If one were to consider the term ‘legitimacy’ literally, one would recognise an inherently legal concept.1 But the law is always and already made valid through the culture in which it works. Shakespeare’s King Lear character Edmund voices the conflict between the cultural recognition of him, born ‘in the lusty stealth of nature’, and his brother ‘legitimate Edgar’ in whom the father finds little resemblance or representation of himself. Where do cultures find resemblance and representation in the phenomenon of climate change? The answer, it would seem, is an alchemy of science and law, with chemical signatures from other disciplines as well. So why do some people seem to acquiesce in climate change law and others do not? If we ever thought that once we agreed on the anthropogenic cause of the problem, we could solve it, we were wrong. Mitigating climate change and adapting to its effects have proven to be problems in need of more than science-based rationality or legal rules for solving. It is an ethical problem between differing cultures with differing values, whatever the science or law may say. And the same rational law based upon the same rational science will not be effective without a shared cultural identification in the problem and solution.