Emissions are no longer following the worst case scenario
If you step back in time to 2014, global CO2 emission told a pretty frightening story. Emissions had rapidly increased at a rate of 3% per year in the 2000s, and there was not much sign yet of a slowdown in the early 2010s. Global emissions appeared to be following the worst case (RCP8.5) scenario.
Global CO2 emissions (both fossil and land use) have been relatively flat during the 13 years after 2010, and are now closer to the middle-of-the-road RCP4.5 scenario than the high-end RCP8.5 one 1. This is even more clear if we look at fossil CO2, which is the most important factor in long-term growth (as its responsible for 90%+ of future emissions in high-end scenarios).
This is due to the rapidly accelerating energy transition driven by falling costs of clean energy technologies, that has led to a stagnation of global coal use. The world spent $1.1 trillion dollars on clean energy technologies in 2022, up from around $780 billion in 2021 and $600 billion in 2020, a trend that shows no sign of slowing down.
Even more importantly, there is a growing consensus in the literature that global emissions are likely to remain flat even in the absence of strong climate policies enacted by countries. The figure below is from the IPCC 6th Assessment Report Synthesis, and shows the range of assessed current policy projections for global CO2 emissions in red (along with a somewhat arbitrary selected marker scenario in with a solid red line).
