1. Human Activity

2. Greenhouse Effect These gases keep heat from escaping back into space
Our earth is kept warm by certain gases in the atmosphere (carbon dioxide, for example).
These gases keep heat from escaping back into space
The greenhouse effect is a GOOD thing – it keeps the planet warm enough to support life

3. Greenhouse Effect
Note the atmosphere bouncing heat BACK TOWARDS earth – just like a greenhouse
Much of the radiation is prevented from escaping back to space

4. Greenhouse Gases
keep heat trapped in (contribute to the greenhouse effect) – this is what the heat bounces off of in the atmosphere
Includes water vapor, carbon dioxide, methane, nitrous oxide, and ozone

5. Global Warming – the bad part
Certain human activities add to the levels these naturally occurring greenhouse gases (burning fossil fuels, for example)
The theory is that greenhouse gases are rising at an alarming rate, and trapping MORE energy – making the earth warmer

6. Human Population Growth
Can impact biosphere in two significant ways:
Resource depletion (water, fossil fuels, food, habitat depletion)
Pollution (air, land, water)

7. Pesticides/Herbicides
Chemicals that kill pests and unwanted plants
The problem is that they don’t go away for a long time
This means they accumulate in groundwater

8. Biomagnification
The concentration of pollutant is multiplied as it passes up the food chain
This is because the herring eats many zooplankton
The porpoise eats many herring, etc
The top level consumers end up with the highest concentration of pollutant

9. Acid Rain
Nitrogen and sulfur emissions (from human activity) enter the atmosphere
They collect with water vapor and come down as acid rain
This kills plants (and destroys the Statue of Liberty!)