Even with strong mitigation, some degree of climate change is now unavoidable because past emissions have already committed the planet to further warming and sea-level rise. Adaptation is the response to this reality: adjusting systems, behaviors, and infrastructure to reduce harm from the impacts that cannot be prevented. Mitigation and adaptation are complementary, not alternatives. Mitigation tackles the causes to limit how bad things get, while adaptation tackles the consequences to help people and ecosystems cope with the change that is already underway. Relying on only one is inadequate; a world that mitigates but does not adapt still suffers avoidable losses, and a world that adapts but does not mitigate faces impacts that eventually outpace any possible adjustment.
Adaptation takes