Pollution and

Biogeochemical Cycles

Why should you careabout the Earth?

Pick a partner that sits near you.

Write two or three reasons.

Reasons to care

1. We have just one planet.

2. We have limited

resources.

Reasons to care

3. Environmental disasters have killed millions of animals

Exxon-Valdez - the oil spill killed about 250,000 sea birds, 2,800 sea otters, 250 bald eagles and possibly 22 killer whales.

Gulf war - poisoned waters killed 20,000 seabirds and had caused severe damage to local marine flora and fauna. The fires in the oil wells caused immense amounts of soot and toxic fumes to enter the atmosphere.

Reasons to care

4. Environmental disasters have killed people to like…

15,000+ in India from Union Carbide gas leak

Chernobyl - Russian nuclear powerplant explosion 30,000+ killed

Italian chemical plant explosion

London smog Kills 12,000+

Reasons to care

5. Pollution affects us all- our land, air and water

• The warming of the Earth’s atmosphere is as result of increase in green house gases such as CO2 ,

methane, CFCs, nitrogen oxides and ozone – Warming can occur through natural

causes but is being increased by humans activities.

6. Global Warming (Greenhouse effect)

Environmental Effects• Altered rain patterns• Glaciers and ice caps melting• Rising Sea levels• Permafrost melting• Increase in Temperature of Ocean

– Stronger storms

• Increase in Temperature of many parts of Earth as well as cooling in others.– Warming in North America and Eurasia– Cooling in parts of southeastern U.S.

Why does pollution in one area affect

others?All the bigeochemical cycles –

Nitrogen, Water, Carbon & Oxygen are connected.

• Biogeochemical cycles - elements, chemical compounds, and other matter are passed from one organism to another and from one part of the biosphere(earth) to another.

– Matter can recycle because biological systems do not use up matter, they transform it (known as the law of conservation).

– Matter is assembled into living tissue or passed out of the body as waste products.

• Four elements (oxygen, hydrogen, carbon, and nitrogen) are the most common in organisms but must be in a chemical form for cells to take up.

Nitrogen Cycle

Why do we need nitrogen?

-Protein and DNA/RNA

What would happen if weremoved one part of the Nitrogen cycle?

-The cycle would be broken.

What happens when we break part of the cycle?

-Organisms cannot exist; they must adapt or die.

Stages of Nitrogen Cycle

1. Ammonification – produces ammonia by bacteria (Nitrogen fixation)

2. Nitrification – ammonia is converted to nitrate

3. Assimilation – absorption and incorporation of nitrogen into plant and animal compounds.

4. Denitrification – nitrate converted to nitrogen gas.

Carbon & Oxygen CyclePhotosynthesis

Cellular Respiration

Carbon and oxygen are cycled back in forth between photosynthesis in plants and cellular respiration in almost all organisms

How is Carbon cycled back through the system?1. Respiration2. Combustion – burning wood or fossil fuels3. Erosion – sea or waves eroding limestone

Carbon & Oxygen CycleWhich part of this cycle has changed drastically over the last 200 years?

- Combustion

Why has combustion increased?

-The industrial revolution

How has increased combustion affected the Earth?

-caused Global Warming

What has global warming caused?

-polar ice caps melting, flooding, climate change

Looking at the cycle how could we counteract combustion?

-Increasing photosynthesis can counteract combustion

The Water CycleRemember water is H20

• Evaporation - water changes from a liquid form to an atmospheric gas.

• Transpiration - Water evaporates from the leaves of plants.

• Water vapor condenses into tiny droplets that form clouds.

• The water returns to Earth’s surface in the form of precipitation (rain).

• Water enters streams or seeps into soil where it enters plants through their roots.

Water CycleWhat happens to pollutants in the water?

-some are incorporated into the tissue of organisms.

Who is most harmed by the pollutantsor toxins in the water?

-Organisms at the top of the food chain.

Why do organisms at the top get the most toxins?

-Biological magnification

Today’s activity1. Biogeochemical Cycle Jigsaw

Activity.1. Use your books or phone to fill out

information.

2. Must do all 4 cycles.