The latest generation of climate models are somewhat warmer...
* RCP2.6 was ~1.7°C in 2100 (66% below 2°C), but SSP1-2.6 is ~2.1°C.
* RCP8.5 was ~4.6°C in 2100, but SSP5-8.5 is up to 5.5°C
* The middle scenarios are ~0.5°C warming in 2100
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#COP25 carbonbrief.org/cmip6-the-next…
* RCP2.6 was ~1.7°C in 2100 (66% below 2°C), but SSP1-2.6 is ~2.1°C.
* RCP8.5 was ~4.6°C in 2100, but SSP5-8.5 is up to 5.5°C
* The middle scenarios are ~0.5°C warming in 2100
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#COP25 carbonbrief.org/cmip6-the-next…
The new scenario SSP1-1.9 was supposed to be below 1.5°C in 2100, but it is so far 1.6°C in 2100...
Only partial results in , but worth noting frequency of models
* SSP2-4.5: 14 models
* SSP5-8.5: 13 models
* SSP1-2.6: 12 models
(see numbers at bottom in brackets)
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Only partial results in , but worth noting frequency of models
* SSP2-4.5: 14 models
* SSP5-8.5: 13 models
* SSP1-2.6: 12 models
(see numbers at bottom in brackets)
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The new generation of models give equally good fit to observations as CMIP5, but they are warmer as we go into the future...
It will be interesting to see a decomposition of results, in due course, to see why some models are warmer than earlier versions...
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It will be interesting to see a decomposition of results, in due course, to see why some models are warmer than earlier versions...
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It is worth noting that the new scenarios (the so called SSPs) are not identical to the RCPs, despite giving the same forcing levels in 2100.
Some of the differences between CMIP5 & CMIP6 could be down to input SSP/RCPs, & this should be easy & critical to assess?
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Some of the differences between CMIP5 & CMIP6 could be down to input SSP/RCPs, & this should be easy & critical to assess?
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The CMIP6 models generally have higher climate sensitivity than in CMIP5.
9 models, highlighted in yellow, have an ECS above 4.5°C (top of the IPCC likely range) & 7 of these have sensitivities above the highest model in CMIP5!
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9 models, highlighted in yellow, have an ECS above 4.5°C (top of the IPCC likely range) & 7 of these have sensitivities above the highest model in CMIP5!
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CMIP6 results are starting to trickle in & we have only sparse explanations. CMIP6 will likely run long after IPCC AR6 is finished & explanations will trickle in for years to come.
We should be careful to over interpret the initial findings, as there could be explanations.
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We should be careful to over interpret the initial findings, as there could be explanations.
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Read the @CarbonBrief explainer carbonbrief.org/cmip6-the-next… & the excellent thread by @hausfath
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