OECD's comprehensive 2004 report on Canada's environmental policies and programmes systematically examines policy related to air, water, and nature/biodiversity as well as the interface between environmental policy and economic policy, social policy, and specific sectors.  It finds that while Canada has made satisfactory progress since 1985, there are still significant challenges, and the report makes specific recommendations for more use of economic instruments and use of the polluter and user pays principles, rationalising water governance, strengthening nature protection, reducing energy intensity, implementing climate change policies, reviewing environmentally related taxes, and implementing marine and aid commitments.