IPCC Report Summary
There are a lot of takeaways from the IPCC report. A big one is that we have all the tools necessary to decarbonize the economy. The IPCC report on how to tackle climate change is finally out, covering nearly 3,000 pages. Global GHG emissions are at highest ever level, but growth has slowed.
Current GHG and historical CO2 emissions are not evenly distributed. The top 10% of households are responsible for 34-45% of emissions today vs bottom half only 13-15% LDCs contributed less than 0.4% of historical CO2 and SIDs only 0.5%.
It is possible to cut emissions over a sustained period: “at least 18” countries have done so, on production AND consumption emissions basis, for “longer than 10yrs” But these reductions have only partly offset overall global emissions growth. There have been dramatic declines in cost of key techs solar (-85% 2010-2019), wind (-55%) & batteries (-85%) as well as rapidly increasing deployment Large-scale mitigation tech (not named in SPM but = nuclear, CCS) has seen “minimal cost reductions” and has “grown slowly”.
Climate policies have worked (just not fast enough) – and only 53% of global GHGs are covered by “direct” laws focused on cutting emissions Climate finance flows are up 60% but remain below the $100bn by 2020 target. Current climate policies and pledges are massively insufficient: If NDCs are followed to 2030, it is “likely” the world will pass 1.5C and there is no way to limit warming to 1.5C with “no or limited overshoot” It will also be harder to stay below 2C.
There is enough high-carbon infrastructure to blow the budget for 1.5C Staying below 1.5C or 2C would mean early retirements, retrofits with CCS Cancelling new coal is a “major option” for aligning with the cheapest route to below 2C.
Global GHGs peak around 2020 & “before 2025 at latest” in pathways to 1.5C with no or limited overshoot; current policies imply ~3.2C For 1.5C: Global GHGs fall 43% below 2019 by 2030 & 84% by 2050; CO2 -48% by 2030 & to *net-zero* in “early 2050s”; CH4 -34% by 2030. If the world cuts emissions quicker, then there is slightly more time before CO2 has to reach net-zero and we will be less reliant on CO2 removal.
There is a whole new way of categorising mitigation scenarios in AR6, from C1 (1.5C with no or limited overshoot) up to C8 (4C) There are also “illustrative mitigation pathways” showing different ways to limit warming.
For the first time, the IPCC has a chapter on demand-side mitigation including shifting diets, transport patterns and material efficiency These could cut end-use emissions 40-70% by 2050 vs baseline scenarios while improving well-being.
Climate adaptation and mitigation is “critical” to sustainable development; there are many synergies and though there are some potential trade-offs, these can be minimised. The economic benefits of limiting warming to 2C outweigh the costs “in most of the assessed literature” Looking only at the costs, mitigation for 2C would reduce annual global GDP growth by at most 0.14 percentage points (this excludes avoided damages, co-benefits etc).
Cutting emissions “requires” a “substantial reduction in overall fossil fuel use”, energy efficiency, low-emission energy sources (e.g. renewables) and alternative energy carriers (e.g. hydrogen) Renewables, EVs and efficiency would save money (blue bars on the chart)