• About three-quarters of the CO2 emissions caused by human activity during the past 20 years comes from burning fossil fuels. The rest is predominantly due to land-use change, especially deforestation.
• The U.S. presently emits more greenhouse gases per person than any other country, accounting for roughly 25% of global emissions, with only 4.6% of the world’s population.
• The average U.S. citizen emits roughly 6.6 tons of greenhouse gases each year.
• Industry contributes the most to sector-wide GHG emissions each year and electricity is the leading cause of industrial emissions.
• U.S. carbon dioxide emissions have grown by more than 18% since 1990 and the Department of Energy now projects that they will increase by another 37% by 2030. (Pew Center)

• Continuation of historical trends in greenhouse gas emissions will result in additional warming over the 21st century, with current projections of a global increase of 2.5ºF to 10.4ºF by 2100, with warming in the U.S. expected to be even higher. For a comparison, global temperatures during the last ice age (about 20,000 years ago) were only 9°F cooler than today, but that was enough to allow massive ice sheets to reach as far south as the Great Lakes and New York City.
• Rising air temperatures have already resulted in the retreat of mountain glaciers, reduced snow-cover, earlier snow melt, rising sea level, and the movement north of some species habitat.
• According to the EPA, a two-foot rise in sea level would eliminate 17-43% of U.S. wetlands (with more than half the loss taking place in Louisiana). Furthermore, it would eliminate approximately 10,000 square miles of land, an area equal to the combined size of Massachusetts and Delaware.
• Developing nations, who are less equipped to handle the impacts of climate change, will be among the most effected by the adverse impacts of climate change, including decreased access to water sources, further reductions in viable farmland and disease outbreaks.

Electricity generation is responsible for 33% of greenhouse gas emissions and the demand for electricity is growing rapidly. As of the year 2000, in the United States, generation of electricity was responsible for 33% of total GHG emissions; transportation 27%, industry 19%, agriculture 8%, commercial establishments 7%, and residences 5%. The world will consume 75% more electricity in 2020 than it does today––and that demand will triple by 2050, according to the World Energy Council.

CO 2 emissions from transportation also make a significant contribution to the Green House Gas emissions released today. According to the most recent data, 14% of the world’s human activity-related emissions come from transportation. And, North America is the per capita leader of CO 2 emissions resulting from gas and oil combustion. It is undeniable that transportation is essential to our way of life, and emissions resulting from the transportation sector are still on the rise. According to the EPA, this trend may be attributed to two related causes : the average fuel economy of passenger vehicles in the U.S. has declined, while the number of miles driven by Americans continues to increase. The average passenger vehicle, driven 12,500 miles per year emits about 11,450 pounds of CO 2 per year.

For a brief overview of international and regional greenhouse gas policy and initiatives visit The Pew Center for Global Climate Change.