HUMAN IMPACTS ON CLIMATE NOTES

FOSSIL FUELS What are Fossil Fuels? Fossil fuel is a general term for buried combustible geologic deposits of organic materials, formed from decayed plants and animals that have been converted to crude oil, coal, natural gas, or heavy oils by exposure to heat and pressure in the earth's crust over hundreds of millions of years.

FOSSIL FUELS Examples of Fossil Fuels: Coal Oil Natural Gas

FOSSIL FUELS What happens when we burn fossil fuels? Carbon Dioxide and other pollutants are released into the air.

ACID RAIN What is acid rain? Rain that is more acidic than normal.

ACID RAIN What causes acid rain? Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants. These pollutants return to the Earth’s surface as precipitation (rain). Burning coal for the production of electricity is the major culprit.

ACID RAIN What does it do to the environment? It kills plants and animals and destroys rivers and lakes. It dissolves limestone and rocks (including buildings).

ACID RAIN-PLEASE WATCH VIDEO BELOW

OZONE LAYER What is ozone? Ozone (O3) is a highly reactive gas composed of three oxygen atoms. It is both a natural and a man-made product that occurs in the Earth's upper atmosphere (the stratosphere) and lower atmosphere (the troposphere). Depending on where it is in the atmosphere, ozone affects life on Earth in either good or bad ways.

OZONE LAYER What is the ozone layer hole? The ozone hole is not technically a “hole” where no ozone is present, but is actually a region of exceptionally depleted ozone in the stratosphere over the Antarctic that happens at the beginning of Southern Hemisphere spring (August–October).

OZONE LAYER What causes the ozone layer hole? One group of gases is particularly likely to damage the ozone layer. These gases are called CFCs, Chloro-Fluoro-Carbons. CFCs were used in some spray cans to force the contents out of the can. They are also used in refrigerators, air conditioning systems and some fire extinguishers. They are used because they are not poisonous and do not catch fire. These CFC’s can stay in the atmosphere for long periods of time. The cold of the winter condenses the CFC’s. The increased light in the spring in the southern hemisphere causes the chlorine atom to break apart and turn into ozone destroying chemical reactions.

OZONE LAYER What have we done to prevent ozone destruction? Most countries have stopped using CFC’s

OZONE LAYER Why do we need the ozone layer? What does it protect us from? The ozone layer is like a sunscreen, and a thinning of it would mean that more ultra-violet rays would be reaching us. Too many UV rays would cause more sunburn, and because sunburn causes skin cancer, this too would increase deaths. These UV rays are also dangerous for our eyes and could cause an increase in people becoming blind. That is why sunscreen and sunglasses are very important.

OZONE LAYER Can we live without the ozone layer? No!

OZONE LAYER When is ozone bad? Ozone found between 19 and 30 kilometers high (stratosphere) in the atmosphere is one of the reasons why we are alive on Earth. But when the gas ozone is found lower down where we can breathe it in, it becomes very dangerous for our health. This ozone is caused by a reaction between air pollution and sunlight and can cause modern-day smog. Ozone in stratosphere=good Ozone in troposphere=bad

CLIMATE CHANGE/GLOBAL WARMING Please use your personal knowledge to answer the following questions on your note page: Describe what is happening to cause the climate to change. What is the relationship between carbon dioxide and the greenhouse effect? What are the greenhouse gasses? (water vapor, carbon dioxide, methane, nitrous oxide, and ozone) What are some ways that we can cut back on the amount of carbon dioxide in our atmosphere? What is the relationship between carbon dioxide and global climate change?