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GEO-3: GLOBAL ENVIRONMENT OUTLOOK  
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Environmental challenges

Despite these achievements, a growing world population - to more than 6 000 million people (and still climbing) - is exacerbating the demand on resources and services, and increasing the generation of wastes to meet many of these demands. Overall, policy measures have not been adequate to counteract the pressures imposed by increasing poverty and uncontrolled consumption. Preceding -> Chapter 2 sections show indisputable evidence of continuing and widespread environmental degradation.

  • Recent human impacts on the atmosphere have been enormous, with anthropogenic emissions a prime cause of environmental problems. Emissions of almost all greenhouse gases continue to rise.
  • Ground-level ozone, smog and fine particulates have emerged as significant health risks, triggering or exacerbating respiratory and cardiac problems, especially in vulnerable people such as children, the elderly and asthmatics, in developed and developing nations alike.
  • Overexploition of many of the surface water resources and great aquifers upon which irrigated agriculture and domestic supplies depend has resulted in more and more countries facing water stress or scarcity. About 1 200 million people still lack access to clean drinking water and some 2 400 million to sanitation services. The consequences include the deaths of 3-5 million people annually from water-related diseases.
  • The Earth's biological diversity is under increasing threat. The extinction rate of species is believed to be accelerating. Habitat destruction and/or modification are the main cause of biodiversity loss but invasive species are the second most important pressure.
  • There has been a sharp global trend towards increasingly intense exploitation and depletion of wild fish stocks. Numerous fisheries have collapsed and others are threatened with overexploitation.
  • Land degradation continues to worsen, particularly in developing countries where the poor are forced onto marginal lands with fragile ecosystems and in areas where land is increasingly exploited to meet food and agricultural needs without adequate economic and political support to adopt appropriate agricultural practices.
  • Many remaining forest ecosystems have been degraded and fragmented. Since 1972, extensive forest monocultures have been established in the developing world but these do not replace the ecological complexity of natural forests.
  • Crop and livestock production has contributed to the large increase in reactive nitrogen in the global biosphere, contributing to the acidification and eutrophication of ecosystems.
  • With almost half of the world's population living in less-developed countries, urban areas and megacities, infrastructure and municipal services are inadequate to accommodate millions of the urban poor. Urban air pollution and deteriorating water quality are having major health, economic and social impacts.
  • An increase in the frequency and intensity of natural disasters over the past 30 years has put more people at greater risk, with the greatest burden falling on the poorest communities.