The combustion of fossil fuels releases carbon dioxide (a major “greenhouse gas”) into the atmosphere, and most climate scientists believe that the buildup of those gases is the primary cause of the global warming that has occurred in recent decades. Because the effects of carbon dioxide (CO2) result in more than just rising temperatures, scientists prefer the phrase “climate change,” which helps convey that other changes are taking place as well.
At present, the United States emits approximately one-fifth of the world’s greenhouse gases, and the nation’s CO2 emissions are projected to rise from about 5.9 billion metric tons in 2006 to 6.4 billion metric tons in 2030.
Climate change will have a range of impacts. In some parts of the world, it could bring positive effects such as longer growing seasons and milder winters. Unfortunately, however, it is likely to bring harmful effects to a much higher percentage of the world’s population. And many of the world’s poorest people, who lack the resources to respond to the impacts of climate change, are likely to suffer the most. For example, Bangladesh, one of the world’s most impoverished nations, is projected to lose 17.5% of its land if sea level rises about 1 meter (39 inches), displacing millions of people. Several islands in the South Pacific and Indian oceans may disappear entirely.
These projections are based on science. Temperature readings from around the globe show a relatively rapid increase in surface temperature during the past century, with an especially pronounced warming trend during the past 30 years. In addition, CO2 concentration in the atmosphere has risen about 40% since the beginning of the industrial revolution.
At present, the United States emits approximately one-fifth of the world’s greenhouse gases, and the nation’s CO2 emissions are projected to rise from about 5.9 billion metric tons in 2006 to 6.4 billion metric tons in 2030, assuming no changes to the control of carbon emissions. However, such controls may indeed be coming if pending energy legislation results in the adoption of a cap and trade system or a carbon tax to control CO2 emissions in the United States.
Of course climate change is not just a national concern. Worldwide, CO2 emissions are projected to increase substantially, primarily as a result of increased development in China and India. Therefore, future decisions about whether and how to limit greenhouse gas emissions will affect us all.