Cities are increasingly being recognised as key arenas for governing and tackling global environmental challenges, including the interlinked climate and biodiversity crises. Yet urban areas have historically exacerbated these issues. Cities are estimated to account for 60-75% of global GHG emissions, when consumption of goods and services produced outside of cities is taken into account, while urban expansion and densification are responsible for degrading, fragmenting, or destroying remaining natural areas. According to the European Environmental Agency’s recently published State of Nature report, the majority of Europe’s biodiversity continues to decline at an alarming rate and urban sprawl is amongst the greatest threats.