Carbon budget for 1.5°C runs out in 6 years at current emissions levels
The world has just six years to get to net zero, according to new calculations.
The calculations show that if humanity wants to have a 50-50 chance of limiting global warming to 1.5°C, we can only emit another 250 gigatonnes (billion metric tonnes) of CO2.
Global emissions are currently at 40 gigatonnes of CO2 per year.And, as this figure was calculated from the start of 2023, the time limit may be actually closer to five years.
Researchers behind the new results revised the remaining carbon budget down from the 500 gigatonnes reported by the the IPCC from the start of 2020. That's partly timing: three years and 120 gigatonnes of CO2 emissions later, the world is closer to the 1.5°C threshold.
Many aspects of the estimate are uncertain.The balance of non-CO2 pollutants in future emissions scenarios will influence the remaining carbon budget.Plus, it's not yet clear whether warming will actually stop at net zero or take decades to slow.
These uncertainties are why the researchers quote a 50/50 likelihood of limiting warming to 1.5°C at 250 gigatonnes of CO2.A more risk-averse assessment would report a 2 in 3 chance of staying under 1.5°C with one-and-a-half years of current emissions left.