The most recently submitted nationally determined contributions (NDCs) to the Paris climate agreement only narrowly reduce expected global warming by the end of this century and remain well below what is required to limit global warming to 1.5°C above pre-industrial levels, the UN said yesterday.
Global warming remains on track for a 2.7°C rise this century against pre-industrial levels on the basis of the latest updates to unconditional NDCs, the UN finds in a preliminary assessment updating its recently published Emissions Gap Report.
This is the same as the estimate put forward by the UN in its initial report published last month, which assesses the difference between the forecast level of emissions under current policies and where they need to be to avoid the most severe impacts of climate change.
If conditional NDCs are also fully implemented, global warming would be likely to be limited to 2.5°C, compared with an estimate of 2.6°C in the original report. The estimates are similar "due to limited changes to 2030 emissions", the UN said.
"Even considering the recent updated pledges for 2030, annual global [greenhouse gas] GHG emissions would need to be roughly halved by 2030 to become consistent with a 1.5°C least-cost pathway," the UN warned.
The UN now expects warming to be limited to 2.1°C alongside full unconditional NDC implementation, or 1.9°C with conditional NDCs, and assuming that all net zero pledges and announcements are fully implemented. The impact of the net zero commitments on top of the NDCs limits warming by 0.6-0.8°C from the 2.7°C rise — the UN had previously said that net zero commitments would limit warming by 0.5°C.
But it reiterates its previous warning that the achievement of net zero is uncertain, "given the lack of transparency of net zero pledges, the absence of a reporting and verification system and the fact that few 2030 pledges put countries on a clear path to net zero emissions".
The IEA said last week that if all the climate pledges to date, including those announced at the UN Cop 26 climate conference currently taking place in Glasgow, are implemented "in full and on time" it would be sufficient to limit global warming to 1.8°C this century.
But speaking at a Cop 26 side event today, the co-chair of the UN Intergovernmental Panel on Climate Change's Working Group III, Jim Skea, warned that while the pledges are "moving us in the right direction", there is not enough evidence to make the statement that they will limit warming to 1.8°C.
