Carbon dioxide
Carbon dioxide (CO2) is a chemical compound made up of one carbon atom and two oxygen atoms. It is a vital gas for life on Earth, as it is used by autotrophs in the process of photosynthesis to produce oxygen and complex organic compounds. However, the levels of CO2 in the atmosphere have significantly increased since the Industrial Revolution, primarily due to the burning of fossil fuels like coal, oil, and natural gas, as well as land clearing activities. This rise in CO2 is closely associated with global warming and climate change, as the gas traps solar energy in the atmosphere.
Historically, CO2 levels have fluctuated over geological time, but they remained relatively stable until the late 19th century, averaging around 280 parts per million (ppm). Recent measurements have shown a drastic increase, with levels reaching 385 ppm by 2008, and projections suggest they could rise to 1,000 ppm by the year 2100 if emissions continue unabated. Industrialized nations have been major contributors to CO2 emissions, though rapidly developing countries like China and India are also significant sources due to their heavy reliance on coal. International efforts, such as the Kyoto Protocol, have aimed to regulate emissions, but achieving substantial progress has proven challenging. In 2023, new initiatives were announced to further address CO2 reduction and mitigate its impact on climate change.
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Subject Terms
Carbon dioxide
CATEGORIES: Pollutants and toxins; atmosphere and air pollution
DEFINITION: Chemical compound in which molecules are composed of one carbon atom and two oxygen atoms
The increase of carbon dioxide in the earth’s atmosphere that has been occurring since the Industrial Revolution, if not earlier, has been linked to global warming. International efforts undertaken to limit emissions of carbon dioxide have met with varying degrees of success.
Carbon dioxide (CO2), a gas that is essential to life on earth, is generated by the burning of fossil fuels such as wood, oil, and and by the of matter. Approximately 57 percent of greenhouse gases, of which CO2 is one, come from the burning of fossil fuels. Land clearing also contributes to CO2 in the atmosphere. A large amount of CO2 is found in deposits in the floors of the earth’s oceans. When this gas is released into the atmosphere, it remains and helps to trap solar in a process that has been shown to contribute to climate change.
The amount of carbon dioxide in the atmosphere has varied over the life of the planet; the amount has been both much lower and much higher than that present during the early twenty-first century. The CO2 level in the atmosphere was relatively stable, however, from the end of the last ice age until the nineteenth century, averaging 280 parts per million (ppm). From the start of the Industrial Revolution to the middle of the twentieth century, CO2 levels grew at a steady rate, and the rate of growth increased in the latter half of the twentieth century. When measurements were first undertaken at the Mauna Loa Observatory in Hawaii in the 1950’s, the measured of CO2 was 315 ppm; by 2008 the concentration stood at 385 ppm. Some scientists estimate that the amount of CO2 in the earth’s atmosphere could be as high as 1,000 ppm by the year 2100 if emissions continue to increase unchecked. Such a level could produce global temperatures that are 5 degrees Celsius (9 degrees Fahrenheit) warmer than in the early twenty-first century, a level not seen for several million years. Even a moderate increase to 440 ppm is expected to produce a temperature increase of 3 degrees Celsius (5.4 degrees Fahrenheit).
Industrialized countries such as the United States and Germany are major producers of all greenhouse gases, especially CO2, owing to their high levels of use of fossil fuels. Some industrialized nations have turned increasingly to energy sources that produce less CO2, such as natural gas. However, industrializing nations such as India and China are also major producers of CO2, largely because they burn a great deal of coal, which produces more CO2 than other fossil fuels.
Somewhat surprisingly, the industrializing nation of Brazil is a significant producer of CO2 as the result of the clearance of massive areas of land in the Amazon basin for agriculture; this process produces CO2 as the decomposes or is burned. Other, less industrialized nations in Asia, Africa, and South America also produce CO2 as they harvest large amounts of timber and clear land for agriculture or mining.
The Kyoto Protocol of 1997, an international agreement aimed at limiting and reducing CO2 emissions, applied only to industrialized countries and countries such as China and India that have exhibited the fastest rate of growth in CO2 emissions. Although some countries have tried to reduce CO2 emissions, the United States initially refused to ratify the agreement and, during the presidential administration of George W. Bush, was slow to try to limit emissions, arguing that industrial production was more important than potential climate change. The delegates to the 2009 United Nations Climate Change Conference, held in Copenhagen, Denmark, attempted to address the issue of regulating CO2 and other emissions further, but little was accomplished. In 2023, the US Department of Energy (DOE) Office of Fossil Energy and Carbon Management announced the availability of $35 million as part of President Biden's Investing in America plan. Part of the funds was to be used to reduce CO2 in the atmosphere.
Bibliography
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"Carbon Dioxide 101." National Energy Technology Laboratory, netl.doe.gov/carbon-management/carbon-storage/faqs/carbon-dioxide-101. Accessed 15 July 2024.
"DOE Announces $35 Million to Accelerate Carbon Dioxide Removal." Office of Fossil Energy and Carbon Management, Department of Energy, September 29, 2023, www.energy.gov/fecm/articles/doe-announces-35-million-accelerate-carbon-dioxide-removal. Accessed 18 July 2023.
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