Earth is the only planet in the universe known to support life. The stable climate of the Holocene epoch enabled the emergence and evolution of human civilisation. Unfortunately, because of human activities, carbon dioxide concentrations in the atmosphere are at their highest level in millions of years; one million species are at risk of extinction; nine million people die prematurely every year from pollution; and there has been a surge of emerging infectious dis-eases of zoonotic origin, exemplified by the catastrophic COVID-19 pandemic. As the interlocking crises of climate disruption, biodi-versity collapse, pervasive pollution and pandemics deepen, it is increasingly apparent that the fundamental legal rules governing human societies need to be rewritten. As world-leading scientists with the Intergovernmental Panel on Climate Change, Intergov-ernmental Science-Policy Platform on Biodiversity and Ecosystem Services and World Health Organization have concluded, human-ity must make rapid, systemic and transformative changes in order to secure a sustainable future.