Major Issues[ Land | Forest | Biodiversity | Water | Marine and Coastal Environments | Atmosphere | Urban and Industrial Environments | Polar Environments ]
Issues pertaining to land are of greatest concern in regions where food security is a priority, notably in Africa and West Asia. Land availability, abatement of land degradation, and efficient land management are driven by the food security demands of growing populations, which result in expanded cultivation and agricultural intensification-unless met by food trade.
In countries with limited economic resources, the food trade option is not generally sufficient to cover the magnitude of growing needs. Rapid introduction and adoption of intensification technologies are also limited by economic and cultural complexities, leaving the expansion of cultivation into marginal lands and wilderness areas as the prime short- to medium-term option for increasing production. As a consequence, forests, woodlands, or grasslands are destroyed or degraded and natural ecosystems are fragmented, with negative impacts on biodiversity. Poor land management further increases susceptibility of soils to erosion, reduces moisture retention, and accelerates leaching of nutrients. Degradation feeds back into a cycle of declining productivity and, in the worst cases, desertification or the irreversible degeneration of marginal lands.
Considerable anxiety still remains in several regions (Africa, Asia-Pacific, and West Asia) where there is a relative scarcity of land per capita and land quality is poor. Waterlogging, salinization, and erosion (by both wind and water) of soil resources are of special concern, while desertification remains a serious worry in the drier zones of the regions. Loss of limited agricultural land to alternative uses is another particular concern in West Asia.
Human-made fire influences land degradation in the woodlands and grasslands of Africa, and the problem is complicated by long-established cultural practices. The residual impacts of civil conflict in Africa also pose problems regarding the availability and degradation of land. Significant tracts of land remain effectively inaccessible due to the widespread laying of mines during past military conflicts and the environmental impact of refugees is substantial in a number of countries.
Limited land availability is also of particular concern to small island states world-wide. Land degradation through erosion and significant desertification of drylands in the past is an ongoing problem in Latin America. Despite the remaining high number of natural ecosystems in Latin America, unrestrained expansion of the agricultural frontier there could have serious impacts on wilderness areas.
In Europe, problems of land degradation relate mainly to irreversible erosion, acidification, and pollution of soils and the subsequent economic impacts. Generally speaking, soil degradation is no longer a priority concern in North America, given the widespread adoption of conservation-based farming practices. More attention is placed on problems relating to land pollution, and water contamination. Improving poor agricultural practices, where evident, is vigorously targetted in order to reduce erosion and productivity losses.
The decline of natural forest in developing regions has been considerable between 1980 and 1990. Total losses in the tropics have been greatest in Latin America and the Caribbean, followed by those in Africa and in Asia and the Pacific. Industrialization, population growth and related agricultural expansion, and forest product trade are the main driving forces in reducing forest cover in these regions. Rates of deforestation are of particular concern in Asia and the Pacific, and in the highland states of West Asia. In West Asia, the opening up of woodlands has caused increased susceptibility to erosion and land degradation in general.
In Africa, remaining forests are under great pressure from agricultural expansion and the use of wood as fuel, with pressure likely to increase with rising population, continued dependence on subsistence agriculture, and an absence of alternatives to wood as fuel. Declining productivity, increased climatic variability, and greater susceptibility to flooding have also been attributed in part to accelerated deforestation on the African continent.
Forest area is currently rather stable in Europe and North America, as it has been for the past century. However, forests in Europe suffer from acidification, and the boreal (northern) forests in Siberia are being heavily exploited. The removal of old-growth forests raises protests in North America and Europe.
Conservation of biodiversity is of concern in all regions, with most countries having adopted the principles of the Convention on Biological Diversity. As a result, many have taken steps domestically to protect and conserve natural habitats and related biodiversity. The degree of success and national priority accorded to biodiversity varies widely across regions, however.
Latin America accords biodiversity a high priority, while Asia and the Pacific more recently accepted its legitimacy as an issue of both national and international concern. Both Europe and North America accord a high priority to the conservation of biodiversity, although the United States has not signed the Convention on Biological Diversity. Many African countries, with a view toward the economic potential of revenues from wildlife tourism, also recognize the need for biodiversity conservation.
Yet competition for scarce land resources and the rising demand for food production represent important constraints. Habitat loss caused by development pressure and the overexploitation of fisheries, ground-water depletion, and hunting are threatening biodiversity. Fish stocks in parts of North America and Europe have also been seriously depleted. One of the more pernicious effects world-wide of deforestation and the conversion of other natural lands such as woodlands and grasslands is the fragmentation of habitats and the negative effect this has on biodiversity.
On a global scale, the problem of water is more a case of distribution and quality than one of quantity. Water is rarely a region-wide concern, with some notable exceptions, but all regions have some problems related to either ground-water or surface water resources.
The development and efficient management of water resources is of particular concern in West Asia and parts of Africa, particularly the Sudano-Sahelian belt and the Horn of Africa. Not only is there relative scarcity of water resources, but these locations also face high evaporation rates, high levels of anticipated future demands, and the transboundary problems associated with water resources. Measured against the future requirements of urban centres, agriculture, and industry, access to adequate quantity and quality of water will soon become problematic in those areas of West Asia, Africa, and the parts of Latin America that have mega-cities. In some cases, competition for water may lead to conflicts over transboundary resources.
In other regions, overexploitation of surface waters disrupts flow regimes, affecting aquatic ecosystems and the quantity and quality of water supplies downstream, a situation that can lead to hostility between water users. Overexploitation of ground water lowers water tables, which may damage wetlands, cause ground subsidence, and induce salt-water intrusion in coastal aquifers.
Many cities world-wide that depend on ground water as the primary water supply are experiencing problems caused by the deterioration of these reserves. In large cities in many regions, the discharge of inadequately treated sewage subjects aquatic communities to severe deoxygenation and possibly ammonia toxicity. Humans risk microbial infection if recycled water is not adequately treated, as happens in areas marginal to cities, including those mega-cities in the less developed parts of Asia and Latin America.
Europe also suffers from contamination of much-needed ground-water resources as well as shared surface water resources as a result of excessive agricultural fertilizer and pesticide use. Concerns over water in North America relate mainly to municipal supplies and rural water quality and their consequent impact on health.
A high proportion of the world's population resides in coastal areas, and many more derive benefit from marine resources such as food, employment, or tradable commodities. Marine coastal ecosystems and the accompanying biodiversity are particularly vulnerable to land-based sources of contamination.
An estimated one third of the world's coastal regions are at high risk of degradation, with the greatest threat apparent in Europe. Asia and the Pacific, the wider Caribbean, and West Asia also face problems related to land-based sources of urban waste discharge and industrial pollution. Shipping traffic and oil spills represent a particular threat in West Asia and the Caribbean. Threats to the coastal and marine resources in Latin America and the Caribbean rise considerably with tourism, infrastructure development, and the discharge of sediment, waste, and industrial contaminants. Coastal erosion is a growing problem in a number of African countries where local communities are adversely affected by changing sedimentation patterns due to upstream dam construction or increased erosion in degraded catchments. Eutrophication in the Baltic, Black, and North seas is also a problem-and a severe one in localities bordering the Mediterranean and Caspian seas.
The overexploitation of marine fisheries and the economic impact of such practices cause widespread concern in parts of Asia and the Pacific, North America, Europe, and West Asia. In addition, small island states and coastal communities of South-East Asia, the Pacific, the Caribbean, and low-lying areas of Europe have special concerns over the future impacts of climate change on sea level, especially as the precise local effects cannot yet be determined. Climate change may also affect ocean mixing and circulation patterns, with significant repercussions on the productivity of marine ecosystems and the location of fisheries.
Polluted air has many adverse impacts: on human health, through inhalation of harmful gases and particulates; by damaging biotic and ecosystem functions; through accelerated deterioration of building materials; and by inducing climatic disturbances. In the short term, it is the human health risks, especially chronic respiratory illnesses, that are of greatest concern.
Damage to ecosystems through acidification and acid rain is also causing growing anxiety in some regions. Once regarded only as a problem in Europe and parts of North America, airborne pollution has become apparent in parts of Asia and the Pacific and in Latin America-fuelled literally by the by-products of industrialization. The cause lies largely in the burning of fossil fuels for industry and transport in countries with developed and rapidly growing market economies. The long-range transportation and transboundary effects of such atmospheric processes are increasingly of global concern.
The concentration of people and activities close to urban and industrial areas is of particular concern in Europe-especially in eastern Europe, where poor air quality is considered the most common environmental problem. Large cities in Asia and the Pacific, Latin America, and North America also experience problems of local air pollution. The rapid growth of a number of African cities points to emerging problems of poor urban air quality there in the near future.
The Montreal Protocol clearly illustrated the ability of the international community to quickly mobilize and respond to a scientifically identified environmental problem stemming from ozone depleting substances. Despite coordinated action world-wide, damage to the ozone layer continues faster than expected. The resulting increase of ultraviolet-B radiation in the lower atmosphere has adverse impacts on human health (skin cancer, cataracts, and reduced immune efficiency), on terrestrial and aquatic ecosystems (reduced species survival and productivity), and on building materials (faster deterioration). While ozone depletion continues in the upper atmosphere, rising ozone concentrations in the troposphere have focused world attention on the extent of the human contribution to this problem.
Global warming is yet another universal problem emanating from a changing atmosphere. All regions express concern over global warming and place emphasis on the need for adaptive mechanisms to cope with accompanying climate variability and sea level change.
Developing and rapidly industrializing regions, faced with rapidly increasing populations as a result of high birth rates and in-migration, are battling with the accompanying environmental problems of unplanned urban growth and emerging mega-cities (those with more than 10 million inhabitants). Estimates indicate that by the year 2000, cities will fall in this category. The rise of such cities in Asia and the Pacific, Latin America, and Africa has been accompanied by the proliferation of slums and squatter settlements without access to basic infrastructure, water, or sanitation. Eastern Europe is also affected to some degree by this phenomenon, as are a number of cities in West Asia, especially those experiencing massive rural-to-urban migration.
The resultant concentration of people and of industrial and domestic effluents and waste impose unwieldy demands on urban environments. Poor urban and solid waste management in African cities is particularly problematic in view of the potentially damaging effects on human health. At the same time, there is a move in western Europe and North America toward greening cities and encouraging reduced urban population densities. The increasing number of single-person households in these latter regions, however, is placing increased demands on energy resources and the management of wastes.
Wherever management and disposal of industrial and domestic waste is inadequate, these sources of soil and water contamination pose potential hazards to human and ecosystem health. Consequently, improved waste management is a priority in urban and industrial areas of Europe. Changing consumption patterns and recycling are encouraged by governments, but thousands of contaminated sites remain due to improper waste disposal, particularly in Eastern Europe and the former Soviet Union.
Investment in new technologies is helping improve waste management in much of western Europe. In the Asia-Pacific region, rapidly growing economic activity and populations have stimulated solid and industrial waste generation to the extent that it now poses a serious environmental health problem.
In the industrializing countries of Latin America, industrial effluent and solid wastes pose increasing hazards to human health because of the close proximity of large populations to the contaminants. Waste management receives serious attention throughout North America due to the ever increasing quantities of municipal and industrial waste generated. The region is the leading producer of waste on the planet.
Chemical pollutants are emerging world-wide as a pervasive environmental concern of highest priority. Environmental emergencies involving chemicals appear to be steadily increasing, and mounting evidence is being put forth about serious health risks posed by persistent organic pollutants. Radioactive pollution remains a top environmental concern of countries in northern and eastern Europe, particularly those of the former Soviet Union.
The Arctic and Antarctic regions represent the world's largest remaining natural areas and pristine environments. Polar regions have long been recognized as important indicators of the planet's overall health, especially with regard to global warming, long-range transport of pollutants, and, in the case of Antarctica, atmospheric ozone concentrations. For these reasons, universal concern generated international action regarding the state of the environment in both regions.
In the Arctic, overexploitation of fisheries, mining, the presence of forest industries, and infrastructure development all threaten natural habitats and open the possibility for direct degradation and pollution of resources. A fragile ecosystem, the region is particularly sensitive to land degradation and erosion. Biodiversity is also fragile, with few but highly specialized and adapted species.
Military and industrial interest in the Arctic has had a negative impact through dumping of radioactive wastes and accidents involving similar materials. While radioactivity of Arctic seas is low compared with other north European seas, it is still considered one of the main threats to the Arctic environment. Traditional societies have also increased their exploitation of resources through a shift towards non-traditional activities.
The vast extent of Antarctica's sea ice and continental ice sheet are especially important with regard to the modelling and assessment of climate change and sea level rise. Its unique geographical location and pristine environment also enable the monitoring of air pollution against a background of minimum interference and high sensitivity to change. Antarctica has unique marine and terrestrial life forms that require protection from growing international interest in the continent. Related tourism is a growing industry that can have a serious impact if not controlled.