The Global Environment Outlook: environment for development (GEO-4) report is published in what may prove to be a remarkable year – a year when humanity faced up to the scale and pace of environmental degradation with a new sense of realism and honesty matched by firm, decisive and above all, imaginative action. It highlights the unprecedented environmental changes we face today and which we have to address together. These changes include climate change, land degradation, collapse of fisheries, biodiversity loss, and emergence of diseases and pests, among others. As society, we have the responsibility to tackle these and the development challenges we face. The trigger propelling countries and communities towards a rediscovery of collective responsibility is the most overarching challenge of this generation: climate change.