Pollution

Air Pollution

What is air pollution?

• …air that contains harmful substances at unhealthy levels.

Where does air pollution come from?

1) Burning fossil fuels

* cars, factories

2) Thermal Inversion

* occurs due to heating

3) Natural events

Other ways to reduce pollution from cars…

1) Drive less

2) Car pool

3) More fuel efficient cars

4) More alternative fuel cars (ethanol, hydrogen, electric)

Smog (“smoke & fog”)

…air pollution in cities that reduces visibility

1) Caused by a chem. rxn with: sunlight & pollutants (from cars & industries mostly)

2) Cities in warmer regions are more likely to have smog

Acid Rain

What is acid rain?

…precipitation with a pH below 5.6

What causes acid rain?

1) Gases in the air chemically reacts with the water vapor or precipitation forming an acid.

***the gases come from burning fossil fuels

-gases like nitrogen oxide, sulfur dioxide, carbon monoxide, etc…

How does acid rain affect ecosystems?

1) Makes bodies of water more acidic.

* affects the organisms in the water.

2) Changes the pH of soil, causes problems for the plants.

Other problems caused by acid rain

Property damage:

*damages paint finishes (cars)

*erodes structures

*corrodes metals

Controlling acid rain

1) Eliminate / reduce pollution, mostly emissions from cars, factories, power plants.

2) International cooperation is needed

The Greenhouse Effect

What is the Greenhouse Effect?

…a process where heat from the sun is trapped at the surface of Earth by gases in the atmosphere

What causes the Greenhouse Effect?

…the large amount of “greenhouse gases” put into the atmosphere by burning fossil fuels and other activities.

What are the common “greenhouse gases”?

• CO2

• Water vapor

• CFC’s

• Methane

• Nitrous oxide

How has the temperature of Earth changed over time?

As CO2 levels have increased greatly over the last 100+ years, so has the average temperature on Earth.

Over thousands of years the pattern has been the same, increasing CO2 has caused in increase in temperature.

What changes may result from the Greenhouse Effect?

1) Hurricanes – more & stronger hurricanes due to increasing ocean temperatures.

2) Drought & flooding – more rain in areas that used to get very little & less rain in other areas.

3) Agriculture – areas that used for farming may change making those areas less useful.

4) Coastal flooding – polar ice melting, causes ocean levels to rise, flooding lower lying areas on the coast.

How can the Greenhouse Effect be reduced?

Reduce the amount of “greenhouse gases” in the atmosphere!

- less fossil fuel use

- reduce CFC’s

- stop deforestation

- plant more trees

Before & After Pictures of Glaciers

The Ozone Problem

What is ozone?

…O3

…found in the stratosphere

…protects Earth from ultraviolet (UV) radiation

Damage to the Ozone

1) CFC’s – (chlorofluorocarbons)

* found in refrigerants, aerosol propellants, making styrofoam

* new laws regulating them, so CFC’s are not really used anymore.

* CFC’s break up Ozone in the stratosphere

2) Ozone hole / thinning …thinning at the poles, by as much as 98%.

*due to the damage from CFC’s

The Effects of the Damage to the Ozone.

1) Increase in skin cancers

What happens when you ignore skin cancer…

2) Increase in cataracts (eye problems)

Sight without & with a cataract

3) Kill plankton at the surface of water & disrupt food webs

4) Damages animals & plants – sensitive to changes in radiation (amphibians especially)

Preventing Ozone damage

1) CFC’s reduced / eliminated – The Montreal Protocol was signed by most industrialized countries, eliminated the production of CFC’s.

Problems with CFC’s

We have slowed the depletion of Ozone.

CFC’s stay in the stratosphere for a long time (20+ years), so ozone released long ago is still destroying ozone.