The main objective of Elsevier's Dictionary of Environment is to assist those involved in environmental activities in their attempt to make the world cleaner and to sustain its natural resources for future generations. It will help with the production of documentation for meetings and conferences as well as for drafting papers for training, information and communication purposes. Environmental concerns are important items on the political and economic agendas of most countries, whether developed or developing. In a world conscious of its environmental problems, studies in this domain have become an established discipline. Every new branch of science needs to define relevant terms to be used through the medium of language. The subject of environment is global because it touches everyone. Individuals, specialists or institutions concerned with the health of our planet need to mean the same thing when communicating with each other, notwithstanding language differences. The compilation of a multilingual dictionary on environment is not easy. The inclusion or omission of certain terms is an important question. However, the choice of terms, in this text, is based on two assumptions: (1) the most commonly used terms, (2) their translatability into other languages without losing their intended meaning. Consideration of regional differences of the same languages has been taken into account. This dictionary contains terms covering the following fields and subfields: air pollution, biological diversity, biomass energy, biosafety, biotechnology, climate change, coastal environment, deforestation, desertification, endangered species, energy conservation, environmental economics, environmental impact assessment, forest conservation, freshwater pollution, global warming, greenhouse gases, human settlements, living marine resources, marine environment, mountain ecosystems, ozone layer, resources management, soil degradation, sustainable development, tropical ecosystem, wetland ecosystem. The layout of this dictionary is such that each language included may be used as a target as well as a source language.