The rate at which atmospheric CO2 is increasing is now outpacing the pathways set out by the Intergovernmental Panel on Climate Change (IPCC) that limit global warming to 1.5C.
The third working group report of the #IPCC’s sixth assessment report (#AR6), published in 2022, presented a set of seven “illustrative pathways” that highlight how different mitigation choices across major economic sectors translate into future #GreenhouseGas #emissions and global temperatures.
In the three most-ambitious pathways, #GlobalWarming has a 50% chance of either staying below 1.5C, or overshooting it by only 0.1C (for up to several decades) before then returning to below 1.5C.
Yet, not only are atmospheric #CO2 concentrations still rising, the rate of rise is #accelerating.
The build-up of CO2 in the #atmosphere has been monitored at the #MaunaLoa observatory in #Hawaii since 1958.
As illustrated by the iconic #KeelingCurve below, the increase has been accelerating over the decades (blue line) due to ongoing emissions of CO2 from burning #FossilFuels and changing land use.
So while the curve needs to rapidly bend in the other direction to hold warming to 1.5C (light red line), the rate of rising CO2 marches onwards and upwards.
https://www.carbonbrief.org/met-office-atmospheric-co2-rise-now-exceeding-ipcc-1-5c-pathways/
