Assessments of the societal transformations required to achieve the Paris Agreement’s objectives28 offer some insight into the advantages and trade-offs of the sectoral mitigation actions found most commonly throughout the NDCs (see Supplementary Information for a summary of these actions). The potential for various types of infrastructure to influence sustainable development outcomes is well-documented19,29, as are the extensive SDG impacts of measures related to land use and restoration30,31. Not surprisingly, the development of renewable energy generation capacity has been identified as the most feasible direction to meet climate mitigation objectives32, although the early implementation of stringent demand reductions and efficiencies are also predicted to increase flexibility to meet emissions targets in the long run33. While proportional contributions from the transport sector have been considered difficult to achieve34, a nuanced approach to identifying effective emissions reductions measures and policies can realise greater mitigation potential within the sector35. In the waste sector, where the large role of methane in global warming is recognised, a range of potential actions can come together as part of an effective management and mitigation strategy36. However, the efficacy of such a strategy has been shown to be context-specific, based on factors such as the characteristics of the waste stream37.
Among the land use sectors, large-scale afforestation and reforestation are considered key components of carbon dioxide removal efforts38. In agriculture, policy options through which to increase mitigation ambition remain comparatively diverse39, and efforts to integrate non-uniform mitigation targets into national policy frameworks have proven challenging40. In addition to highlighting potential areas of focus for policymakers designing mitigation strategies, trade-offs between certain types of policies and development outcomes in key areas such as food security and energy access have been identified41.
In Figure 2, we depict the objective of coordinated mitigation action between GHG emissions reductions and sustainable development for countries at different starting points in both of these measures, based on the IPCC concept of a ‘sustainable development corridor’. The latter is represented by overall national progress toward all 169 social, economic, and environmental targets, of which each country will have achievement gaps according to their context and characteristics, which can be targeted by NDC mitigation actions.
We demonstrate this concept in practice for four indicators used in the Sustainable Development Report10 to represent SDG target performance. We identify where unconditional sectoral actions included in NDCs can directly enhance target performance, and its magnitude if implemented as committed, focusing here on the impact of specific NDC actions on relevant indicators for four SDG targets: renewable energy (7.2); clean cooking (7.1); municipal solid waste generation (12.5); and deforestation (15.2). While desired targets are generally defined at the national level42, we use the long-term objective defined by the Sustainable Development Report10 for each indicator to improve comparability, representing ‘full achievement’ of the target: renewable energy (55%); clean cooking (100%), municipal solid waste per capita (0.1 kg/day); and permanent deforestation (0%). Calculating changes in SDG target outcomes and emissions across these four indicators (see Methods for details), we observe varying levels of sustainable development benefit from current NDC commitments, as depicted in Figure 3.
Renewable energy commitments – the most commonly reported mitigation action in the NDCs – show high potential both to improve energy security as measured by SDG 7 and to achieve mitigation targets, although only 36% of countries commit to reaching a long-term target of at least 55% renewable share. While baseline performance varies by income group, countries classed as lower-middle income (LMIC) report the most quantified actions (59% of countries), followed by upper-middle income (UMIC) (56%), and low-income (LIC) (50%) countries, with high-income countries (HIC) at only 22%. In terms of magnitude, UMIC average around 33% improvement on baseline levels, followed by LIC (32%), LMIC (30%), and HIC (23%).
In contrast, access to efficient cookstoves is strongly correlated to income group, with many low-income countries scoring poorly as a baseline. Most targets related to the implementation of efficient cookstoves therefore focus on these low- and lower-middle income countries (29 and 22% of each group respectively), with large gains in access expected as a consequence of these NDCs - an average of 49% improvements on baseline levels for LIC and 11% for LMIC. Due to the reliance on wood and biomass for cooking in many of these countries, emissions reductions are strongly evident as a share of the overall energy emissions budget. Only 31% of countries actually commit to the long-term objective of 100% access, although many middle- and high-income countries have a high baseline of >95% access.
Despite improvements in recycling and compost rates, higher income countries tend to score more poorly on indicators of municipal solid waste generation given their higher consumption and waste generation rates. Fewer countries report quantified waste targets, with the majority found among LMIC (24% of the income group), however larger improvements on baseline performance are pledged in LIC (40%), and UMIC (24%). Overall, only 3% of countries are in position to achieve the 0.1 kg/capita/day long-term objective, mostly through ambitious landfill and recycling initiatives in a handful of low- and lower-middle income countries. These NDC commitments contribute to limited overall mitigation reductions, although given different waste stream content in each country (e.g. recyclable and organic material having been sorted to a greater extent in HIC), the emissions reduction potential of a percentage reduction may vary.
Afforestation and reforestation targets suggest moderate to large sectoral mitigation potential owing to increased carbon uptake, with 25% of countries committing to forestation programmes that have potential to counteract deforestation trends. However, countries that lack quantified commitments show a negative trajectory as continued deforestation leads to increased emissions in the sector. While high income countries generally score well as a deforestation baseline, the limited areas of existing or remaining forested land in many of these regions mean that reforestation potential is often greater. On average, LMICs show the most commitment to improving on current deforestation rates through their NDC actions (28% of the income group), while these numbers are only 14%, 5%, and 3% for LIC, UMIC, and HIC, respectively.