming to dangerous levels, a draft United Nations scientific assessment says.
The final draft of a major assessment by the Intergovernmental Panel on Climate Change suggests that keeping warming to 2 degrees – regarded as a guard-rail against the worst impacts of climate change – will require deep global emissions cuts in coming decades.
Under the future emissions scenarios considered by the IPCC, only the most stringent would keep the world within the remaining CO2 allowance for 2 degrees. It would mean an average global emission cut of 50 per cent by mid-century on 1990 levels, and possibly require removal of carbon dioxide from the atmosphere by 2100.