The Global Environment Picture Lecture #2 The Global Environment Picture Current environmental conditions and sustainability

Biosphere - the thin layer of life around the earth. The Earth does not belong to man, man belongs to the Earth – Chief Seattle Biosphere - the thin layer of life around the earth. It extends from the surface of the earth to approximately 5 miles above the earth and to about 5 miles into the deepest part of the ocean.   Within the biosphere, all living things exist in a close relationship with each other and with the non-living things necessary for their survival.

We depend on the earth for our resources. Natural Resources - any natural substance that living things use. Examples - sunlight, air, water, soil   Renewable Resource - resources that are continually being replaced even as they are being used. Example - solar energy, trees, fish Renewable resources CAN be depleted. Example: Cut down trees faster than they can re-grow. Nonrenewable Resources - Resources that cannot be replaced once they are consumed. Examples - copper ore, Fossil fuels

Environmental Problems are often very complicated. Example: Preventing pollution can be expensive. Cleaning it up once it has happened is even more expensive.   Example II: Protecting an endangered species may threaten jobs and slow economic development in a region.

Global Environmental Problems Some Environmental problems are Global Problems. These are the 4 main ones: Human population Degradation of soils Atmospheric changes (global warming) Loss of biodiversity

Human Overpopulation Human Population > 6.5 Billion The human population has grown 2 billion in just the past 25 years and it is increasing more rapidly than any other time in history. Water quantity and quality issues may be the most critical issues in the 21st century.

A Divided World World Bank estimates more than 1.4 billion people live in extreme poverty earning < $1 (U.S.) per day. Poor are often both victims and agents of environmental degradation. They are trying to meet their present survival needs at the cost of long term sustainability. Cycle of poverty continues over generations as people who are malnourished and ill cannot work productively and raise healthy children.

A Divided World About 1/5 of the world’s population lives in countries with per capita income > $25,000 per year (U.S.). The other 4/5 lives in middle or low income countries. Gap between rich and poor continues to increase. The gap affects many quality of life indicators.

Quality of Life Indicators

Is There Enough for Everyone? Rich nations consume an inordinate share of the world’s resources and produce an unsustainable amount of pollution. The U.S. makes up 4.6% of the world’s population, but consumes 25% of all oil production and generates 50% of all toxic wastes in the world. If all the residents of China were to match American consumption, it would take four extra planet Earths to support them using current technology.

Economic Progress Over the past 50 years, the world’s Gross Domestic Product (GDP) increased from $2 trillion to $22 trillion. Since WW II, average real income in developing countries has doubled and life expectancy has increased by 30%. BUT The worldwide gap between rich and poor has widened.

Degradation of Soils Food is inequitably distributed across the globe and 2/3 of agricultural lands show signs of soil degradation. Fertile soil is necessary for plant growth and food production The worlds soils are being degraded by erosion   Erosion - the process of soil particles being taken away by wind or water. Eroded land cannot support vegetation, which supports everything else.

Atmospheric changes Fossil fuel reserves are diminishing and the burning of fossil fuels causes pollution and global warming. Global warming - Warming of the earth’s atmosphere due to the greenhouse effect of carbon dioxide and other gases. Thought to be one of the most serious problems facing the environment Air quality has worsened in many areas, especially southern Asia and India.

Loss of Biodiversity Loss of biodiversity is happening at a rapid rate. Biodiversity - term used to indicate the total diversity of life on earth (or a given area). As species go extinct, the value that wildlife provides us with is lost. Example: medicines, food, ecosystem stability, intrinsic value

Signs of Hope Progress has been made on many fronts. Population has stabilized in most industrialized countries. Incidence of life-threatening diseases has been reduced in most countries. Deforestation has slowed and habitat protection has increased in some areas. Progress is being made in transition to renewable energy sources. Democracy is spreading, which allows decision making by local people who know the land rather than by a centralized bureaucracy.