by Maria Theresa Conception, League of Youth for Environment
Editors Note: This article was presented at the Student Empowerment for Transformation (SET) Program in Yong-in, Korea, August 2008 on the theme of Ecological Justice.
The Millennium Ecosystem Sssessment in 2005, a four-year study led by UNEP and scientific institutions conducted by 1,300 experts all over the world from 95 countries, presented the following general findings on the situation of the global ecological systems. First, humans have changed the ecosystems more rapidly and extensively in the last 50 years than in any other period in the known history of the world. Second, the degradation of the ecosystem has been equated to human well being. Third, degradation of ecosystems could grow worse during the first half of this century and is a barrier to achieving the UN Millennium Development Goals (MDGs). Lastly, the study also noted that reversing degradation of ecosystems while meeting increasing demands can be met under some scenarios involving significant policy and institutional changes.
An Ecosystem is composed of living, non-living factors, a self-sustaining, has several food chains, capable of producing food, recycling materials without outside input. In order to ascertain the over-all ecological situation, we need to look at the situation of the various systems comprising within the ecosystem.
Marine Systems. The marine systems are the world’s oceans. Global fishery catches from marine systems peaked in the late 1980s and are now declining despite increasing fishing effort. More than 2000 marine species are endangered, 30% of fish stocks are overexploited or depleted. The seabed, corals, mangrove forests and other critical ecosystems pay a high toll to unsustainable fishing and farming methods. The world’s demand for food and animal feed over the last 50 years has resulted in fishing pressure so strong that the target species and by catch has been reduced in much of the world to 1/10 of the levels prior to the onset of industrial fishing.
Island Systems. The islands are lands isolated by surrounding water and with a high proportion of coast to hinterland. Island states, together with their exclusive economic zones, cover 40% of the world’s oceans. Majority of recorded extinctions have occurred on island systems, although this pattern is changing, and over the past 20 years as many extinctions have occurred on continents as on islands.
Urban Systems. Urban systems are built environments with a high human density. The world’s urban population increased from about 200 million in 1900 to 2.9 billion in 2000, and the number of cities with populations in excess of 1 million increased from 17 in 1900 to 388 in 2000. Population congestion in urban centers is due to rural out-migration from absence of genuine agrarian reform, predominantly backward agricultural production, displacement by rural infrastructure developments and privatization and militarization. The problems associated with urban congestion is lack of available services such as housing, healthcare, sanitation, potable drinking water, electricity, among others.
Dryland Systems. Dryland systems are lands where plant production is limited by water availability. Dryland systems cover about 41% of Earth’s land surface and are inhabited by more than 2 billion people. Croplands cover approximately 25% of drylands. Dryland rangelands support approximately 50% of the world’s livestock. The current socioeconomic condition of people in dryland systems, of which about 90% are in developing countries, is worse than in other areas. Fresh water availability in drylands is projected to be further reduced from 1,300 cum per person per year in 2000, which is already below the threshold of 2,000 cubic meters required for minimum human wellbeing. 10-20% of the world’s drylands are degraded.
Polar Systems. Polar systems are high-latitude systems frozen for most of the year, including ice caps, areas underlain by permafrost, tundra, polar deserts, and polar coastal areas. Temperature in polar systems is on average warmer now than at any time in the last 400 years. Global warming trends and reduce the capacity of polar regions to act as a cooling system for Earth. Tundra constitutes the largest natural wetland in the world.
Forest Systems. Forest systems are lands dominated by trees, they are often used for timber, fuel wood, and non-wood forest products. In the last 300 years, global area of forest has been reduced by one half. Forests have effectively disappeared in 25 countries, and another 29 have lost more than 90% of their forest cover. Forest systems are associated with the regulation of 57% of total water runoff. About 4.6 billion people depend for all or some of their water on supplies from forest systems. From 1990 to 2000, the global area of temperate forest increased by almost 3 million hectares/year, while deforestation in the tropics occurred at an average rate exceeding 12 million hectares per year over the past two decades.
Cultivated Systems. Cultivated systems are lands dominated by domesticated species and used for crop, agro-forestry, or aquaculture production. Shifting cultivation, confined livestock production, and freshwater aquaculture, cover approximately 24% of total land area. In the last two decades, the major areas of cropland expansion were located in Southeast Asia, parts of South Asia, the Great Lakes region of eastern Africa, the Amazon Basin, and the US Great Plains. Most of the increase in food demand of the past 50 years has been met by intensification of crop, livestock, and aquaculture systems rather than expansion of production area. Increased yields of crop production systems have reduced the pressure to convert natural ecosystems into cropland, but intensification has increased pressure on inland water ecosystems, generally reduced biodiversity within agricultural landscapes, and it requires higher energy inputs in the form of mechanization and the production of chemical fertilizers. Cultivated systems provide only 16% of global runoff, although their close proximity to humans means that about 5 billion people depend for all or some of their water on supplies from cultivated systems. Such proximity is associated with nutrient and industrial water pollution.
Inland Water Systems. Inland water systems are permanent water bodies inland from the coastal zone and areas which are dominated by the permanent, seasonal, or intermittent occurrence of flooded conditions. Inland waters include rivers, lakes, floodplains, reservoirs, wetlands, and inland saline systems. Worst condition in terms of biodiversity, driven by declines in both the area of wetlands and the water quality in inland waters. It is speculated that 50% of inland water area (excluding large lakes) has been lost globally. Dams and other infrastructure fragment 60% of the large river systems in the world. Freshwater ecosystems have been modified through the creation of dams and through the withdrawal of water for human use. The construction of dams and other structures along rivers has moderately or strongly affected flows in 60% of the large river systems in the world.
Mountain Systems. Mountain systems are steep and high lands. Some 20% (or 1.2 billion) of the world’s people live in mountains or at their edges, and half of humankind depends, directly or indirectly, on mountain resources (largely water). Nearly all—90%—of the 1.2 billion people in mountains live in countries with developing or transition economies. About 4 billion people depend for all or some of their water on supplies from mountain systems. Some 90 million mountain people—almost all those living above 2,500 meters—live in poverty and are considered especially vulnerable to food insecurity*
Grasslands, Mediterranean forests, and tropical dry forests. Within terrestrial ecosystems, more than two thirds of the area of 2 of the world’s 14 major terrestrial biomes (temperate grasslands and Mediterranean forests) and more than half of the area of 4 other biomes (tropical dry forests, temperate broadleaf forests, tropical grassland, and wooded grasslands) had been converted (primarily to agriculture) by 1990. Among the major biomes, only tundra and boreal forests show negligible levels of loss and conversion, although they have begun to be affected by climate change.
There are 2 main categories of “drivers” that effect changes in the ecosystem, these are direct and indirect drivers. Direct drivers are straight forward influence on ecosystems, something easily seen, measured, observed. e.g. habitat change (land use change and physical modification of rivers or water withdrawal from rivers), overexploitation, invasive alien species, pollution, and climate change. Indirect drivers operates more diffusely, by altering one or more direct drivers e.g. populations, economic, socio-political, cultural and religious, science and technology, global trade.
Consider the following indirect drivers in the change in ecosystem.
Demographic Drivers. Global population doubled in the past 40 years and increased by 2 billion people in the last 25 years, reaching 6 billion in 2000. Developing countries have accounted for most recent population growth in the past quarter century.
Economic Drivers. Global economic activity increased nearly sevenfold between 1950 and 2000. Increase in per capita income results in increased pressure from ecosystems, as consumption of more processed goods is demanded. The level of per capita income was highest in North America, Western Europe, Australasia, and Northeast Asia, but both GDP growth rates and per capita GDP growth rates were highest in South Asia, China, and parts of South America. Likewise, growth in international trade has exceeded growth in global production for many years, and still growing.
Socio-political Drivers. Socio-political drivers include processes of decision-making—public participation, sectors, the mechanisms of dispute resolution, the role of the state relative to the private sector, and levels of education and knowledge. Over the past 50 years there have been significant changes in socio-political drivers. There is a declining trend in centralized authoritarian governments and a rise in elected democracies.
Cultural and Religious Drivers. These are values, beliefs, and norms that a group of people share. Culture conditions individuals’ perceptions of the world. It influences what they consider important, and suggests what courses of action are appropriate and inappropriate. These factors in turn influence the institutional arrangements for ecosystem management, as well as property rights over ecosystem services. For example, culture can influence consumption behavior and values related to environmental stewardship, and they may be particularly important drivers of environmental change.
Science and Technology. Greater understanding of nature, more efficient, less wasteful utilization of resources, increase food production, structural changes in economies, new management practices and policies that have increased the efficiency with which ecosystem services are used and provided.
In the last 200 years, growth of consumption of energy and materials has outpaced increases in materials and energy efficiency, leading to absolute increases of materials and energy use. The development and diffusion of scientific knowledge and technologies that exploit that knowledge has profound implications for ecological systems and human wellbeing. The twentieth century saw tremendous advances in understanding how the world works physically, chemically, biologically, and socially and in the applications of that knowledge to human endeavours.
Global Trade. Global trade magnifies the effect of governance, regulations, and management practices on ecosystems, enhancing good practices but worsening the damage caused by poor practices. Current trend in global trade exacerbates greater extraction of raw materials from developing countries for sale or trade to richer countries (liberalization, deregulation, privatization). Global trade does not address the root cause of underdevelopment in poorer countries, but actually exploits the situation to be able to extract more resources which will flow into richer countries.