Greenhouse gases (GHGs) are atmospheric gases that absorb and emit radiation within the thermal infrared range, leading to the greenhouse effect. This phenomenon is fundamental to life as we know it, helping to maintain the Earth's surface temperature and making it conducive for human habitation, agriculture, and biodiversity. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone. Human activities, particularly since the Industrial Revolution, have significantly increased the concentrations of CO2, methane, and nitrous_oxide, enhancing the natural greenhouse effect, which in turn contributes to global warming and climate change.
The largest source of anthropogenic greenhouse gas emissions is the burning of fossil fuels for electricity, heat, and transportation. CO2 is the most prevalent greenhouse gas emitted by human activities, particularly through the combustion of oil, coal, and natural gas. Methane, another significant greenhouse gas, is about 25 times more potent than CO2 in terms of trapping heat in the atmosphere over a 100-year period. It is released during the production and transport of coal, oil, and natural gas. Furthermore, methane emissions come from livestock and other agricultural practices and by the decay of organic waste in municipal solid waste landfills.
The impact of greenhouse gases on the Earth's temperature is measured in terms of their global warming potential (GWP). GWP is a relative measure designed to quantify the amount of heat a greenhouse gas traps in the atmosphere up to a specific time horizon, compared to the same amount of CO2. For instance, over a 20-year period, the GWP of methane is approximately 84 times that of CO2. This means that methane, while less abundant than CO2, is significantly more effective at warming the Earth on a per molecule basis over this time frame, making it a crucial target for climate change mitigation strategies.
International efforts to address the accumulation of greenhouse gases in the atmosphere include treaties and agreements like the Kyoto Protocol and the Paris Agreement. These agreements aim to cap and reduce GHG emissions through various commitments by countries around the world. Innovations in renewable energy, energy efficiency improvements, and increased forestation are among the strategies being employed to decrease the concentration of GHGs. The role of individuals and corporations in reducing their carbon footprint is also increasingly emphasized, promoting a shift towards a more sustainable and low-carbon future. Through collaborative global action and the adoption of green_technology, there is hope for stabilizing and eventually reducing global GHG concentrations.