Sustainability is a social goal for people to co-exist on Earth over a long period of time. Definitions of this term are disputed and have varied with literature, context, and time.[2][1] Sustainability usually has three dimensions (or pillars): environmental, economic, and social.[1] Many definitions emphasize the environmental dimension.[3][4] This can include addressing key environmental problems, including climate change and biodiversity loss. The idea of sustainability can guide decisions at the global, national, organizational, and individual levels.[5] A related concept is that of sustainable development, and the terms are often used to mean the same thing.[6] UNESCO distinguishes the two like this: "Sustainability is often thought of as a long-term goal (i.e. a more sustainable world), while sustainable development refers to the many processes and pathways to achieve it."[7]