This UN Environment Programme report "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 collectiveresponsibility is the most overarching challenge of this generation: climate change.
Humanity's capacity to order its affairs in a stable and sustainable way is likely to prove impossible if greenhouse gases are allowed to rise unchecked. Attempts to meet the Millennium Development Goals relating to poverty, water and other fundamental issues may also fail without swift and sustained action towards de-carbonizing economies.
The difference between this GEO and the third report, which was released in 2002, is that claims and counter claims over climate change are in many ways over. The Intergovernmental Panel on Climate Change (IPCC) has put a full stop behind the science of whether human actions are impacting the atmosphere and clarified the likely impacts - impacts not in a far away future but within the lifetime of our generation.
The challenge now is not whether climate change is happening or whether it should be addressed. The challenge now is to bring over 190 nations together in common cause. The prize is not just a reduction in emissions of greenhouse gases, it is a comprehensive re-engagement with core objectives and principles of sustainable development. For climate change, by its very nature cannot be compartmentalized into one ministerial portfolio, a single-line entry in corporate business plans or a sole area of NGO activism. Climate change, while firmly an environmental issue is also an environmental threat that impacts on every facet of government and public life - from finance and planning to agriculture, health, employment and transport. If both sides of the climate coin can be addressed - emission reductions and adaptation - then perhaps many of the other sustainability challenges can also be addressed comprehensively, cohesively and with a long-term lens rather than in the segmented, piecemeal and short-sighted ways of the past. GEO-4 underlines the choices available to policymakers across the range of environmental, social and economic challenges - both known and emerging. It underlines not only the enormous, trillion-dollar value of the Earth's ecosystems and the goods-and-services they provide, but also
underscores the central role the environment has for development and human well-being."