D. V. van Vuuren

The role of negative CO2 emmissions for reaching 3 C-insights form integrated assessment modelling

Sector-detailed urban greenhouse gas emission futures derived from the ScenarioMIP-CMIP7 ensemble

Emission reductions required to meet the goals of the Paris Agreement have been extensively analyzed using integrated assessment modeling scenarios. However, the contribution of urban areas in aggregate, globally, by region and by city type, remains underexplored. Here, we develop a spatially explicit framework to downscale global emissions pathways to urban areas, differentiated by region and city type. Ambitious climate change mitigation could deliver 21 GtCO₂e of greenhouse gas (GHG) emission reductions in urban areas by 2050 relative to a continuation of current policies and trends, primarily by transitioning away from fossil fuels in electricity and heat supply, deep decarbonization of industry, and mitigation in the transport and buildings sectors. Mitigation potential is concentrated in established and rapidly growing cities, reflecting their high current per-capita emission levels. Asian regions with high urbanization levels dominate global urban emissions and reduction potentials. The findings underscore the central role of cities in achieving global climate targets and highlight the importance of differentiated mitigation strategies across regions and city types.

Emission pathways consitent with 2C global temperature limit

Diversity of circular economies from Global South evidence

The circular economy (CE) is widely viewed as a key global lever for sustainable resource use. However, CE conceptualizations have focused mostly on high resource use in the Global North, largely neglecting the drivers, solutions and enablers of circularity in the socio-economic contexts of the Global South. Here, based on a systematic review of 183 peer-reviewed articles, we assess how CE manifests in the Global South. We find circular solutions to be considerably more bottom-up, centring around community-level and often informal practices rather than the top-down, policy and industrially driven activities that dominate the Global North-informed CE literature. CE motivations similarly differ, being primarily rooted in socio-economic needs and cultural practices rather than environmental concerns. Finally, CE enablers are often based on socially and technically adaptive approaches rather than technological innovation. These differences reveal that inclusive circular pathways for sustainable development depend strongly on context, suggesting the need for more flexible and empirically grounded CE concepts.