Sustainable Biosphere

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Sustainable biosphere

The biosphere is the region of the earth that supports life; it includes all land, water, and the thin layer of air above the earth. A sustainable biosphere is one with the continuing ability to support life.

Some scientists have suggested that the oceans and atmosphere in the biosphere adjust to ensure the continuation of life—a theory known as the Gaia hypothesis . British scientist James Lovelock first proposed it in the late 1970s. He argued that in the last 4,500 years of the earth's approximately five billion years of existence, humans have been placing increasingly greater stress on the biosphere. He called for a new awareness of the situation and insisted that changes in human behavior were necessary to maintain a biosphere capable of supporting life. Maintaining a sustainable biosphere involves the integrated management of land, water, and air.

The land management practices that many believe are necessary for sustaining the biosphere require conservation and planting techniques that control soil erosion . These techniques encourage farmers to use organic fertilizers instead of synthesized ones. Recycled manure and composted plant materials can be used to put nutrients back into the soil instead of increasing pollution in the environment . Crop rotation reduces crop loss to insects and also increases soil fertility. Monitoring pest populations helps determine the best times as well as the best methods for eliminating them, and using pesticides only when needed lowers pollution of soil and water and prevents insects from developing resistances.

China provides one model of good land management. Through techniques of sustainable agriculture which emphasize organic farming , China has met (though not exceeded) the nutritional needs of most of its people. On Chinese farms, methane digesters recycle animal wastes, by-products, and general refuse; the gas produced from the digesters is in turn used as an energy source. Biological controls are also used to reduce the number of harmful insects and weeds. Crops are selected for their ability to grow in particular locations, and strip-farming and terracing help conserve the soil. Crops that put certain nutrients in the soil are planted in alternate rows with crops that deplete those nutrients. Forests, important for watershed and as a fuel source, are maintained. Fish farming, or aquaculture , is widely practiced, and the fish raised on these farms produce about 10 times more animal protein than livestock raised on the same amount of land. In China, agriculture relies upon human labor rather than more expensive and environmentally harmful machinery, which has the added advantage of keeping millions of people gainfully employed.

Another important aspect of land management is biodiversity . Each organism is specially suited for its niche , yet all are interconnected, each depending on others for nutrients, energy, the purification of wastes, and other needs. Plants provide food and oxygen for animals, sustain the hydrocycle, and protect the soil. Animals help pollinate plants and give off the carbon dioxide that plants need to generate energy. Microorganisms recycle wastes, which returns nutrients to the system. The activity of many of these organisms is directly useful to humans. Additionally, having a broad range of organisms means a broad source of genetic material from which to create new, as well as better, crops and livestock. However, a reduction in the number of species reduces biological diversity. Hunting can destroy species, as can eliminating habitats by cutting down forests, draining wetlands , building cities and polluting excessively.

The water portion of the biosphere has two interconnected parts. Freshwater lakes and rivers account for about 3% of the earth's water, while the oceans contain the other 97%. Oceans are important to the biosphere in a number of ways. They absorb some of the gases in the air, regulating its composition, and they influence climate all over the earth, preventing drastic weather changes. Additionally, the ocean contains a myriad of plant and animal species, which provide food for humans and other organisms and aid in maintaining their environment.

However, according to many scientists, exploitation of the oceans must be curtailed to ensure that they remain viable. Their argument is that species are too often harvested until they are destroyed, creating an imbalance in the ecosystem , and that fishing quotas that do not allow populations to be depleted faster than they can be replaced should be set and enforced. Rather than harvesting immature fish, the commercial fishing industry should release them, thus keeping the species population in equilibrium. Pressure must also be taken off individual species, and interactions in the ocean ecosystem should be examined. A strategy designed to consider these factors would benefit the whole ocean community as well as humans. Pollution of the ocean should also be reduced. Pollution can take the form of garbage , sewage, toxic wastes, and oil. In excess, these harm the organisms of the ocean, which in turn harms humans. Disposal of these substances should be controlled through, though not limited to, sewage treatment , discharge restrictions and improved dispersal techniques.

Although freshwater is a renewable resource, care needs to be taken to keep it clean. Wise water management, which includes monitoring water supplies and water quality , can ensure that everyone's needs are met. Agriculture and commercial fishing require water, and manufacturing industries use water in many of their processes. Households consume water in cooking, cleaning, and drinking, among other activities. Without water, certain recreations such as water skiing and swimming would be impossible to enjoy. Wildlife and fish also need water to survive.

Pollutants reduce and damage the freshwater supply. Pollutants include chemicals , sewage, toxic waste, hot water, and many other organic and inorganic materials. Waste leaching from landfills contaminates groundwater , and surface water is corrupted by wastes dumped into the water by polluted groundwater flowing into the stream or lake, or by polluted rain. Like oceans, freshwater can break down small amounts of pollutants, but large amounts place great pressure on the system. Disposal of potential pollutants requires monitoring and treatment. A useful strategy is to balance the demands of humans with the needs of the ecosystem, emphasizing conservation and pollution reduction.

As with land and water, the atmosphere has been adversely affected by pollution. Pollution in the air causes such phenomena as smog , acid rain , atmospheric inversion , and ozone layer depletion . Smog lowers the amount of oxygen in the air, which can cause health problems. Acid rain destroys plants, animals, and freshwater supplies. Atmospheric inversion exists when air pollution is unable to escape because a layer of warm air covers a layer of cooler air, trapping it close to the ground. Certain compounds, such as chlorofluoromethanes, thin the ozone layer by combining with ozone to split it apart. A thinner ozone layer provides less protection from the sun's ultraviolet radiation , which promotes skin cancer in humans and reduces the productivity of some crops. Reducing or eliminating harmful emissions can also control air pollution.

Sustainable development is one approach to keeping the biosphere healthy. This method attempts to increase local food production without increasing the amount of land taken. It involves nature conservation and environmental monitoring , and it advocates encouraging and training local communities to participate in maintaining the environment. The goal is to balance human needs with environmental needs, and proponents of this view maintain that economic growth depends on renewable resources, which in turn depends on permanent damage to the environment being kept at a minimum.

The Ecological Society of America published the Sustainable Biosphere Initiative (SBI) in the early 1990s. This document was an attempt to define ecological priorities for the twenty-first century, and it is based on the realization that research in applied ecology is necessary for better management of the earth's resources and of the systems that support life. The SBI calls for basic ecological research and emphasizes the importance of education and policy and management decisions informed by such research.

The SBI sets out criteria for determining which research projects should be pursued, and it proposes three top research priorities: global change, biodiversity, and sustainable ecological systems. Global change research focuses on the causes and effects of various changes in all aspects of the biosphere (air, water, land). Biodiversity research focuses on both naturally occurring and human-caused changes in species. It also studies the consequences of those changes. Research on sustainable ecological systems exams the pressures placed on the biosphere, methods of correcting the damage and management of the environment to maintain life.

Creating a sustainable biosphere requires a cohesive policy for reducing consumption and seeking nonmaterial means of satisfaction. Many believe that such a cohesive policy would provide a much-needed focus for the many diverse environmental interests currently vying for public support.

[Nikola Vrtis ]