Carbon Footprint: Intro to Greenhouse Gases

We have received a request to address “Carbon Footprints,” and the responsibility of reducing our impact on the world as much as possible. This is actually quite a complicated subject, so I’ll rely on a lot of work that has already been done, and use a series of posts to guide the readers through the process.

This National Geographic article, What Is a Carbon Footprint and How to Reduce It?, effectively describes what a Carbon Footprint is: (emphasis added)

Everything you do has an impact — positive or negative — on the environment. That’s the concept behind your carbon footprint, which is one method of measuring the environmental effect of your lifestyle. A carbon footprint, measured in tons, indicates the amount of carbon dioxide and other greenhouse gases that are produced as a result of your daily activities. You can reduce your footprint by changing the way you live your life. Even seemingly tiny changes can make a significant difference.

What are the greenhouse gases in question?

• Carbon Dioxide (CO2) – emitted into the atmosphere when fossil fuels, solid waste, trees and wood products are burned and as a result of some other chemical reactions. The CO2 can also be removed from the air when absorbed by plants as part of their natural processes. (Thus, the importance of trees in reducing some greenhouse emissions.)
• Methane (CH4) – emitted during the production and transport of coal, natural gas, and oil as well as from livestock, agricultural processes, and the decay of organic waste.
• Nitrous Oxide (N2O) – emitted during agricultural and industrial activities, and during the combustion of fossil fuels and waste.
• Flourinated Gases – a range of synthetic gasses that are emitted from a variety of processes. They used to be found in many aerosol sprays.

Some date from the 2012 U.S. Greenhouse Gas Inventory Report

• In 2010, U.S. greenhouse gas emissions totaled 6,821.8 million metric tons CO2 Eq.
• U.S. emissions rose by 3.2% from 2009 to 2010. This increase was primarily due to an increase in economic output resulting in an increase in energy consumption across all sectors and much warmer summer conditions resulting in an increase in electricity demand for air conditioning.
• Since 1990, U.S. greenhouse gas emissions have increased by 10.5%.

Reference: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2009, USEPA #430-R-11-005

This figure sows the contribution of all four types of greenhouse gases to the total U.S. Emissions.

• Carbon Dioxide (CO2) represented approximately 83 percent of total greenhouse gas emissions, and the primary source of these emissions was the combustion of fossil fuels.
• Methane Emissions come in second with 10 percent of U.S. greenhouse gas emissions in 2009. These emissions  resulted primarily from natural gas systems, enteric fermentation in livestock and decomposition of wastes in landfills.

Where do these gases come from?

To understand more clearly where these emissions originated, the EPA, also presents emissions categorized with common economic terms.

According to the graph on the left, the biggest portion of  greenhouse gas emissions in the U.S. comes from the production of electricity. Since electricity is consumed by the other economic sectors, the emissions from electricity are then distributed among those sectors (right), showing that the industrial sector accounts for the largest share of U.S. greenhouse gas emissions at 29%. Transportation comes in at a close second with 27%.

For more information to hold you over until the next post, check out National Geographic’s information;

How Do I Measure a Carbon Footprint?
How to Figure Out Your Carbon Footprint
A Low Carbon Footprint
What Does Reducing Your Carbon Footprint Mean?
Carbon Footprints & Ideas on How to Minimize Them

Advertisement