The new Forster et al paper led to some confusion on the topic of warming acceleration.
Here's their GWI calculation of human contribution to the decadal rate of warming. We see a recent uptick to ~0.26C/decade, ~50% higher than the ~0.18C for most of the period since 1970.
In the abstract they were pretty clear that "human-induced warming has been increasing at a rate that is unprecedented in the instrumental record, reaching 0.26 [0.2–0.4] °C per decade over 2014–2023."
However, the error bars are pretty large here; its hard to say based on the model they use here that current rates are unambiguously higher than those experienced in the 90s and 2000s.
We can also dig into drivers of these rates.
If we look solely at warming from GHGs, the rate of warming would be pretty consistent. However, changes in other human forcings (primarily aerosols) led to slower warming rates early on and faster rates in recent years.
At the same time, the paper compares the period assessed by the IPCC (2010-2019) and the period assessed in the new paper (2014-2023). Here they see no evidence of faster rates of warming in the more recent period across most approaches:
So the paper really provides different answers to two questions:
1) Is the world warming faster now than the rate we've seen since the 1970s? Probably yes.
2) Is there evidence of acceleration in the past few years? Probably no, though its hard to draw firm conclusions from such a short period.
Add to the non-linear expansion of marine heatwaves further drying out continents,cloud feedback,further sea ice losses at both poles, warming in the pipeline being increasingly released by the oceans,maybe a reduced heat uptake by the oceans, and an extreme El Nino and 2°C by 2030 are a possibility
Sure all this is controversial discussed but guess the above will prevail
And SOx emission cuts in 2020 over the shipping routes are out to a large extent for the warming in 2023
Sadly from a mechanistic perspective warming is now accelerating substantially
- marine heatwaves now starting to be discussed as a feedback of warming
- MHWs and drying out continents produced the shortwave feedback in 2023
- cloud reduction contributed some 0.2°C to the warming in 2023
