On 5 June 1972, in the Swedish capital, they began to build their response, in the form of the United Nations Conference on the Human Environment - the first UN summit on the environment, and the event that really put the issue on the global political agenda.

BBC: Stockholm: Birth of the green generation

Environment Commissioner Janez Potocnik said that legislation on its own would not solve the issue and called for more global action.

BBC: MEPs back ban on sale of illegal timber