The strategic management models of the late Igor Ansoff predict that the effectiveness of organizational strategies and management capabilities depends in part on the turbulence of the business environment in which the organization operates. Ansoff defined five levels of turbulence, and identified the characteristics of strategic aggressiveness and management capabilities that are most effective for a given level of turbulence. Greg Lorton adapted Ansoff's corporate models to environmental management systems within organizations, surveying 78 businesses and government organizations in California. He found that these models continue to be effective when applied to environmental management systems. He further studied the elements of environmental management strategies and how they relate to environmental strategic aggressiveness, management capabilities, and performance on environmental issues. While proactive environmental management systems generally lead to improved environmental performance, in some cases more conservative systems can also be effective.