"Adaptation" refers to the adjustments that societies or ecosystems make to limit the negative effects of climate change or to take advantage of opportunities provided by a changing climate. Adaptation can range from a farmer planting more drought-resistant crops to a coastal community evaluating how best to protect its infrastructure from rising sea level.

Climate change is already impacting societies and ecosystems around the world, and many impacts are expected to increase as global temperatures continue to rise. While reducing greenhouse gas emissions is required to avoid the worst impacts of climate change, a certain amount of global warming is inevitable, due to the long-lasting nature of greenhouse gases already in the atmosphere, and to heat already stored in the oceans. Adapting to the changes that are already underway, and preparing for future climate change, can help reduce the risks societies will face from climate change.