The cumulative impact of ever more people using more resources is seriously degrading the foundations of life - the air, water, croplands, grasslands, forests and fisheries. In country after country, the natural resource base is shrinking while the pressures upon it - fuelled by increasing consumption and population growth - are increasing rapidly.
Almost half of the forests that originally covered the Earth have been cleared, fragmented, or otherwise degraded by man's activities.
- Every year, an area roughly the size of Nepal is cut, bulldozed or burnt, to meet the additional need for farmland, pastureland and forest products as human numbers expand.
- 75 per cent of the loss in global forest cover and 75 per cent of the historical growth of human population both took place in the 20th century.
- The underlying driving forces behind deforestation are poverty, population and economic growth, urbanisation and expansion of agricultural lands. Clearance for agriculture (slash and burn) is the largest cause of tropical deforestation, but logging is responsible for an estimated one-third of the total.
- The escalating consumption of forest products by developed and developing countries alike is another cause of forest loss. Globally, the use of paper and paperboard increased six-fold over the later half of the 20th Century, with the developed countries of North America, Europe and Asia accounting for most of it. As of 2004, the United States was the single biggest consumer of paper and paper products, averaging 331 kilograms per person per year, which amounts to roughly 30 per cent of the world's total consumption. On a per capita basis, Japan is second, at 250 kilograms per person.
Roundwood production has also increased in recent years. In 2005, the six top producers were the United States, India, China, Brazil, Canada and Russia, collectively accounting for 48 per cent of the world's total production. Since 1997, China's imports have more than tripled, making it the world's largest importer of wood and wood products. Demand for wood continues to escalate in most regions, mainly because of rapidly rising demand from transition economies, such as China.
Sources: Vital Signs 2007-08, Worldwatch Institute, Wash DC 2008. State of the World 2004, Worldwatch Institute, Wash DC 2004, p. 142.
- The destruction and fragmentation of forests and other wildlands are leading to extinction of plant species which could lead to new food sources and cures for cancer and other diseases. According to the World Conservation Union (IUCN}, some 11,000 plant and animal species face a high risk of extinction in the near future.
Land and soil
- Human activities have destroyed 11 per cent of the globe's arable land, the size of China and India combined. The loss of land and soils stretches the world's ability to provide food in support of today's population.
- Every year, the world's farmers must feed 75 million more people with 27 billion fewer tons of topsoil.
- In Africa, an estimated 500 million hectares of land have been affected by soil degradation since 1950 - including 65 per cent of the region's agricultural land.
- In China, between 1967 and 1990, arable land was reduced by an area equal to all the cropland in Denmark, France, Germany and the Netherlands combined.
- Degradation is caused by deforestation, soil erosion, over-use of pesticides and fertilisers, overgrazing and the clearance of marginal land for cultivation.
- Yields in Africa (which already produces 30 per cent less food per person than it did in 1970) could be halved within 40 years if degradation continues at present rates, with serious effects on food production.
- Low agricultural yields and high population growth have forced millions of small farmers to clear forests and cultivate fragile marginal lands, causing soil erosion and deepening rural poverty. Skewed land holdings (especially in South America), unsustainable logging, ranching, mining and plantation farming add to these problems.
- Many of the 160,000 people moving from rural to urban areas every day are 'environmental refugees' of one kind or another.
- Soil degradation in the drylands susceptible to desertification, which account for 40 per cent of the Earth's land surface, puts at risk the livelihoods of more than 1,000 million people.
- Susceptible areas include the savannahs of Africa, the Great Plains and the Pampas of the Americas, the Steppes of south-east Europe and Asia, the outback of Australia and the margins of the Mediterranean.
- Population growth in the marginal lands adds to insecurity as productive land per capita diminishes further.
- In West Asia, water shortages have combined with rangeland degradation due to overgrazing, wind erosion and poor irrigation, to force farmers to abandon agricultural land and migrate to cities.
- In parts of Africa, rapid population growth combined with shifting cultivation, suppression of fallow, drought and overgrazing, has led to a similar process.
Water is the most finite of the earth's resources. Between 1900 and 1995, global freshwater consumption rose six-fold - more than twice the rate of population growth.
- About one-third of the world's population already lives in countries with moderate to high water stress (where water consumption is more than 10 per cent of the renewable freshwater supply). If present consumption patterns continue, over 5 billion people - two out of every three living on earth -will live in water-stressed conditions by 2025, and by 2050 more than 2 billion people will live under conditions of high water stress.
- About 1.1 billion people (nearly 25 per cent of the population of the developing world) already lack access to safe drinking water and some 2.4 billion (half the population of the developing world) lack adequate sanitation. Insufficient water supplies, inadequate sanitation and poor hygiene are mainly responsible for the 3 million deaths each year from cholera and diarrhoeal diseases.
- Agriculture accounts for more than 70 per cent of freshwater consumption, and agricultural demand is likely to rise sharply to meet the need for additional food to feed the growing world population.
- On current trends, industrial water use will more than double by the year 2025, and in some industrialising countries, such as China, it may rise five-fold.
- Lack of water is already a major constraint to industrial and socio-economic growth in many parts of Africa and Asia and is likely to be one of the major factors limiting economic development in the future.
Air and the atmosphere
More people means more air pollution. Even with the availability of vastly improved technologies to limit pollution, population growth translates directly into more use of energy, more cars on the road, more factories and hence more dirty urban air. In turn, that often results in severe health problems.
© Hartmut Schwarzbach/Still Pictures
- Today, more than one billion people suffer from dangerously high air-pollution levels. Most of those live in sprawling Third World cities where industries and power plants have few, if any, pollution controls and where traffic jams are a perpetual feature of urban life. Up to 700,000 of those people die every year from the air they breathe.
- Even more serious, and little understood, is the health cost of indoor air pollution. The burning by 2 billion people of fuelwood, organic waste and coal (to heat homes and cook food in the developing world) causes respiratory disorders, especially to women and children, and is also linked to heart and lung disease mortality. The health impacts of forest fires may affect millions of people.
- Currently, the richest fifth of humanity consumes nearly 60 per cent of the world's energy, while the poorest fifth uses just 4 per cent. The combustion of fossil fuels (to run cars and industries in the richer countries) causes unhealthy pollution from carbon monoxide and sulphur and nitrogen oxides as well as the rapid build-up of carbon dioxide, the key to "heat-trapping" greenhouse gas.
Carbon dioxide and nitrogen loading
Annual global emissions of carbon dioxide from the burning of fossil fuels, cement manufacture and gas flaring reached a new high of 6,000 million tonnes carbon equivalent in 2000, and are are projected to reach 9,700 million tons carbon equivalent in 2020.
- Atmospheric concentrations of CO2 reached more than 360 parts per million in 1997, the highest level in 160,000 years.
- Human activities are seriously unbalancing the global nitrogen cycle. The advent of intensive agriculture, fossil fuel combustion and widespread cultivation of leguminous crops has led to huge additional quantities of nitrogen being deposited into terrestrial and aquatic ecosystems, which has raised nitrogen levels in drinking water, caused rapid plant growth in lakes and rivers and reduced plant diversity.
Nearly 1 billion people, most of them in developing countries, currently depend on fish for their primary source of protein. Altogether, seafood provides close to 20 per cent of the world's total animal protein intake.
- Seafood consumption has grown five-fold since 1950, and demand for food fish is projected to increase from about 75 million tonnes in 1994-95 to 110-120 million tonnes in 2010.
- Given the decline in fish stocks and the present degree of overfishing, this level of consumption is unlikely to be met, although carefully managed aquaculture is expected to fill some of the gap.
- Of the world's 15 major oceanic fisheries, 11 are in decline. The catch of Atlantic cod has dropped 70 per cent since 1970, and bluefin tuna stocks have declined by 80 per cent over the same period.
- Bottom-trawl fishing vessels, which trawl 5.8 million square miles of ocean bottom every year, harvest marine life indiscriminately, and up to 40 million tons are discarded every year.
- State of World Population 2001 (UN Population Fund report focusing on Population and Environmental Change).
- Global Environment Outlook 3 (this UNEP report provides an overview of the main environmental developments over the past three decades, and how social, economic and other factors have contributed to the changes that have occurred).
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