Carbon FootprintWhat is it and why is it so complicated?

by Arlaine Freeman and Sabrina S. Fu

Carbon Footprint

Just as we leave footprints in the sand as we walk along the beach, we leave a carbon footprint as we live on the Earth.

What is a carbon footprint?

“Carbon Footprint” refers to the effect of human activities on our planet, measured in terms of how we directly and indirectly affect greenhouse gas output.

To understand what this means, we must first understand what greenhouse gases are.

Greenhouse Gases

“Greenhouse Gases” are gases that retain heat.

They are essential to life on Earth, but as with all things, too much becomes a problem.

Greenhouse Gases

The three most abundant greenhouse gases in our atmosphere are

•Water (H2O)

•Carbon dioxide (CO2)

•Methane (CH4)

Water (H20)

Water is part of the water cycle and thus cycles in between the Earth and its atmosphere.

The water content in our atmosphere is controlled by temperature, which is controlled by the other greenhouse gases.

So let’s look at the other two major greenhouse gases - carbon dioxide and methane.

Carbon Dioxide (CO2)

Natural Sources of Carbon Dioxide (CO2)•Aerobic respiration •Forest fires

Human Sources of Carbon Dioxide (CO2)•Burning fossil fuel (for transportation, electricity, farming, etc.)

Methane (CH4)

Natural Sources of Methane (CH4)•Anaerobic decomposition

Human Sources of Methane (CH4)•Raising cattle •Growing rice •Landfills •Coal mining

Sinks for Methane and Carbon Dioxide

As with all things in nature, there are “sinks,” or ways to recycle each molecule.

Methane in our atmosphere is oxidized to carbon dioxide.

Carbon dioxide is used by land and water plants, so both forests and oceans are considered carbon “sinks”.

Basis for Our Carbon Footprint

Our main energy sources are based upon fossil fuel, and we use a lot of fuel.

•We clear lands to obtain fuel (coal, oil, natural gas and wood)

•We use land to grow fuel

•We clear land for homes, roads, stores and factories

•We consume a lot of goods (obtaining, producing, packaging and disposing of these goods uses fossil fuel)

Some Implications of Our Present Lifestyle

•Clearing LandClearing land typically leads to deforestation, which leads to less photosynthesis by plants and hence more carbon dioxide in our atmosphere.

•TrashWhen the goods we use become trash, they produce greenhouse gases. Trash decomposition in landfills produces methane. The average American produces 4.6 pounds of trash per day or 1,600 pounds of trash per year.This indicates that we buy a lot of things for which we have little use.

How Did We End Up Being Consumers of Throw-Away Goods?

•The end of World War II in America signaled an extended period of peace and prosperity

•Spending was viewed as a way to keep the country on the right track through innovation and employment

•It was assumed that there were few negative consequences of using fossil fuel to process “infinite” resources

How Did We End Up Being Consumers of Throw-Away Goods?

Marketing, Advertising and Manufacturing

•The public was manipulated by marketing and advertising that appeared in newspapers and on billboards, radios and television

•Manufacturers re-evaluated their role in driving increased sales through the production of cheaper, less durable goods

Footprint in Everything We Do

There is a footprint in everything that we do.

•Everything we buy and use creates a carbon footprint.

•Everything we eat that uses fossil fuel to be grown, processed, packaged or transported also has a carbon footprint.

Difficulties in Calculating Carbon Footprint

How large our carbon footprint is depends upon

•What, where and how much we buy •What we eat and where the food comes from •How the food we eat is grown •What we choose to do with our land (for example, plant trees or deforest) •How we get ourselves from A to B each day •How much electricity we use and how we obtain our electricity (for example, coal-power versus wind power) •How we heat our homes (natural gas, corn pellets, wood, solar) •How much we recycle and reuse relative to how much we buy (e.g. how much trash we generate)

Calculating Carbon Footprint

Although there are carbon calculators available, none take into account all the ways that each of us affects our carbon footprint.

Rather than giving you a number, we hope that you can reduce your footprint by taking a few important steps...

Changing Behavior to

Reduce: The first and best way is to reduce! •Reduce personal consumption, car use, indoor heating/cooling•Grow your food (a great way to reduce carbon dioxide emissions)

Reuse: The second best way is to reuse items•Donate used items to thrift stores; reuse items, such as bags

Recycle: The most promoted and common•Many items can be recycled; check with your county •Uses less energy than to mine raw materials

Solutions and Connections

Reduce, Reuse and Recycle to minimize your carbon footprint!

To learn more and to test your knowledge in our Carbon Footprint Quiz, visit http://www.umuc.edu/gogreen

This project was created by students at University of Maryland University Collegeand supported by a People, Planet and Prosperity Grant from the U.S. Environmental Protection Agency.