Resumen del autor, extraído del trabajo. Recent legislation and guidelines in many countries require petroleum companies to address potential cumulative environmental effects in project planning and environmental reviews. Cumulative environmental effects are changes to the environment that are caused by projects or activities in combination with other past, present, and future projects or activities. Consideration of cumulative environmental effects is at the leading edge of impact assessment technology and neither the petroleum industry, regulators, nor public stakeholders are clear about how cumulative environmental effects should be considered. Legal and technical uncertainty increases potential costs and risks for project proponents. This poster describes a cumulative effects assessment approach successfully applied and defended in a recent international pipeline project in western North America. With this approach, assessment of cumulative environmental effects was conducted for ‘representative areas’ comprised of one or more 1:50,000 scale map sheets. These areas were selected to include multiple project facilities or activities and to reflect biophysical conditions and administrative boundaries. Impact analyses conducted for these representative areas considered indices of landscape conditions, physical variables, and indicator species or groups.