Scientists believe greenhouse gases play a major role in climate change, affecting the Earth’s land and ocean ecosystems. According to the Environmental Protection Agency (EPA), the U.S. produced about 6,822 million metric tons of greenhouse gases in 2010. A recent report released by Reuters stated the worldwide greenhouse gas emissions rose 3.2 percent in 2011 to 31.6 billion metric tons. So, what are the ramifications and solutions to the problem?
What are Greenhouse Gases?
Greenhouse gases can be described as various natural and manmade gases in the atmosphere that create sort of a “blanket” on the Earth. These gases allow sunlight to enter the atmosphere but restrict how much radiation (heat) reflects off the Earth’s surface and returns back into space. The heat remains trapped in the Earth’s atmosphere and consequently raises the overall temperature.
The Top Four Greenhouse Gases
There are many types of greenhouse gases but according to the U.S. Energy Information Administration, the top four types of greenhouse gas include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and fluorinated gases.
Carbon dioxide is by far the most abundant greenhouse gas present in the atmosphere, making up about 84 percent of the total. While carbon dioxide is a required component of photosynthesis (plant growth process), the amount of the gas currently in the atmosphere far outweighs the natural need for it. The excess CO2 can remain in the Earth’s atmosphere for thousands of years. Sources of carbon dioxide gas include burning of fossil fuels (i.e., coal, gasoline) and other industrial processes.
Methane gas makes up about 10 percent of all greenhouse gas in the atmosphere, followed by nitrous oxide at about four percent. These gases are emitted when fossil fuels are burned. Other sources of these greenhouse gases include decaying garbage at landfills and from agricultural applications, such as fertilizers. Methane gas has a relatively short shelf life of 10 to 12 years in the Earth’s atmosphere.
Fluorinated gases occupy about two percent of all greenhouse gases in the atmosphere. These gases are emitted from various industrial processes. Fluorinated gases are exceptionally good at trapping heat, so although these gases are not found in very high concentrations in nature, they are particularly harmful when it comes to climate change.
Do Landfills Contribute to Climate Change?
By far the biggest contributor to greenhouse gases is the energy sector (i.e., power plants, industry), but landfills do contribute to the greenhouse effect as well, albeit on a much smaller scale. The primary gas emitted by landfills is methane, which is released during the trash decomposition process. However, the National Climatic Data Center states the atmospheric concentration of methane “has not risen much” since 1990. So, that’s good news.
How Modern Landfills Improve the Greenhouse Effect
Modern landfills are far more innovative than most people think; they’re not just holes in the ground filled with trash anymore. Hundreds of landfills across the U.S. are turning to new technology aimed at converting trash into energy. One such method is capturing the methane released naturally by decaying garbage and turning it into a usable energy source.
Utilizing methane as an alternative energy source helps the environment in several ways:
- It reduces the need for energy derived from “dirty” sources, such as coal power plants, which produce greenhouse gas byproducts.
- It also directly affects how much methane gas is released into the atmosphere, so it plays an important role in reducing the environmental impact of this particular gas.
Other innovative landfills are burning trash to produce electricity. The process reduces the amount of trash that actually reaches the landfill and subsequently the amount of greenhouse gases released. The gases produced during the trash incineration process are filtered to remove elements potentially harmful to the environment.
The greenhouse effect is certainly a work in progress, but modern landfills and clean-burning technology are helping to improve the situation.
Image Courtesy of NASA / Goddard Space Flight Center