Carbon Dioxide (CO2): Carbon dioxide enters the atmosphere through burning fossil fuels, solid waste, trees, volcanos, and also as a result of certain chemical reactions (e.g., cement production). Carbon dioxide is removed from the atmosphere when it is absorbed by plants as part of the biological carbon cycle. Nearly 80% of all greenhouse gas emissions in the US is from carbon dioxide.
Methane (CH4): Methane is emitted during the production and transport of coal, natural gas, and oil. Methane emissions also result from livestock and other agricultural practices, land use, and by the decay of organic waste in municipal solid waste landfills. While methane emissions only account for about 11% of GHG emissions in the US, methane is more efficient at trapping radiation than carbon dioxide. Methane’s global warming potential is 28 times greater than carbon dioxide.
Nitrous Oxide (N2O): Nitrous oxide is emitted during agricultural, land use, and industrial activities; combustion of fossil fuels and solid waste; as well as during treatment of wastewater. Nitrous oxide oxide accounts for only 6% of GHG emissions in the US, but has a large impact because its global warming potential is 265 times that of carbon dioxide.
Water (H2O): Water is a naturally occurring greenhouse gas and most abundant. Water vapor amplifies global warming cause by other greenhouse gases. Water vapor has a very short lifespan in the atmosphere due to precipitation.
Fluorinated gases: Hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride are synthetic, powerful greenhouse gases that are emitted from a variety of household, commercial, and industrial applications and processes. Fluorinated gases do have a natural cause, unlike the previous GHG discussed above. They are produced entirely from human related manufacturing and industrial processes.
The greenhouse effect is a natural process essential to life on Earth, maintaining a stable and hospitable climate for millions of years. However, human activities have significantly increased atmospheric greenhouse gas concentrations, disrupting this long-standing balance and driving a rapid rise in global temperatures. In the next page, we’ll explore how this warming translates into climate change—examining its real-world impacts, the science behind future projections, and the energy solutions that can help stabilize our planet’s climate.
Text description of the Greenhouse Effect image.
The image illustrates the greenhouse effect, divided into two sections: "Natural" and "Human-Enhanced." On the left, under "Natural," the atmosphere is shown as a curved line with "Greenhouse Gases" labeled. A large sun in the upper left corner emits an arrow labeled "Sun Energy" pointing towards Earth. Some of this energy is reflected as "Heat" back into space. The landscape includes small, subtle green shapes resembling hills and grass. The gases CH₄ and CO₂ are labeled above the line. On the right side, under "Human-Enhanced," the same concept is depicted, but with a denser layer of gases, labeled "More Greenhouse Gases." Additional visuals include industrial icons like factories. The arrows indicating heat reflection are more prominent, suggesting increased heat retention. The background is a gradient of blue, with text boxes providing explanations under each heading.