Chambers was born in Haliburton, Ontario, Canada. Before joining CMS, he was the Senior Legal Officer and Chief of the Law and Governance Branch of UNEP. An important part of UNEP responsible for developing international environmental law, providing capacity building and technical guidance on governance and legal issues to developing countries. Chambers has been a frequent contributor to international environmental governance reform and processes either through his exploration of new concepts of law and governance through his many writings or through offering alternative options for developing international environmental reforms. In 2010 Chambers led the International Environmental Governance Strategic Team working directly for the then Executive Director Achim Steiner. The team led the secretariat for the Nairobi-Helsinki Ministerial Consultative Process International Environment Governance which made key recommendations on strengthening UNEP. In 2012 at Rio+20 Chambers continued to lead the team and engage governments resulting in a final outcome in The Future We Want that was a major step forward for upgrading and strengthening UNEP. This included transforming UNEP's Governing Council into a universal body called the United Nations Environmental Assembly, increasing its regular budget, and strengthening UNEP's institutional base in the United Nations.