The Environment & Human Impact

Humans and the Environment

• 10,000 years ago, there were only about 5 million people on Earth.

• The development of dependable food supplies, sanitation, and medical care have allowed the population to grow to more than 6 billion, and it keeps rising!

• Learning about our planet can help us care for the environment and can help us ensure that it will continue to support us and other species on Earth

Resources

• Earth’s resources are described as renewable or nonrenewable

• Renewable resources are natural resources that can be replaced at the same rate at which they are consumed– Ex: Wind energy & solar

energy

Resources

• Nonrenewable resources are resources that form at a rate that is much slower than the rate at which they are consumed– Ex: Coal and Oil– These resources are

fossil fuels that are formed from the remains of organisms that lived millions of years ago

The Environment and Health

• Our health and quality of life are affected by the state of the environment

• Pollution and habitat destruction destroy the resources we need to live, such as the air we breathe, the water we drink, and the food we eat

Air Pollution

• Most air pollution is caused by human activities

• The burning of fossil fuels releases pollutants into the atmosphere (carbon dioxide, sulfur dioxide, and nitrogen oxides)

• Air pollution causes respiratory problems for people, results in acid rain, damages the ozone layer, and may affect global temperature

Acid Rain

• Acid rain is precipitation that has an unusually high concentration of pollutants

• It can damage forests and lakes

The Greenhouse Effect

• The greenhouse effect is the natural and necessary warming of the Earth that happens when greenhouse gases in the air (like CO2 and water vapor) absorb and reradiate heat

Global Warming• The burning of fossil fuels has INCREASED the

amount of greenhouse gases in the atmosphere, which may be causing the Earth to become TOO warm

MISUNDERSTANDING ALERT!

• Greenhouse effect vs. global warming!• What’s the difference?• How are they related?

Water Pollution

• Water pollution can come from fertilizers, pesticides, industrial waste, oil runoff from roads, and landfills

What can we do?