What is the Issue?

An Environmental Management System (EMS) is a problem identification and problem solving tool that provides companies with a method to systematically manage their environmental activities, products and services and helps to achieve their environmental obligations and performance goals. ISO, the International Standards Organization, defines an EMS as "the part of the overall management system that includes organizational structure, planning activities, responsibilities, practices, procedures, processes and resources for developing, implementing, achieving, reviewing and maintaining the environmental policy."
ISO has developed a series of voluntary standards and guidelines in the field of environmental management, which are collectively known as the EN ISO 14000 series. Within this series, "EN ISO 14001:1996 environmental management systems — specifications with guidance for use" is the only certifiable standard, the remainder being supportive guidelines.
EMAS is the EU's Eco-Management and Audit Scheme. It has legal status within Member States, while being a voluntary instrument for companies.