Global Environmental Outlook: The GEO-4 Report

Abstract

Published twenty years after the Brundtland Report, this article presents the executive summary of UNEP's Fourth Global Environment Outlook (GEO-4), prepared with the participation of 390 international experts. The text summarizes the report's ten chapters, addressing the state of the atmosphere, land, water, and biodiversity, along with differentiated regional outlooks for the world's seven GEO regions. The document highlights a one-third increase in global CO2 emissions since 1987, humanity's ecological footprint of 21.9 hectares per person against a global biocapacity of 15.7 hectares per capita, and presents four scenarios projected to 2050, concluding that only a "Sustainability First" pathway would stabilize greenhouse gas concentrations.