UNDERSTANDING GLOBAL CHANGE Discover why the climate and environment changes, your place in the Earth system, and paths to a resilient future
The burning of fossil fuels refers to the burning of oil, natural gas, and coal to generate energy. We use this energy to generate electricity, and to power transportation (for example, cars and planes) and industrial processes. Ever since the invention of the first coal-fired steam engines of the 1700s, our burning of fossil fuels has steadily increased. Across the globe each year we now burn over 4,000 times the amount of fossil fuels burnt during 1776. The effects of the burning of fossil fuels, especially carbon dioxide, are having far-reaching effects on our climate and ecosystems.
The burning of fossil fuels is the primary cause of current climate change, altering the Earth’s ecosystems and causing human and environmental health problems.
Fossil fuels form over millions of years from the burial of photosynthetic organisms, including plants on land (which primarily form coal) and plankton in the oceans (which primarily form oil and natural gas). To grow these organisms removed carbon dioxide from the atmosphere and the ocean, and their burial inhibited the movement of that carbon through the carbon cycle. The burning of this fossil material returns this carbon back into atmosphere as carbon dioxide, at a rate that is hundreds to thousands of times faster than it took to bury, and much faster than can be removed by the carbon cycle. Thus, the carbon dioxide released from the burning of fossil fuels accumulates in the atmosphere, some of which then dissolves in the ocean causing ocean acidification.
The burning of fossil fuels affects the Earth system in a variety of ways. Some of these ways include:
Releasing the greenhouse gases carbon dioxide (CO2) and nitrous oxide (N2O) into the atmosphere, which intensifies the greenhouse effect (the re-radiation of heat in the atmosphere), increasing the Earth’s average air temperatures. These greenhouse gases can remain in the atmosphere for decades to hundreds of years.
Emitting an array of pollutants that reduce air quality and harm life, especially sulfur dioxide, nitrogen oxides, and airborne particles such as soot. Poor air quality can cause respiratory disease.
The airborne particles also increase the reflectivity of the atmosphere, which has a slight cooling effect. The reason is that the airborne particles, such as soot and sulfate aerosols (from sulfur dioxide), reflect some sunlight back into space, increase cloud formation, and make clouds more reflective. The net effect of burning fossil fuels is warming because the cooling is small compared with the heating caused by the greenhouse effect, in part because airborne particles only stay suspended in the atmosphere for a few days to months, while greenhouse gases that cause warming remain in the atmosphere for many decades to hundreds of years.
Changing patterns of snow and ice melt. Airborne particles (especially soot) that settle on snow increase the absorption of sunlight due to their dark color, heating the surface of the snow causing melting. In certain parts of the world, the presence of soot (in addition to global warming) has caused winter ice and snow melts earlier and faster today than in previous decades, which also changes local patterns of freshwater availability.
Increasing the acidity of precipitation. Sulfur dioxide (SO2), nitrogen oxides (NOx), and carbon dioxide (CO2) react with water vapor, oxygen, and other chemicals to form acid rain. Acid rain can contaminate freshwater sources, resulting in harmful algal blooms that reduce water oxygen levels and harm fish populations and other wildlife. Additionally, acid rain increases chemical weathering of rocks, including man made structures.
Using large amounts of freshwater. Power plants that burn fossil fuels cool their systems by removing freshwater from local rivers and lakes. The warm water returned to nearby ecosystems can cause stress for local species.
Can you think of additional cause and effect relationships between the burning of fossil fuels and other parts of the Earth system?
Visit the greenhouse effect, greenhouse gases, and temperature pages to learn more about how burning fossil fuels affects global climate and ecosystems.
Investigate
Learn more in these real-world examples, and challenge yourself to construct a model that explains the Earth system relationships.
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