Greenhouse Gases - Sources and Effect on Climate Changes

Greenhouse gases and climate change

What are greenhouse gases?

 The US EPA says that the key greenhouse gases of concern are:

Of these, carbon dioxide (CO2) is the primary greenhouse gas pollutant, accounting for nearly three-quarters of global greenhouse gas emissions and 84% of U.S. greenhouse gas emissions. The EPA maintains that carbon pollution leads to long-lasting changes in our climate, such as:

Where do these greenhouse gases come from?

Greenhouse gas emission sourcesAccording to the US EPA, the primary sources of greenhouse gas emissions in the United States are:

Lesser sources

Greenhouse Gas Emissions and Trends

Since 1990, U.S. greenhouse gas emissions have increased by about 5%. From year to year, emissions can rise and fall due to changes in the economy (when there is a recession, people buy and use less), the price of fuel (when oil and gas are expensive, people cut out vacations and reduce driving), and other factors. In 2012, U.S. greenhouse gas emissions decreased compared to 2011 levels. The EPA believes this decrease was primarily due to a decrease in the carbon intensity of fuels consumed to generate electricity due to a decrease in coal consumption, with increased natural gas consumption and a significant increase in hydropower used. Natural gas burns much more cleanly than other fossil fuels and of course, hydroelectric power plants produce only negligible amounts of greenhouse gases.

Additionally, relatively mild winter conditions, especially in the South Atlantic Region of the United States where electricity is used in heatingmany homes, resulted in an overall decrease in electricity demand in most sectors.


  1. US EPA - Sources of Greenhouse Gas Emissions

This page was updated on 30-Mar-2016