The challenges of combatting climate change are unprecedented and now very urgent. Current approaches are not working fast enough. This paper, and this journal issue, conceive of the challenge as one of non-marginal structural and institutional change. Several different conceptual frameworks and pluralist theories are considered, emanating from complexity theory, economics, natural sciences, political economy, and strategy. These are deployed to identify potential accelerators, including synergies between climate action and other key political issues, and beneficial non-linear dynamics such as shifts in consumer preferences and technology learning curves. The delays in action also mean that removing carbon dioxide from the atmosphere is now necessary, and even unconventional geoengineering approaches may need to be considered. A pluralist and practical approach to climate action, accounting for different institutional and social contexts across countries, is argued to be required to accelerate action.