1. How Are Our Ecological Footprints Affecting Earth?

2. Quality of life and the environment
Humans use wood, fossil fuels, the sun, wind, atomic energy, and Earth’s heat to supply ourselves with energy.
We live in buildings and cities and use computers, robotics, and electronics to perform work.
Life spans are longer than ever before, infant mortality is decreasing, and more and more diseases are being cured.
Population growth rate has slowed and education is on the rise.
Humans are able to communicate extraordinarily easily and effectively and information is more accessible than ever before.

3. Humans and Environmentalism
The Federal Water Pollution Control Act was passed in ….
1948
It was the first major U.S. law to address water pollution.
It was amended heavily in 1972 and became known as the Clean Water Act
The Air Pollution Control Act was passed in ….
1955
It was the first major U.S. law to address air pollution.
It was amended in 1963 to actually control air pollution and to address emissions from cars.
It was amended again in the 1990s to address acid rain and depletion of the ozone layer.
The Endangered Species Act was passed in ….
1973

4. We are living unsustainably!
The practice of wasting, depleting, and degrading Earth’s natural capital is called environmental degradation.
The atmosphere, the ocean, and some species of plants and animals are modern “commons”.

5. Millennium Ecosystem Assessment
As of 2005, humans have overused an estimated 60% of Earth’s ecosystem services.
Most of this has occurred since 1950
Industrialized countries with high average incomes make up about 17% of the world’s populations.
US, Canada, Japan, Australia, most European countries
The remaining 83% of the population live in less-developed countries
Lower income: Many in Africa, Asia, and Latin America
Middle income: China, Brazil, Thailand, Mexico

6. Modeling Environmental Impacts
The extent of environmental degradation in the form of pollution, and waste is called an ecological footprint.
This refers to the amount of land and water needed to supply an individual or a population with renewable resources and to absorb and recycle the wastes and pollution such resource use produces.
In this model the size of the ecological footprint is proportional to the amount of renewable resources consumed.

7. Human Ecological Footprint

8. IPAT Another way to model environmental impact is the IPAT model.
Impact (I) = Population (P) x Affluence (A) x Technology (T)
Where: I is the impact of human activities
P is the population size
A is affluence
T is the beneficial and harmful effects of technologies
The IPAT model includes the environmental impact of both renewable and nonrenewable resources.