Sustainability and environmental management

Last updated

At the global scale sustainability and environmental management involves managing the oceans, freshwater systems, land and atmosphere, according to sustainability principles. [1] [2]

Contents

Land use change is fundamental to the operations of the biosphere because alterations in the relative proportions of land dedicated to urbanisation, agriculture, forest, woodland, grassland and pasture have a marked effect on the global water, carbon and nitrogen biogeochemical cycles. [3] Management of the Earth's atmosphere involves assessment of all aspects of the carbon cycle to identify opportunities to address human-induced climate change and this has become a major focus of scientific research because of the potential catastrophic effects on biodiversity and human communities. Ocean circulation patterns have a strong influence on climate and weather and, in turn, the food supply of both humans and other organisms.

Atmosphere

In March 2009, at a meeting of the Copenhagen Climate Council, 2,500 climate experts from 80 countries issued a keynote statement that there is now "no excuse" for failing to act on global warming and without strong carbon reduction targets "abrupt or irreversible" shifts in climate may occur that "will be very difficult for contemporary societies to cope with". [4] [5] Management of the global atmosphere now involves assessment of all aspects of the carbon cycle to identify opportunities to address human-induced climate change and this has become a major focus of scientific research because of the potential catastrophic effects on biodiversity and human communities.

Other human impacts on the atmosphere include the air pollution in cities, the pollutants including toxic chemicals like nitrogen oxides, sulphur oxides, volatile organic compounds and airborne particulate matter that produce photochemical smog and acid rain, and the chlorofluorocarbons that degrade the ozone layer. Anthropogenic particulates such as sulfate aerosols in the atmosphere reduce the direct irradiance and reflectance (albedo) of the Earth's surface. Known as global dimming the decrease is estimated to have been about 4% between 1960 and 1990 although the trend has subsequently reversed. Global dimming may have disturbed the global water cycle by reducing evaporation and rainfall in some areas. It also creates a cooling effect and this may have partially masked the effect of greenhouse gases on global warming. [6]

Oceans

A selection of the world's saltwater fish Pieni 2 0139.jpg
A selection of the world's saltwater fish

Ocean circulation patterns have a strong influence on climate and weather and, in turn, the food supply of both humans and other organisms. Scientists have warned of the possibility, under the influence of climate change, of a sudden alteration in circulation patterns of ocean currents that could drastically alter the climate in some regions of the globe. [7] Major human environmental impacts occur in the more habitable regions of the ocean fringes – the estuaries, coastline and bays. Eight point five of the world's population – about 600 million people – live in low-lying areas vulnerable to sea level rise. Trends of concern that require management include: over-fishing (beyond sustainable levels); [8] coral bleaching due to ocean warming, and ocean acidification due to increasing levels of dissolved carbon dioxide; [9] and sea level rise due to climate change. Because of their vastness oceans also act as a convenient dumping ground for human waste. [10] Remedial strategies include: more careful waste management, statutory control of overfishing by adoption of sustainable fishing practices and the use of environmentally sensitive and sustainable aquaculture and fish farming, reduction of fossil fuel emissions and restoration of coastal and other marine habitats. [11]

Freshwater

Water covers 71% of the Earth's surface. Of this, 97.5% is the salty water of the oceans and only 2.5% freshwater, most of which is locked up in the Antarctic ice sheet. The remaining freshwater is found in lakes, rivers, wetlands, the soil, aquifers and atmosphere. All life depends on the solar-powered global water cycle, the evaporation from oceans and land to form water vapour that later condenses from clouds as rain, which then becomes the renewable part of the freshwater supply. [12] Awareness of the global importance of preserving water for ecosystem services has only recently emerged as: during the 20th century, more than half the world's wetlands have been lost along with their valuable environmental services. Biodiversity-rich freshwater ecosystems are currently declining faster than marine or land ecosystems [13] making them the world's most vulnerable habitats. [14] Increasing urbanization pollutes clean water supplies and much of the world still does not have access to clean, safe water. [12] In the industrial world demand management has slowed absolute usage rates but increasingly water is being transported over vast distances from water-rich natural areas to population-dense urban areas and energy-hungry desalination is becoming more widely used. Greater emphasis is now being placed on the improved management of blue (harvestable) and green (soil water available for plant use) water, and this applies at all scales of water management. [13]

Land

Loss of biodiversity originates largely from the habitat loss and fragmentation produced by artificial land development, forestry and agriculture as natural capital is progressively converted to man-made capital. Land-use change is fundamental to the operations of the biosphere because alterations in the relative proportions of land dedicated to urbanisation, agriculture, forest, woodland, grassland and pasture have a marked effect on the global water, carbon and nitrogen biogeochemical cycles and this can negatively impact both natural and human systems. [3] At the local human scale major sustainability benefits accrue from the pursuit of green cities and sustainable parks and gardens. [15] [16]

Forests

Beech forest - Grib Skov, Denmark Grib skov.jpg
Beech forest – Grib Skov, Denmark

Since the Neolithic Revolution, human consumption has reduced the world's forest cover by about 47%. Present-day forests occupy about a quarter of the world's ice-free land with about half of these occurring in the tropics. [17] In temperate and boreal regions forest area is gradually increasing (with the exception of Siberia), but deforestation in the tropics is of major concern. [18]

Forests moderate the local climate and the global water cycle through their light reflectance (albedo) and evapotranspiration. They also conserve biodiversity, protect water quality, preserve soil and soil quality, provide fuel and pharmaceuticals, and purify the air. These free ecosystem services are not given a market value under most current economic systems, and so forest conservation has little appeal when compared with the economic benefits of logging and clearance which, through soil degradation and organic decomposition returns carbon dioxide to the atmosphere. [19] The United Nations Food and Agriculture Organization (FAO) estimates that about 90% of the carbon stored in land vegetation is locked up in trees and that they sequester about 50% more carbon than is present in the atmosphere. Changes in land use currently contribute about 20% of total global carbon emissions (heavily logged Indonesia and Brazil are a major source of emissions). [19] Climate change can be mitigated by sequestering carbon in reafforestation schemes, plantations and timber products. Also wood biomass can be utilized as a renewable carbon-neutral fuel. The FAO has suggested that, over the period 2005–2050, effective use of tree planting could absorb about 10–20% of man-made emissions – so monitoring the condition of the world's forests must be part of a global strategy to mitigate emissions and protect ecosystem services. [20] However, climate change may preempt this FAO scenario as a study by the International Union of Forest Research Organizations in 2009 concluded that the stress of a 2.5 °C (36.5 °F) temperature rise above pre-industrial levels could result in the release of vast amounts of carbon [21] so the potential of forests to act as carbon "sinks" is "at risk of being lost entirely". [22]

Cultivated land

A rice paddy. Rice, wheat, corn and potatoes make up more than half the world's food supply Rice Field.jpg
A rice paddy. Rice, wheat, corn and potatoes make up more than half the world's food supply

Feeding more than seven billion human bodies takes a heavy toll on the Earth's resources. This begins with the appropriation of about 38% of the Earth's land surface [23] and about 20% of its net primary productivity. [24] Added to this are the resource-hungry activities of industrial agribusiness – everything from the crop need for irrigation water, synthetic fertilizers and pesticides to the resource costs of food packaging, transport (now a major part of global trade) and retail. Food is essential to life. But the list of environmental costs of food production is a long one: topsoil depletion, erosion and conversion to desert from constant tillage of annual crops; overgrazing; salinization; sodification; waterlogging; high levels of fossil fuel use; reliance on inorganic fertilisers and synthetic organic pesticides; reductions in genetic diversity by the mass use of monocultures; water resource depletion; pollution of waterbodies by run-off and groundwater contamination; social problems including the decline of family farms and weakening of rural communities. [25]

All of these environmental problems associated with industrial agriculture and agribusiness are now being addressed through such movements as sustainable agriculture, organic farming and more sustainable business practices. [26]

Extinctions

The extinct dodo (Raphus cucullatus) ExtinctDodoBird.jpeg
The extinct dodo (Raphus cucullatus)

Although biodiversity loss can be monitored simply as loss of species, effective conservation demands the protection of species within their natural habitats and ecosystems. Following human migration and population growth, species extinctions have progressively increased to a rate unprecedented since the Cretaceous–Paleogene extinction event.[ citation needed ] Known as the Holocene extinction event this current human-induced extinction of species ranks as one of the world's six mass extinction events. Some scientific estimates indicate that up to half of presently existing species may become extinct by 2100. [27] [28] Current extinction rates are 100 to 1000 times their prehuman levels with more than 10% birds and mammals threatened, about 8% of plants, 5% of fish and more than 20% of freshwater species. [29]

The 2008 IUCN Red List warns that long-term droughts and extreme weather put additional stress on key habitats and, for example, lists 1,226 bird species as threatened with extinction, which is one eighth of all bird species. [30] [31] The Red List Index also identifies 44 tree species in Central Asia as under threat of extinction due to over-exploitation and human development and threatening the region's forests which are home to more than 300 wild ancestors of modern domesticated fruit and nut cultivars. [32]

Biological invasions

Kudzu (Pueraria lobata) infesting trees in Atlanta, Georgia, USA Kudzu on trees in Atlanta, Georgia.jpg
Kudzu (Pueraria lobata) infesting trees in Atlanta, Georgia, USA

In many parts of the industrial world land clearing for agriculture has diminished and here the greatest threat to biodiversity, after climate change, has become the destructive effect of invasive species. [33] Increasingly efficient global transport has facilitated the spread of organisms across the planet. The potential danger of this aspect of globalization is starkly illustrated through the spread of human diseases like HIV AIDS, mad cow disease, bird flu and swine flu, but invasive plants and animals are also having a devastating impact on native biodiversity. Non-indigenous organisms can quickly occupy disturbed land and natural areas where, in the absence of their natural predators, they are able to thrive. [34] At the global scale this issue is being addressed through the Global Invasive Species Information Network but there is improved international biosecurity legislation to minimise the transmission of pathogens and invasive organisms. Also, through CITES legislation there is control the trade in rare and threatened species. Increasingly at the local level public awareness programs are alerting communities, gardeners, the nursery industry, collectors, and the pet and aquarium industries, to the harmful effects of potentially invasive species. [35]

Resistance to change

The environmental sustainability problem has proven difficult to solve. The modern environmental movement has attempted to solve the problem in a large variety of ways. But little progress has been made, as shown by severe ecological footprint overshoot and lack of sufficient progress on the climate change problem. Something within the human system in preventing change to a sustainable mode of behavior. That system trait is systemic change resistance. Change resistance is also known as organizational resistance, barriers to change, or policy resistance. [36]

See also

Related Research Articles

<span class="mw-page-title-main">Deforestation</span> Conversion of forest to non-forest for human use

Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. About 31% of Earth's land surface is covered by forests at present. This is one-third less than the forest cover before the expansion of agriculture, with half of that loss occurring in the last century. Between 15 million to 18 million hectares of forest, an area the size of Bangladesh, are destroyed every year. On average 2,400 trees are cut down each minute. Estimates vary widely as to the extent of deforestation in the tropics. In 2019, nearly a third of the overall tree cover loss, or 3.8 million hectares, occurred within humid tropical primary forests. These are areas of mature rainforest that are especially important for biodiversity and carbon storage.

<span class="mw-page-title-main">Resource depletion</span> Depletion of natural organic and inorganic resources

Resource depletion is the consumption of a resource faster than it can be replenished. Natural resources are commonly divided between renewable resources and non-renewable resources. The use of either of these forms of resources beyond their rate of replacement is considered to be resource depletion. The value of a resource is a direct result of its availability in nature and the cost of extracting the resource. The more a resource is depleted the more the value of the resource increases. There are several types of resource depletion, including but not limited to: mining for fossil fuels and minerals, deforestation, pollution or contamination of resources, wetland and ecosystem degradation, soil erosion, overconsumption, aquifer depletion, and the excessive or unnecessary use of resources. Resource depletion is most commonly used in reference to farming, fishing, mining, water usage, and the consumption of fossil fuels. Depletion of wildlife populations is called defaunation.

<span class="mw-page-title-main">Fishery</span> Raising or harvesting fish

Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place. Commercial fisheries include wild fisheries and fish farms, both in freshwater waterbodies and the oceans. About 500 million people worldwide are economically dependent on fisheries. 171 million tonnes of fish were produced in 2016, but overfishing is an increasing problem, causing declines in some populations.

<span class="mw-page-title-main">Natural environment</span> Living and non-living things on Earth

The natural environment or natural world encompasses all biotic and abiotic things occurring naturally, meaning in this case not artificial. The term is most often applied to Earth or some parts of Earth. This environment encompasses the interaction of all living species, climate, weather and natural resources that affect human survival and economic activity. The concept of the natural environment can be distinguished as components:

<span class="mw-page-title-main">Environmental degradation</span> Any change or disturbance to the environment perceived to be deleterious or undesirable

Environmental degradation is the deterioration of the environment through depletion of resources such as quality of air, water and soil; the destruction of ecosystems; habitat destruction; the extinction of wildlife; and pollution. It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable. The environmental degradation process amplifies the impact of environmental issues which leave lasting impacts on the environment.

<span class="mw-page-title-main">Habitat destruction</span> Process by which a natural habitat becomes incapable of supporting its native species

Habitat destruction occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved to elsewhere or are dead, leading to a decrease in biodiversity and species numbers. Habitat destruction is in fact the leading cause of biodiversity loss and species extinction worldwide.

<span class="mw-page-title-main">Human impact on the environment</span> Impact of human life on Earth and environment

Human impact on the environment refers to changes to biophysical environments and to ecosystems, biodiversity, and natural resources caused directly or indirectly by humans. Modifying the environment to fit the needs of society is causing severe effects including global warming, environmental degradation, mass extinction and biodiversity loss, ecological crisis, and ecological collapse. Some human activities that cause damage to the environment on a global scale include population growth, neoliberal economic policies and rapid economic growth, overconsumption, overexploitation, pollution, and deforestation. Some of the problems, including global warming and biodiversity loss, have been proposed as representing catastrophic risks to the survival of the human species.

<span class="mw-page-title-main">Ecosystem service</span> Benefits provided by intact ecosystems

Ecosystem services are the various benefits that humans derive from healthy ecosystems. These ecosystems, when functioning well, offer such things as provision of food, natural pollination of crops, clean air and water, decomposition of wastes, or flood control. Ecosystem services are grouped into four broad categories of services. There are provisioning services, such as the production of food and water. Regulating services, such as the control of climate and disease. Supporting services, such as nutrient cycles and oxygen production. And finally there are cultural services, such as spiritual and recreational benefits. Evaluations of ecosystem services may include assigning an economic value to them.

<span class="mw-page-title-main">Marine ecosystem</span> Ecosystem in saltwater environment

Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply and 90% of habitable space on Earth. Seawater has an average salinity of 35 parts per thousand of water. Actual salinity varies among different marine ecosystems. Marine ecosystems can be divided into many zones depending upon water depth and shoreline features. The oceanic zone is the vast open part of the ocean where animals such as whales, sharks, and tuna live. The benthic zone consists of substrates below water where many invertebrates live. The intertidal zone is the area between high and low tides. Other near-shore (neritic) zones can include mudflats, seagrass meadows, mangroves, rocky intertidal systems, salt marshes, coral reefs, lagoons. In the deep water, hydrothermal vents may occur where chemosynthetic sulfur bacteria form the base of the food web.

<span class="mw-page-title-main">Forest management</span> Branch of forestry

Forest management is a branch of forestry concerned with overall administrative, legal, economic, and social aspects, as well as scientific and technical aspects, such as silviculture, forest protection, and forest regulation. This includes management for timber, aesthetics, recreation, urban values, water, wildlife, inland and nearshore fisheries, wood products, plant genetic resources, and other forest resource values. Management objectives can be for conservation, utilisation, or a mixture of the two. Techniques include timber extraction, planting and replanting of different species, building and maintenance of roads and pathways through forests, and preventing fire.

Anthropogenic metabolism, also referred to as metabolism of the anthroposphere, is a term used in industrial ecology, material flow analysis, and waste management to describe the material and energy turnover of human society. It emerges from the application of systems thinking to the industrial and other man-made activities and it is a central concept of sustainable development. In modern societies, the bulk of anthropogenic (man-made) material flows is related to one of the following activities: sanitation, transportation, habitation, and communication, which were "of little metabolic significance in prehistoric times". Global man-made stocks of steel in buildings, infrastructure, and vehicles, for example, amount to about 25 Gigatonnes, a figure that is surpassed only by construction materials such as concrete. Sustainable development is closely linked to the design of a sustainable anthropogenic metabolism, which will entail substantial changes in the energy and material turnover of the different human activities. Anthropogenic metabolism can be seen as synonymous to social or socioeconomic metabolism. It comprises both industrial metabolism and urban metabolism.

<span class="mw-page-title-main">Environmental impacts of animal agriculture</span> Impact of farming animals on the environment

The environmental impacts of animal agriculture vary because of the wide variety of agricultural practices employed around the world. Despite this, all agricultural practices have been found to have a variety of effects on the environment to some extent. Animal agriculture, in particular meat production, can cause pollution, greenhouse gas emissions, biodiversity loss, disease, and significant consumption of land, food, and water. Meat is obtained through a variety of methods, including organic farming, free-range farming, intensive livestock production, and subsistence agriculture. The livestock sector also includes wool, egg and dairy production, the livestock used for tillage, and fish farming.

<span class="mw-page-title-main">Deforestation in Nigeria</span>

The extensive and rapid clearing of forests (deforestation) within the borders of Nigeria has significant impacts on both local and global scales.

This is a glossary of environmental science.

<span class="mw-page-title-main">Wild fisheries</span> Area containing fish that are harvested commercially

A wild fishery is a natural body of water with a sizeable free-ranging fish or other aquatic animal population that can be harvested for its commercial value. Wild fisheries can be marine (saltwater) or lacustrine/riverine (freshwater), and rely heavily on the carrying capacity of the local aquatic ecosystem.

The environmental impact of agriculture is the effect that different farming practices have on the ecosystems around them, and how those effects can be traced back to those practices. The environmental impact of agriculture varies widely based on practices employed by farmers and by the scale of practice. Farming communities that try to reduce environmental impacts through modifying their practices will adopt sustainable agriculture practices. The negative impact of agriculture is an old issue that remains a concern even as experts design innovative means to reduce destruction and enhance eco-efficiency. Animal agriculture practices tend to be more environmentally destructive than agricultural practices focused on fruits, vegetables and other biomass. The emissions of ammonia from cattle waste continue to raise concerns over environmental pollution.

<span class="mw-page-title-main">Climate change and fisheries</span>

Fisheries are affected by climate change in many ways: marine aquatic ecosystems are being affected by rising ocean temperatures, ocean acidification and ocean deoxygenation, while freshwater ecosystems are being impacted by changes in water temperature, water flow, and fish habitat loss. These effects vary in the context of each fishery. Climate change is modifying fish distributions and the productivity of marine and freshwater species. Climate change is expected to lead to significant changes in the availability and trade of fish products. The geopolitical and economic consequences will be significant, especially for the countries most dependent on the sector. The biggest decreases in maximum catch potential can be expected in the tropics, mostly in the South Pacific regions.

<span class="mw-page-title-main">Biodiversity loss</span> Extinction of species or loss of species in a given habitat

Biodiversity loss happens when plant or animal species disappear completely from Earth (extinction) or when there is a decrease or disappearance of species in a specific area. Biodiversity loss means that there is a reduction in biological diversity in a given area. The decrease can be temporary or permanent. It is temporary if the damage that led to the loss is reversible in time, for example through ecological restoration. If this is not possible, then the decrease is permanent. The cause of most of the biodiversity loss is, generally speaking, human activities that push the planetary boundaries too far. These activities include habitat destruction and land use intensification. Further problem areas are air and water pollution, over-exploitation, invasive species and climate change.

<span class="mw-page-title-main">Sustainable Development Goal 15</span> 15th of 17 Sustainable Development Goals to protect life on land

Sustainable Development Goal 15 is about "Life on land". One of the 17 Sustainable Development Goals established by the United Nations in 2015, the official wording is: "Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss". The Goal has 12 targets to be achieved by 2030. Progress towards targets will be measured by 14 indicators.

<span class="mw-page-title-main">Fruit production and deforestation</span>

Fruit production is a major driver of deforestation around the world. In tropical countries, forests are often cleared to plant fruit trees, such as bananas, pineapples, and mangos. This deforestation is having a number of negative environmental impacts, including biodiversity loss, ecosystem disruption, and land degradation.

References

  1. "The Economics and Social Benefits of NOAA Ecosystems Data and Products Table of Contents Data Users". NOAA. Archived from the original on 2010-03-25. Retrieved 2009-10-13.
  2. Buchenrieder, G., und A.R. Göltenboth: Sustainable freshwater resource management in the Tropics: The myth of effective indicators, 25th International Conference of Agricultural Economists (IAAE) on “Reshaping Agriculture’s Contributions to Society” in Durban, South Africa, 2003.
  3. 1 2 Krebs (2001) pp. 560–582.
  4. University of Copenhagen (March 2009) "Key Messages from the Congress" Archived 2009-03-16 at the Wayback Machine News item on Copenhagen Climate Congress in March 2009. Retrieved on: 2009-03-18.
  5. Adams, D. (March 2009) "Stern attacks politicians over climate 'devastation'". The Guardian. Retrieved on: 2009-03-18.
  6. Hegerl, G.C. et al. (2007). "Climate Change 2007: The Physical Science Basis." Chapter 9, "Understanding and Attributing Climate Change." Contribution of Working Group 1 to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. p. 676. Cambridge: Cambridge University Press. Full report at: IPCC Report. Retrieved on: 2009-03-18.
  7. Kerr, R.A. (2004). "A slowing cog in the North Atlantic ocean's climate machine." Science304: 371–372. Retrieved on: 2009-04-19.
  8. Black, R. (November 2006). "'Only 50 years left' for sea fish". BBC News, UK.
  9. Harrabin, R. (March 2009). "'Coral lab' offers acidity insight". BBC News, UK. Retrieved on: 2009-03-18.
  10. Schukman, D. (March 2009). "Sea rise 'to exceed expectations'". BBC News, UK. Retrieved on: 2009-03-18.
  11. Lindenmayer & Burgman (2005).
  12. 1 2 Clarke & King (2006) pp. 20–21.
  13. 1 2 Hoekstra, A.Y. (2006). "The Global Dimension of Water Governance: Nine Reasons for Global Arrangements in Order to Cope with Local Problems." Value of Water Research Report Series No. 20 UNESCO-IHE Institute for Water Education. Retrieved on: 2009-03-18.
  14. World Wide Fund for Nature (2008). Living Planet Report 2008. Retrieved on: 2009-03-29.
  15. Organic Gardening Techniques, Missouri University Extension. October 2004. Retrieved June 17, 2009.
  16. Sustainable Gardening & Food Production Archived 2010-06-21 at the Wayback Machine , Daniel Boone Regional Library. Retrieved June 17, 2009
  17. World Resources Institute (1998). World Resources 1998–1999. Oxford: Oxford University Press. ISBN   0-19-521408-0.
  18. Groombridge & Jenkins (2002).
  19. 1 2 Food and Agriculture Organisation (2006). "Global Forest Resources Assessment 2005: Progress Towards Sustainable Forest Management." Forestry paper 147. Rome: FAO. Retrieved on: 2009-04-17.
  20. IPCC (2006). IPCC Guidelines for National Greenhouse Inventories, Vol.4, Agriculture, Forestry, and other Land Uses. Japan: Institute for Global Environment Strategies.
  21. Kinver, M. (April 2009). "Key role of forests 'may be lost'" BBC News, UK. Retrieved on: 2009-04-19.
  22. Dold, M. (April 2009). "New Study Warns Damage to Forests from Climate Change Could Cost the Planet Its Major Keeper of Greenhouse Gases.". IUFRO News. Retrieved on: 2009-04-20.
  23. Food and Agriculture Organization (June 2006). "Food and Agriculture Statistics Global Outlook." Rome: FAO Statistics Division. Retrieved on: 2009-03-18.
  24. Imhoff, M.L. et al. (2004). "Global Patterns in Human Consumption of Net Primary Production." Nature429: 870–873.
  25. Tudge (2004).
  26. World Business Council for Sustainable Development Archived 2009-04-10 at the Wayback Machine This web site has multiple articles on WBCSD contributions to sustainable development. Retrieved on: 2009-04-07.
  27. Wilson (2002)
  28. Leakey & Lewin (1995)
  29. Millennium Ecosystem Assessment, pp. 42–47.
  30. Kinver, M. (May 2008). Climate 'accelerating bird loss. BBC News, UK. Retrieved on: 2009-04-17/
  31. BBC News (March 2009) "Climate 'hitting Europe's birds'." BBC News, UK. Retrieved on: 2009-04-17.
  32. Gill, V."The wild ancestors of common domestic fruit trees are in danger of becoming extinct, scientists have warned." BBC News, UK. Retrieved on: 2009-05-09.
  33. Randall (2002).
  34. Krebs (2001) pp. 190–205.
  35. Blood (2001).
  36. John Sterman, "Business Dynamics: Systems Thinking and Modeling for a Complex World, 2000, pp 5-10.

Sources