CO2 emissions are the release of carbon dioxide into the atmosphere. There are both natural and human sources of carbon dioxide emissions. Natural sources come from organisms respiring (breathe) or decomposing (decay), forest fires, volcanic eruptions and ocean release. Human sources come from activities such as deforestation, cement production, and the burning of fossil fuels like coal, oil and natural gas (source).
CO2 is the most abundant greenhouse gas in the atmosphere: along with methane and other pollutants, it builds up in the atmosphere and causes the greenhouse effect, a process whereby gases accumulate and trap the heat from solar radiation and cause the planet’s global surface temperature to rise (source).
Life on Earth has always released a certain level of carbon dioxide – in fact, it’s essential – since the natural greenhouse effect keeps Earth’s average surface temperature above freezing. The carbon cycle is nature’s way of maintaining a stable climate on Earth: when carbon dioxide is naturally released by animal decomposition or volcanic eruptions, it is eventually captured by plants, dissolved into oceans or sequestered by trees. This balance of carbon levels allows the planet to remain hospitable for life (source).
Many climate change deniers will say that global temperatures have been high in the past, and that the temperature increase we’re seeing now is nothing new and is just natural variation. However, the levels at which we are releasing CO2 into the atmosphere today are far beyond natural. Levels of atmospheric CO2 had been stable for about 20 million years until humans began burning fossil fuels during the Industrial Revolution of the late 18th century (source).
There are two ways to limit CO2 levels: reducing emissions and removing carbon dioxide from the atmosphere. The single most important way to reduce human-induced emissions is to transition from fossil fuels to renewable energy. To remove carbon dioxide from the atmosphere, we need widespread reforestation, regenerative agriculture, and advanced carbon capture technology (source).
