- Climate change, the rate of extinction of species, and the challenge of feeding a growing population put humanity at risk, October 25. GEO-4 is the most comprehensive United Nations report on the environment, prepared by about 390 experts and reviewed by more than 1 000 others across the world. 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.  topic
The Global Environment Outlook (GEO) is UNEP 's flagship assessment process and report series. The fourth report in the series provides an overview of the global and regional environmental, social and economic state-and-trends over the past two decades. It highlights the interlinkages, challenges and opportunities which the environment provides for development and human wellbeing.
It salutes the world's progress in tackling some relatively straightforward problems, with the environment now much closer to mainstream politics everywhere. But despite these advances, there remain the harder-to-manage issues, the "persistent" problems. Here, GEO-4 says: "There are no major issues raised in Our Common Future for which the foreseeable trends are favourable."
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."
Selected facts from the report Edit
There is now "visible and unequivocal" evidence of the impacts of climate change, and consensus that human activities have been decisive in this change: global average temperatures have risen by about 0.7 °C since 1906. A best estimate for this century's rise is expected to be at least a further 1.8°C. Some scientists believe a 2°C increase in the global mean temperature above pre-industrial levels is a threshold beyond which the threat of major and irreversible damage becomes more plausible.
Ice cores show that the levels of carbon dioxide (CO2) and methane are now far outside their ranges of natural variability over the last 500 000 years: the Earth's climate has entered a state unparalleled in recent prehistory. The average temperatures in the Arctic are rising twice as rapidly as in the rest of the world.
Sea-level rise caused by thermal expansion of water and the melting of glaciers and ice sheets will continue for the foreseeable future, with potentially huge consequences
Growing ocean acidification and warmer temperatures will probably also affect global food security. Diarrhoea and malaria will become more widespread.
Present trends do not favour greenhouse gas stabilisation.
Some greenhouse gases may persist in the atmosphere for up to 50 000 years.
Despite "impressive" success in phasing out ozone-depleting substances, the spring "hole" in the stratospheric ozone layer over the Antarctic is now larger than ever, allowing harmful ultraviolet solar radiation to reach the Earth.
More than 50 000 compounds are used commercially, hundreds more are added annually, and global chemical production is projected to increase by 85 per cent over the next 20 years.
Environmental exposure causes almost a quarter of all diseases.
Some of the progress achieved in reducing pollution in developed countries has been at the expense of the developing world, where industrial production and its impacts are now being exported.
Losses in total global farm production, due to insect pests, have been estimated at about 1 per cent.
Since 1987 the expansion of cropland has slackened, but land use intensity has increased dramatically.
Unsustainable land use is causing degradation, a threat as serious as climate change and biodiversity loss. It affects up to a third of the world's people, through pollution, soil erosion, nutrient depletion, water scarcity, salinity, and disruption of biological cycles.
By 2030 developing countries will probably need 120 million more hectares to feed themselves.
The loss of genetic diversity may threaten food security:
Fish: Consumption more than tripled from 1961 to 2001. Subsidies have created excess fishing capacity, estimated at 250 per cent more than is needed to catch the oceans' sustainable production.
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, over 30 per cent of amphibians, 23 per cent of mammals and 12 per cent of birds are threatened.
The intrusion of invasive alien species is 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.
A sixth major extinction is under way, this time caused by human behaviour. Yet to meet our growing demand for food will mean either intensified agriculture (using more chemicals, energy and water, and more efficient breeds and crops) or cultivating more land. Either way, biodiversity suffers.
One sign of progress is the steady increase in protected areas. But they must be effectively managed and properly enforced. And biodiversity (of all sorts, not just the "charismatic megafauna" like tigers and elephants) will increasingly need conserving outside protected areas as well.
About 60 per cent of the ecosystem services that have been assessed are degraded or used unsustainably;
Over half the world's 6 000 languages are endangered, and some believe up to 90 per cent of all languages may not survive this century.
Irrigation already takes about 70 per cent 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 per cent in developing countries and by 18 per cent in the developed world. GEO-4 says: "The escalating burden of water demand will become intolerable in water-scarce countries."
Water quality is declining too. There is rising concern about the potential impacts on aquatic ecosystems, of personal-care products and pharmaceuticals such as painkillers and antibiotics.. Globally, contaminated water remains the greatest single cause of human disease and death.
The Unequal World Edit
The amount of land per capita is about a quarter of what it was a century ago, and is expected to fall to about one-fifth of the 1900 level by 2050.
Urbanization is a significant pressure: by 2025 coastal populations alone are expected to reach six billion.
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 per cent 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 Edit
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 per cent 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.
West Asia Edit
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 Edit
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 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".
"Over the past 20 years, the international community has cut, by 95 per cent, the production of ozone-layer damaging chemicals; created a greenhouse gas emission reduction treaty along with innovative carbon trading and carbon offset markets; supported a rise in terrestrial protected areas to cover roughly 12 per cent of the Earth and devised numerous important instruments covering issues from biodiversity and desertification to the trade in hazardous wastes and living modified organisms."
"But, as GEO-4 points out, there continue to be 'persistent' and intractable problems unresolved and unaddressed. Past issues remain and new ones are emerging?from the rapid rise of oxygen 'dead zones' in the oceans to the resurgence of new and old diseases linked in part with environmental degradation. Meanwhile, institutions like UNEP, established to counter the root causes, remain under-resourced and weak," Achim Steiner, UN Under-Secretary General and UNEP Executive Director.