Energy and the environment explained Greenhouse gases and the climate

Greenhouse gas emissions and atmospheric concentrations have increased over the past 150 years

Emissions of several important greenhouse gases that result from human activity have increased substantially since large-scale industrialization began in the mid-1800s. Most of these human-caused (anthropogenic) greenhouse gas emissions were carbon dioxide (CO₂) from burning fossil fuels.

Concentrations of CO₂ in the atmosphere are naturally regulated by many processes that are part of the global carbon cycle. The flux, or movement, of carbon between the atmosphere and the earth's land and oceans is dominated by natural processes such as plant photosynthesis. Although these natural processes can absorb some of the anthropogenic CO₂ emissions produced each year, starting in about 1950, CO₂ emissions began exceeding the capacity of these processes to absorb carbon.

This imbalance between greenhouse gas emissions and the ability for natural processes to absorb those emissions has resulted in a continued increase in atmospheric concentrations of greenhouse gases. Concentrations of CO₂ in the atmosphere in 2022 were about 1.5 times greater than the concentrations in 1850.

Greenhouse gases warm the planet

Scientists know with virtual certainty that high levels of greenhouse gasses in the atmosphere tend to warm the planet. In computer-based models, rising concentrations of greenhouse gases result in a rising average surface temperature of the earth over time. Rising temperatures may produce changes in precipitation patterns, storm severity, and sea level. Collectively, this phenomena is commonly referred to as climate change.

The Intergovernmental Panel on Climate Change (IPCC) suggests that the earth's climate warmed by an estimated 0.92 degrees Centigrade (1.66 degrees Fahrenheit) between 1880 and 2012 ¹ and that human activity is likely an important driving factor. The IPCC's Sixth Assessment Report (Chapter 3: Human Influence on the Climate System) states, "It is unequivocal that human influence has warmed the atmosphere, ocean and land since pre-industrial times."

The report further states, "The likely range of human-induced warming in global-mean surface air temperature in 2010–2019 relative to 1850–1900 is 0.8°C–1.3°C." The IPCC concluded that the increasing concentration of the major greenhouse gases (carbon dioxide, methane, and nitrous oxide) “are unprecedented over at least the last 800,000 years.” The IPCC ties this rise directly to human activity.

Last updated: June 18, 2024.