Day 1- Human Impact on The Environment

Essential Question:

How are humans causing changes to the natural state of the Earth?

Population Growth and Environmental Impact

Human population growth pressures physical environment, need for space and raw materials is going up

People in developed nations have a greater demand for raw materials and generally more wasteful than underdeveloped countries

Human impacts on the environment

Global warming• Use of machinery by humans seems to be increasing atmospheric CO2 levels. Carbon dioxide prevents heat energy from escaping, causes slight world wide temperature increases

Rising water temperatures causes coral bleaching

Human impacts on the environment

Deforestation• Caused by demand for wood products, need for space, farmland, housing, roads • Deforestation causes habitat fragmentation• Animals and plants are forced into confined areas

Human impacts on the environment

Ozone depletion• Caused by aerosol chemicals called chloroflurocarbons (CFCs) commonly used as coolants

• Escape into atmosphere, reacts with ozone (O3, a protective atmospheric layer)

• UV rays penetrate atmosphere and cause harm to many organisms

Human impacts on the environment

Fishing activities• Demand for fish and shellfish

• Fishing is harmful to the environment in many ways

• Bycatch, gear losses, trawling scours sea bottom

Human impacts on the environment

Invasive species• Typically introduced by people accidentally or intentionally

• Can cause problems if no natural enemies are present

• Islands and other confined ecosystems are at riskCane toad was introduced to Australia to control cane beetles, pest insects that destroy sugar cane crops

Toads did not control cane beetles, instead they took over and cane toads are unusually hardy

Human impacts on the environment

Exotic pet trade• Capture and sell wild animals from exotic locations

• Wealthy buyers and collectors desire obscure animals

• Animals removed from their habitat causes an imbalance in ecosystem

Responding To The Essential Question:

• How are humans causing changes to the natural state of the Earth?

• In 1 paragraph describe the impact humans are causing on the environment. Use at least 3 ideas presented in today's notes and describe them.