Climate justice is the framing of climate change as a rights and equity issue, not merely an environmental one: the communities least responsible for historical greenhouse gas emissions are disproportionately exposed to its worst impacts, raising questions of intergenerational and international fairness.

Social justice is the fair distribution of opportunities, resources, and recognition across a society, with special attention to disadvantaged and marginalised groups.

Strong sustainability holds that certain forms of natural capital are critical and cannot be substituted by anything else. Their loss makes the whole system unsustainable, no matter how much else is gained.

Sustainability refers to the ability to meet the needs of the present without compromising the ability of future generations to meet their own needs.

Brundtland Commission defines it as: "Development that meets the needs of the present without compromising the ability of future generations to meet their own needs." Other definitions emphasize the need to balance economic growth, social well-being, and environmental protection.

Weak sustainability holds that natural capital can be substituted by human-made capital. So long as total capital is maintained or grows, the loss of any single natural resource is acceptable.