This collection of studies is intended to help trade negotiators navigate through the international discussion over liberalising trade in environmental goods and services by exploring in greater depth three categories of environmental goods: environmentally preferable products, renewable-energy products and energy-efficient products. Its three chapters consider the scope and definition of each product category, examine tariff and non-tariff barriers to trade, and explain the environmental effects of liberalising such goods.  This book follows a previous volume, Trade that Benefits the Environment and Development: Opening Markets for Environmental Goods and Services, published in 2005,