To talk about climate change needs ideas of systems and chaos, but also the conceptual vocabularies of physics, law, socialism, capitalism, economics, religion, anthropology and ecology. Ecology offers the most useful reference language, but there are similarities between ecological systems that depend on webs of life, biodiversity and functional integrity, and human social systems that depend upon forums, culture and resource-tenure security. Climate change is most clearly directional and its effects most predictable at the ‘macro’ (continental and global) level, and its effects are most chaotic and least predictable at the ‘micro’ (local and landscape) level. People depend on ecological conditions at the micro level, where strong ecological and social systems are better able than weak ones to withstand any impact. Thus, preserving and restoring the strength of systems at the micro level is a key to adaptation, and algorithmic principles for this depend on understanding and sharing knowledge, envisioning the future, choosing good leaders and leaving no one behind. The latter requires collective security based on small groups in which people know each other well enough to identify and protect the vulnerable.