Climate Change:The Effects of Carbon Dioxide on the Earth’s Atmosphere

Greenhouses Gases in Earth’s Atmosphere

The following gases in the Earth’s atmosphere are known as the greenhouse gases (water vapor, carbon dioxide, methane, nitrous oxide, chlorofluorocarbons or CFCs and ozone). These gases are naturally present in the Earth’s atmosphere. Human activities, such as the burning of fossil fuels (coal, oil and gas) to generate energy have contributed to the rise in the atmospheric CO2 in the last 200 years.

Carbon Dioxide in the Earth’s Atmosphere

The sources of the atmospheric CO2 include volcanic eruptions, combustion and decay of organic matter (dead plants and animals), cellular respiration, burning of fossil fuels, deforestation, and production of cement by humans.

What causes Climate Change?

The Greenhouse Effect is known by scientists to be causing global warming leading to climate change. The greenhouse effect is a process that occurs when greenhouse gases (water vapor, carbon dioxide, methane, nitrous oxide, CFCs) in Earth's atmosphere trap the Sun's heat from escaping into the space. This process makes Earth much warmer than it would be without an atmosphere.

Scientific Evidence of Climate Change

Increase in the atmospheric CO2 leads to global warming of the Earth and causes climate change. The following are the scientific evidence of climate change: Global Temperature Rise, Warming Oceans, Shrinking Ice Sheets, Glacial Retreat, Decreased Snow Cover, Sea Level Rise, Declining Arctic Sea Ice, Extreme Events, and Ocean Acidification.

Global Temperature Rise

The planet's average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere.

Warming Oceans

The oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of more than 0.4 degrees Fahrenheit since 1969.

Shrinking Ice Sheets

The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA's Gravity Recovery and Climate Experiment show Greenland lost an average of 286 billion tons of ice per year between 1993 and 2016, while Antarctica lost about 127 billion tons of ice per year during the same time period. The rate of Antarctica ice mass loss has tripled in the last decade.

Glacial Retreat

Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.

Decreased Snow Cover

Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and that the snow is melting earlier.

Sea Level Rise

Global sea level rose about 8 inches in the last century. The rate in the last two decades, however, is nearly double that of the last century and is accelerating slightly every year.

Declining Arctic Sea Ice

Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades.

Extreme Events

The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950. The U.S. has also witnessed increasing numbers of intense rainfall events, leading to flooding.

Ocean Acidification

Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent. This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans to form carbonic acid. The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year. 

Author:Dr. Sunday Iwalaiye, CPhys, CSciTeach, with contribution from NASA.