Ending the use of unabated coal power is a key climate change mitigation measure. However, we do not know how fast it is feasible to phase-out coal on the global scale. Historical experience of individual countries indicates feasible coal phase-out rates, but can these be upscaled to the global level and accelerated by deliberate action? To answer this question, we analyze 72 national coal power phase-out pledges and show that these pledges have diffused to more challenging socio-economic contexts and now cover 17% of the global coal power fleet but their impact on emissions (up to 4.8 Gt CO2 avoided by 2050) remains small compared to what is needed for achieving Paris climate targets. We also show that the ambition of pledges is similar across countries and broadly in line with faster historical precedents of coal power decline. While some pledges strengthen over time, up to 10% have been weakened by the energy crisis caused by the Russo-Ukrainian war. We construct scenarios of coal power decline based on empirically-grounded assumptions about future diffusion and ambition of coal phase-out pledges. We show that under these assumptions unabated power generation from coal in 2022-2050 would range from generation equivalent to the median in 2°C-consistent IPCC AR6 pathways and three-quarters of 2.5°C-consistent pathways. More ambitious coal phase-out scenarios require much stronger effort in Asia than in OECD countries which raises fairness and equity concerns. The majority of the 1.5°C- and 2°C-consistent IPCC pathways envision even more unequal distribution of effort and faster coal power decline in India and China than has ever been historically observed in individual countries or pledged by climate leaders.

The pursuit of civil nuclear power, frequently justified in the name of national energy security, paradoxically entangles most states in long-term interdependencies with the few countries capable of supplying nuclear technologies. These interdependencies are insufficiently documented and poorly understood. This article presents and analyzes a new dataset of nuclear cooperation agreements signed or announced between 2000 and 2015. We find that Russia and the US dominate international technological nuclear cooperation, with the US' dominance particularly prominent in safety and security and Russia's-in nuclear power plant construction, reactor and fuel supply, decommissioning and waste. When it comes to these technologies, Russia is the supplier in approximately half of all agreements; France, the US, China, Korea, and Japan together account for another 40%. All in all, six countries are suppliers in over 90% of all international nuclear agreements, a far higher supplier concentration than in oil and gas markets. These results show that the global future of nuclear power depends as much on international cooperation as on national motivations and capacities. Effective policies and institutions supporting the safe use of nuclear power should therefore be directed at managing its international as well as national aspects.