Environmental crime is a significant and increasingly lucrative business. Environmental crime is estimated to be worth approximately 91–258 billion USD annually (2016) and is rising 5-7% annually, which is 2–3 times the rate of the global economy. Illegal international trade in environmentally-sensitive commodities such as ozone depleting substances, toxic chemicals, hazardous wastes, and endangered species is an international problem with serious consequences. It threatens human health and the environment; contributes to species loss; results in revenue loss for governments; and undermines the success of international environmental agreements by infringing upon agreed rules and procedures.

Customs and border control officers constitute the front line of every country's defence against transboundary illegal trade. They are the first link in the compliance and enforcement chain, and without adequate capacity to prevent or detect illegal trade, the rest of the chain will be considerably less effective. Building the capacity of these officers is vital. Training is a key component of capacity building but can be time-consuming and expensive when delivered separately for the wide range of issues customs officers must cover. An effective solution is coordinated training – and this is where Green Customs comes in.

UNEP’s Governing Council expressed concern over the increasing environmental damage caused by illegal traffic in endangered species and dangerous and harmful substances and products. It also recognised that continuous efforts must be undertaken by all countries and relevant organisations and agencies concerned with ensuring compliance and enforcement of relevant international agreements. The Green Customs Initiative is a partnership actively addressing these concerns. (Council Decision 21/27 on Compliance with and enforcement of multilateral environment agreements, February 2001).