Environmental crime - from illegal logging and gold mining to wildlife trafficking and toxic waste - has long been sidelined in climate diplomacy. At COP28, civil society and agencies such as the FACT coalition, Igarape Institute, Interpol and the UN Office for Drugs and Crime pushed environmental crime onto the agenda. Notwithstanding incremental diplomatic progress, formal recognition of environmental crime in the UNFCCC remains patchy. Environmental crime still sits outside the main negotiating tracks, despite its corrosive effects on the rule of law, investment, and climate action. Tackling environmental crime is not just about safeguarding forests: it is about preserving the credibility of the climate regime itself.