Last week I reviewed how @IEA WEO 2019 scenarios suggest today’s policies are moving the world well away from >3˚ and now we’re tracking closer to 2˚ than ever ➡️ but does that claim stand up if we look at explicit IPCC climate policy scenarios more closely? Thread ⬇️ 1/6 
📈➡️ 2040 both the IEA Current Policies Scenario (CPS) and IEA Stated Policies Scenario (SPS) are consistently aligned with outlooks for energy/industry CO2 emissions that do not exceed RCP4.5 ▶️ RCP4.5 is associated with +2.6˚C warming by 2100 vs. pre-industrial baseline - 2/6
How about lower levels of climate change? ➡️ 2040 the IEA CPS is in the upper range of IPCC scenarios consistent with RCP3.4 and the IEA SPS is lower than all but one SSP scenario that exceeds RCP3.4 - The RCP3.4 scenario expects +2.2˚C by 2100 - 3/6
How about below 2˚? The IEA SPS is only following very few of the scenarios associated with a policy target of RCP2.6, and the IEA CPS is definitively above this threshold. Therefore, neither scenario is consistent with unambiguously keeping warming below 2˚C by 2100 - 4/6
However, the IEA Sustainable Development Scenario (SDS) is definitely well-positioned inside the range consistent with RCP2.6, and even some of the SSP RCP1.9 scenarios that would aim to limit warming below 1.5˚C - 5/6
Where are we headed ➡️ 2040? More evidence world tracking toward the IEA Stated Policies Scenario which is closest to climate scenarios consistent with just above +2˚C by 2100; IEA indicates energy sector tech/policy pathway not as far off 2˚ as some have previously thought - 7/7
Subthread ⬇️: IEA CPS aligns with IPCC scenarios expecting +2.2-3.0˚C but clearly diverging from baseline scenarios >3˚C used to study possible no climate policy futures; makes sense because IEA scenarios include today’s energy and climate policies & IPCC baselines do not - S1/6
All of this is interesting in the context of a snapshot for 2040, but what would IEA scenarios need to do to stay on track toward 2˚ or lower in the following decades? That will take another thread next month. - S2/6
We’re only talking about energy/industry CO2 emissions here, not all GHGs - comparisons to the recent WMO GHG Emissions Gap report would also need another thread, but here’s a good one: per @hausfath - S3/6
All this said, no policy baseline scenarios used by the IPCC like RCP7.0 and RCP8.5 include no climate policies by definition and a limited representation of energy policies. This has been a practical thought experiment for comparing models in the academic literature… - S4/6
…but that concept is having difficulty translating in a meaningful way to today’s world… a world the IEA says is making such no policy baseline pathways look far less realistic. If the IEA is underestimating CO2 emissions by 2040, are they really underestimating >50%? - S5/6
Is there any logic to support such ⬆️ underestimation? Especially when there are so many with a strong rationale that IEA CPS may be too bullish on fossil consumption + world coal faces so many headwinds summarized by recent @CarbonBrief article? - S6/6
