Environmental Science

1. Environmental Science

2. Environment – everything that affects a living organism. • Ecology – biological science that studies the relationships between living organism and their environment • Environmental Science – an interdisciplinary study of how the earth works, how we are affecting the earth’s life support systems (environment), and how to deal with the environmental problems we face.

3. Goal to achieve • Environmentally sustainable society – tries to achieve two goals. • First, it satisfies the basic needs of its people (food, clean water, clean air, shelter) into the indefinite future. • Second, it does this without depleting or degrading the earth’s natural resources and thereby preventing current and future generations of humans and other species from meeting their basic needs.

4. Living sustainably – means living off natural income replenished by soils, plants, air, and water and not depleting the earth’s natural capital that supplies this income. • Protect your capital and live off the income it provides.

5. Environmental issues • Population growth • Increasing and wasteful resource use • Global climate change • Biodiversity crisis – premature extinction of plants and animals and destruction and degradation of wildlife habitats • Pollution • Poverty

8. Population Growth : J shaped curve

9. World population • 1950 – 2003 2,5 b – 6,3 b • 2028 8 b • 2050 9 b • 2100 10 – 14 b

10. Annual increase in world population today is nearly 100 million people, as the population of Mexico • 260,000 each day, 180 every minute

14. Exponential growth – quantity increases by a fixed percentage of the whole in a given time.

15. Developed countries • 1,2 billion people • US, Canada, Japan, Australia, New Zealand, Europe • These countries with 19% of the world’s population have about 85% of the world’s wealth and income, use about 88% of its natural resources, and generate 75% of its wealth and waste.

16. Developing countries • 5,1 billion people • Population growth 0,1% • Africa, Asia, Latin America • These countries with 81% of the world’s population have about 15% of the world’s wealth and income, use about 12% of its natural resources, and generate about 25% of its wealth and waste.

17. Developing countries • 97% of the projected increase in the world’s population is expected to take place in developing countries. • 1 million people are added every 4 days • Population growth 1,6% • Primary reason for rapid population growth in developing countries is the large percentage of people who are under age 15. (33% compared to 18% in developed countries in 2003)

18. Increase Resource Use : What keeps us alive • Our existence, lifestyles, and economies depend completely on the SUN and the EARTH. • Solar Capital - Energy from the sun • Natural Capital/Natural Resources – air, water, soil, wildlife, forest, rangelands, fisheries, minerals, natural purification, recycling, pest control process.

20. Resources • Anything obtained from the environment to meet human needs and wants. • Examples – food, water, shelter, goods, transportation, communication, recreation

22. Resources • Perpetual – solar energy, winds, tides, water • Renewable – fresh air, fresh water, fertile soil, plants, animals • Nonrenewable – fossil fuels (oil, natural gas, coal), metallic minerals (iron, copper, aluminium), non metallic minerals (clay, sand, phosphates)

23. Perpetual resources • Renewed continuously • Example – solar energy which can last for 6 billion years

24. Renewable resources • Can be replenished fairly rapidly (hours to several decades) through natural processes • Example – forest, grassland, wild animals, fresh water, fresh air, fertile soil

25. Sustainable yield • The highest rate at which a renewable resource can be used indefinitely without reducing its available supply.

26. Environmental degradation • When we exceed a resource’s natural replacement rate, the available supply begins to shrink • Examples – urbanization of productive land, excessive top soil erosion, deforestation, ground water depletion, overgrazing of grasslands by livestock, reduction in the earth’s forms of wildlife, pollution.

27. Tragedy of the commons • Degradation of renewable free access resources (Garrett Hardin, 1968) • Environmental degradation because of overuse of common property or free-access resources. • Such resources are owned by no one but are available to all users at little or no charge. • Examples – clean air, open ocean and fish, birds, wildlife species, publicly owned lands (such as national forests, national parks), gasses of the lower atmosphere, and space.

28. Tragedy of the commons Solution – to use free-access resources at rates well below their estimated sustainable yields or overload limits by : • Reducing Population • Regulating access • Both

29. Tragedy of the commons Solution – to convert free-access resources to private ownership. The owners have a strong incentive to protect their investment.

30. Environmental effects of poverty • Poor people deplete and degrade local forest, soil, grassland, wildlife, and water supplies for short term survival. • The poor live in areas with high levels of air and water pollution, and with the greatest risk of natural disasters • Poor people take jobs with unhealthy and unsafe working conditions at very low pay • Poor people often have many children as a form of economic security • Poor people die prematurely from preventable health problems – 9 million per year die prematurely from malnutrition, infectious diseases. Two thirds are under 5

31. Ecological footprint • The per capita ecological footprint is a measure of the biologically productive areas of the earth required : • to produce the renewable resources (such as food and wood) • supply space for infrastructure • absorb the greenhouse gas CO2 emitted from burning fossil fuels.

32. Ecological footprint • The ecological footprint of each person in developed countries is large compared to that in developing countries • In 1999, the average global ecological footprint per person was 2,3 ha.