Environmental Science: Earth as a Living Planet Chapter 1

Major Themes of Environmental Science World Population In A.D. 1- 100 Million people In 1960- 3 Billion people Today- 6.7 Billion people Projected: 10 Billion by 2040 It took human population almost 2000 years to get to 3 billion, only 40+ years to add 3 billion more

Problem? The Earth has not grown any larger and the abundance of its resources has not increased Can the Earth SUSTAIN all these people? What is the maximum number of people that Earth can support? (remember: Easter Island)

World Population How many people the Earth can sustain depends on science and values and is also a question about people and nature. What quality of life are people willing to accept? The poorer that quality, the greater the number of people that can be squeezed onto the Earth’s surface

Human Population Growth John Eli Miller Family Of 7 children born to John Miller, 5 survived him Of 63 grandchildren, 61 survived him Of the 341 great-grandchildren (born to 55 married grandchildren- an average of slightly more than 6 children per parent- 338 survived him)

John Eli Miller Family

Modern Population Explosion Major factors in population: Supply of Food Supply of Clothing Shelter Decreased death rates (medical improvement) As a result, the human population has increased greatly, threatening the environment

World Population

Consequences of Rapid Population Growth FAMINE is one of the things that happen when a human population exceeds its environmental resources In 1970’s, following a drought in the Sahel Region, 500,000 Africans starved to death and several million more were permanently affected by malnutrition

FAMINE In 1980’s - In one year during that period, as many as 22 African nations suffered catastrophic food shortages and 150 million Africans faced starvation There is a continuing food crisis in Southern Africa (Malawi, Zambia and Zimbabwe)

Reasons for Famine? Drought Size of Population affected by drought- competing for resources Changing climate- partly because of human activities Poor farming practices- erosion of soil Deforestation

We are forced to confront a choice Which is more important, the survival of people alive today or conservation of the environment, on which future food production and human life depend?

An Urban World With economic development, comes URBANIZATION Urbanization = people move from farms to cities and then perhaps to suburbs Cities and towns increase in size Cities are commonly located near rivers and coastlines

Destroying Wetlands Urban sprawl often overtakes good agricultural land of river floodplains as well as coastal wetlands, which are important habitats for many rare and endangered species. As urban areas expand, wetlands are filled in, forests are cut, and soils covered over with pavement and buildings

Urban Sprawl In developed countries, 75% of the population live in urban areas, with 25% in rural areas In developing countries, only 40% of the people are city dwellers It is estimated that by 2025 almost two-thirds of the population (5 billion people) will live in cities

Largest Cities In 1999, Tokyo, Japan was the world’s largest city In 2015, Tokyo will still be the world’s largest city with an estimated population of 28.9 million Megacities- at least 8 million people Increased from 2 (NY and LA) to 23 in 1995 Largest Cities

Megacities Most Megacities- 17- are in the developing world It is estimated that by 2015- the world will have 36 Megacities, 23 of them will be in Asia Environmental issues have always focused on non-urban issues (wildlife, etc.) but needs to shift to urban issues

Sustainability What is sustainability? Refers to resources and their environment Sustainable Resource Harvest- the same quantity of that resource can be harvested each year for an unlimited or specified length of time without decreasing the ability of that resource to continue to produce the same harvest level

Sustainable Ecosystem An ecosystem that is still able to maintain its essential functions and properties even though we are harvesting one of its resources

Sustainable Development A society can continue to develop its economy and social interactions and also maintain its environment for an indefinite time

Carrying Capacity Related to sustainability The maximum number of individuals of a species that can be sustained by an environment to sustain that same amount in the future Question: What is the maximum number of people that the Earth can sustain?

People and Nature People and nature are intimately integrated- each affects the other. We depend on nature for our lives We depend on nature for beauty and recreation We affect nature

Gaia Hypothesis Originated by British chemist James Lovelock and American biologist Lynn Margulis Proposes that the environment at a global level has been profoundly changed by life over the history of life on Earth and that these changes have tended to improve the chances for the continuation of life.

Placing a Value on the Environment How do we place a value on any aspect of our environment? The value of the environment is based on eight justifications: aesthetic, creative, recreational, inspirational, moral, cultural, ecological, and utilitarian

Utilitarian Justification Sees some aspect of the environment as valuable because it benefits individuals economically or is directly necessary to human survival Example: Mangrove Swamps provide shrimp that are the basis of the livelihood of the fisherman

Ecological Justification An ecosystem is necessary for the survival of some species of interest to us, or that the system itself provides some benefit. Example: Mangrove Swamps provide habitat for marine fish, and although we do not eat Mangrove Trees, we may eat the fish that depend on them.

Aesthetic Justification Our appreciation of the beauty of nature Example: When people grieve following the death of a loved one, they typically seek out places with grass, trees and flowers and thus we decorate our graveyards

Recreational Justification People use wilderness for recreation Example: White water rafting, fishing, and hiking

Inspirational Justification Conservation of nature can be based on its benefits to the human spirit Example: Religious Retreats

Creative Justification Nature is an aid to human creativity Example: Artists, poets and others find a source of their creativity in their contact with nature

Moral Justification Has to do with the belief that various aspects of the environment have a right to exist and that it is our moral obligation to allow them to continue or help them to persist. Example: Species have a moral right to exist

Do Rocks Have Rights? The United Nations General Assembly World Charter for Nature, signed in 1982, states that species have a moral right to exist.

The Big Question DO we have a moral obligation to future generations? to leave the environment in good condition for our descendants, OR Are we at liberty to use environmental resources to the point of depletion within our own lifetime?