GEO-4, the latest in UNEP’s series of flagship reports, assesses the current state of the global atmosphere, land, water and biodiversity, describes the changes since 1987, and identifies priorities for action. GEO-4 is the most comprehensive UN report on the environment, prepared by about 390 experts and reviewed by more than 1,000 others across the world.

While the world has made progress in tackling some relatively straightforward problems, the harder-to-manage issues remain “persistent” problems. Failure to address these persistent problems, UNEP says, may undo all the achievements so far on the simpler issues, and may threaten humanity’s survival. But it insists: “The objective is not to present a dark and gloomy scenario, but an urgent call for action.”

The international community’s response to the Brundtland Commission has in some cases been courageous and inspiring. But all too often it has been slow and at a pace and scale that fails to respond to or recognize the magnitude of the challenges facing the people and the environment of the planet.

—Achim Steiner, UN Under-Secretary General and UNEP Executive Director

Ecological footprint and biocapacity by region. Click to enlarge.

On climate change the report says the threat is now so urgent that large cuts in greenhouse gases by mid-century are needed. GEO-4 also warns that we are living far beyond our means. The human population is now so large that “the amount of resources needed to sustain it exceeds what is available... humanity’s footprint [its environmental demand] is 21.9 hectares per person while the Earth’s biological capacity is, on average, only 15.7 ha/person...”

GEO-4 recalls the Brundtland Commission's statement that the world does not face separate crises—the environmental crisis, development crisis, and energy crisis are all one. This crisis includes not just climate change, extinction rates and hunger, but other problems driven by growing human numbers, the rising consumption of the rich and the desperation of the poor.

Critical problems highlighted in GEO-4 include:

• Atmosphere. The report calls climate change a global priority, demanding political will and leadership. The report, however, finds “a remarkable lack of urgency” and a “woefully inadequate” global response. “Fundamental changes in social and economic structures, including lifestyle changes, are crucial if rapid progress is to be achieved.”

  Adaptation to climate change is necessary even if major mitigation measures are rapidly implemented. The array of potential adaptive responses available to human societies is very large, ranging from purely technological (such as sea defences), through behavioral (such as altered food and recreational choices) to managerial (such as modified farm practices), and policy (such as planning regulations).

  GEO-4 also highlights ongoing issues with air pollution. More than 2 million people are estimated to die prematurely each year due to indoor and outdoor air pollution.

• Land. Unsustainable land and water use, and the impacts of climate change are driving land degradation, including soil erosion, nutrient depletion, water scarcity, salinity, chemical contamination and disruption of biological cycles.

  The cumulative effects of these changes threaten food security, biodiversity, and carbon fixation and storage.

• Water. Irrigation already takes about 70% of available water, yet meeting the Millennium Development Goal on hunger will mean doubling food production by 2050. Fresh water is declining: by 2025, water use is predicted to have risen by 50% in developing countries and by 18% in the developed world. Water quality is declining, polluted by microbial pathogens and excessive nutrients. Globally, contaminated water remains the greatest single cause of human disease and death.

• Fish. Consumption more than tripled from 1961 to 2001. Catches have stagnated or slowly declined since the 1980s. Subsidies have created excess fishing capacity, estimated at 250% more than is needed to catch the oceans' sustainable production.

• Biodiversity. Current biodiversity changes are the fastest in human history. Species are becoming extinct a hundred times faster than the rate shown in the fossil record. The Congo Basin’s bushmeat trade is thought to be six times the sustainable rate. Of the major vertebrate groups that have been assessed comprehensively, more than 30% of amphibians, 23% of mammals and 12% of birds are threatened.

  The intrusion of invasive alien species is also a growing problem. The comb jellyfish, accidentally introduced in 1982 by US ships, has taken over the entire marine ecosystem of the Black Sea, and had destroyed 26 commercial fisheries by 1992.

• Regional Pressures. This is the first GEO report in which all seven of the world’s regions emphasize the potential impacts of climate change. In Africa, land degradation and even desertification are threats; per capita food production has declined by 12% since 1981. Unfair agricultural subsidies in developed regions continue to hinder progress towards increasing yields. Priorities for Asia and the Pacific include urban air quality, fresh water stress, degraded ecosystems, agricultural land use and increased waste. Drinking water provision has made remarkable progress in the last decade, but the illegal traffic in electronic and hazardous waste is a new challenge. Europe’s rising incomes and growing numbers of households are leading to unsustainable production and consumption, higher energy use, poor urban air quality, and transport problems. The region’s other priorities are biodiversity loss, land-use change and freshwater stresses.

  Latin America and the Caribbean face urban growth, biodiversity threats, coastal damage and marine pollution, and vulnerability to climate change. But protected areas now cover about 12% of the land, and annual deforestation rates in the Amazon are falling.

  North America is struggling to address climate change, to which energy use, urban sprawl and freshwater stresses are all linked. Energy efficiency gains have been countered by the use of larger vehicles, low fuel economy standards, and increases in car numbers and distances travelled.

  Passenger car use in the Asia region. Click to enlarge.

  In Asia and the Pacific, environmental change is driven by rapid population growth, changing consumption patterns accompanying higher incomes, and burgeoning industrial and urban development. A number of factors are contributing to an increase in urban air pollution, including an increase of 2.5 times in the use of passenger cars over the past two decades. (See chart at right.)

  For West Asia the priorities are freshwater stresses, degradation of land, coasts and marine ecosystems, urban management, and peace and security. Water-borne diseases and the sharing of international water resources are also concerns.

  The Polar Regions are already feeling the impacts of climate change. The food security and health of indigenous peoples are at risk from increasing mercury and persistent organic pollutants in the environment. The ozone layer is expected to take another half-century to recover.

The Future. GEO-4 acknowledges that technology can help to reduce vulnerability to environmental stresses, but says there is sometimes a need to correct the technology-centred development paradigm. It explores how current trends may unfold by 2050 in four scenarios:

• Markets First: the private sector, with active government support, pursues maximum economic growth as the best path to improve the environment and human well-being for all.

• Policy First: the government sector, with active private- and civic-sector support, implements strong policies intended to improve the environment and human well-being, while still emphasizing economic development.

• Security First: the government sector and the private sector vie for control in efforts to improve, or at least maintain, human well-being for mainly the rich and powerful in society.

• Sustainability First: the civic, government and private sectors work collaboratively to improve the environment and human well-being for all, with a strong emphasis on equity.

None of the scenarios describes a utopia. Even though some improvements are seen and there is an indication of a slowing of the rate of change in some aspects of global environmental change, some problems remain persistent in all of the scenarios. In particular, climate change and the loss of biodiversity will continue to present significant challenges, and may eventually pose the danger of crossing critical thresholds in the Earth system. Similarly, with respect to human well-being, significant advances are achievable, particularly in Sustainability First, but even these will take time, and significant inequities will remain by the end of the scenario horizon.

Furthermore, there are costs and risks in each scenario. These are perhaps most evident in Security First, where a narrow definition of security for some is likely to result in increasing vulnerabilities for all. In Markets First, both the environment and society move the fastest towards if not beyond tipping points, where sudden, abrupt, accelerating and irreversible changes may occur. This is of particular concern given the uncertainties in the resilience of environmental and social systems.

Under Policy First and Sustainability First, society will achieve a higher material standard of living and greater protection of the environment, but at a significant cost. Indeed, there are particular costs and risks in terms of the actions and approaches taken to address the issues of environment and human well-being. The social and economic costs of these actions may significantly exceed what has been previously assumed, and the lower economic growth seen in the currently well-off regions in Sustainability First may not prove to be acceptable.

The time required to implement the actions might increase, due to the greater level of bureaucracy foreseen in Policy First and the increased level of coordination in Sustainability First. Finally, trade-offs may imply that the pursuit of a balanced approach in Sustainability First could work against greater progress on any specific target.

Still, to the extent that the scenarios reflect our understanding of the Earth system and environmental governance, they indicate that some approaches are more likely to be effective than others. Specifically, it is important to recognize the trade-offs, synergies and opportunities that exist in addressing the challenges of achieving environmental, development and human well-being goals.

...Furthermore, the scenarios point to the need to act quickly. Our common future depends on our actions today, not tomorrow or some time in the future.

Resources

• Global Environment Outlook 4