Decisions involving environmental aspects are complex. The underlying environmental processes are tackled by teams that are invariably multidisciplinary in nature and involve sundry specialists: earth, physical, chemical, geochemical, biological, benthic, and ecological sciences. Many decisions, such as water resources allocation, irrigation and agricultural practices, toxic waste management, industrial effluent regulation, acid rain mitigation, and climate change accommodation are interrelated. The solution or mitigation of one problem usually affects another. In addition, the constraints to these solutions are legion: economic considerations for remedial costs, social values of clean water and air, political and public opinions on biodiversity, and so on. Environmental decision makers and policy advisors need to consider all these complex factors in their decision‐making and policy‐building processes. The purpose of this article is to discuss the tools that an environmental manager may need to support decision‐making processes. With the advent of information technology, this article focuses on the possible use of computer systems to provide the support. Their design, implementation, advantages, and disadvantages are discussed and examples of applications and future directions are given. These systems are called
environmental decision support systems
.