Updated nationally determined contributions collectively raise ambition levels but need strengthening further to keep Paris goals within reach

Abstract

By January 2022, 156 countries had submitted new or updated nationally determined contributions (NDCs) under the Paris Agreement. This study analyses the greenhouse gas (GHG) emissions and macroeconomic impacts of the new NDCs. The total impact of the updated unconditional and conditional NDCs of these countries on global emission levels by 2030 is an additional reduction of about 3.8 and 3.9 GtCO₂eq, respectively, compared to the previously submitted NDCs as of October 2020. However, this total reduction must be about three times greater to be consistent with keeping global temperature increase to well below 2 °C, and even seven times greater for 1.5 °C. Nine G20 economies have pledged stronger emission reduction targets for 2030 in their updated NDCs, leading to additional aggregated GHG emission reductions of about 3.3 GtCO₂eq, compared to those in the previous NDCs. The socio-economic impacts of the updated NDCs are limited in major economies and largely depend on the emission reduction effort included in the NDCs. However, two G20 economies have submitted new targets that will lead to an increase in emissions of about 0.3 GtCO₂eq, compared to their previous NDCs. The updated NDCs of non-G20 economies contain further net reductions. We conclude that countries should strongly increase the ambition levels of their updated NDC submissions to keep the climate goals of the Paris Agreement within reach.

Supplementary information: The online version contains supplementary material available at 10.1007/s11027-022-10008-7.

Keywords: Climate change mitigation; Climate policy; Greenhouse gas emissions scenario; Integrated assessment models; NDC; Paris Agreement.

Fig. 1

The contribution of the updated NDC targets of countries on total additional global emission reduction (as indicated in blue column) based on the full implementation of the unconditional NDC targets (upper figure) and conditional NDC targets (lower figure), compared to the previous NDCs. The green columns indicate additional reductions from individual G20 economies, the non-G20 countries as a group with their stronger NDC targets (compared to their previous NDCs), and the red columns indicate the increase in emissions from G20 economies with their weaker NDC targets. The uncertainty ranges represent the reductions relative to the current policies scenarios (such as for the EU-27), or other uncertainties related to the range in reduction targets (such as South Africa), or the uncertainties in the base-year emissions (Brazil). Some G20 economies are not shown as they have submitted the same reduction targets in their updated NDC or have not yet submitted an updated NDC (see Table 1)

Fig. 2

Projected absolute emission reductions relative to the current policies scenario in 2030 by the G20 countries and the non-G20 countries as a group based on their NDCs. For countries with a reduction target range, projected reductions were based on the average of the range

Fig. 3

Impact of the implementation of the NDCs and current policies on greenhouse gas emission projections and on narrowing the emission gap in 2030

Fig. 4

Kyoto greenhouse gas emissions by 2030 for selected regions, including the EU-27 and the UK as one region (EU28), projected by models for cost-optimal 1.5 °C and 2 °C scenarios, compared to unconditional NDCs and current policies. Total emissions are shown in comparison to 2015 levels (%, with positive numbers indicating an increase in emissions). Dots represent the emission reductions needed to meet the same world per capita emission levels for 2 °C and 1.5 °C. Solid NDC bars show the central estimate in this study, and error bars present the range. There are three types of NDC ranges: the range for the reduction target mentioned in the NDCs themselves (‘Target’; Canada, USA), the range resulting from unconditional targets, and the range resulting from various model studies (‘Model Studies NDC’; India, China)

Fig. 5

Impact of the emissions and their removal from the LULUCF sector by 2030. A negative estimate, here, reflects an enhancement of GHG commitments for the LULUCF sector within the updated NDCs, as compared to the previous NDCs. Others here shows the combined contribution for Mongolia, Papua New Guinea, Suriname, Chile, Cuba, Mexico, Macedonia, Niger, Ghana and Comoros