The current concentration of carbon dioxide in the atmosphere is far higher than the natural range over the last 650,000 years, and is increasing rapidly for several reasons. Some of the main factors that have contributed to this increase include:
- Burning of fossil fuels: The most significant source of carbon dioxide emissions is the burning of fossil fuels, such as coal, oil, and natural gas. These fuels are rich in carbon, and when they are burned, they release large amounts of carbon dioxide into the atmosphere. Over the past century, the global demand for energy has increased dramatically, leading to a corresponding increase in the burning of fossil fuels and the release of carbon dioxide into the atmosphere.
- Deforestation: Trees and other vegetation absorb carbon dioxide from the atmosphere as part of the process of photosynthesis. When trees are cut down and burned, or otherwise removed from the landscape, this carbon is released back into the atmosphere. Deforestation is therefore a major source of carbon dioxide emissions, and can contribute to the increasing concentration of carbon dioxide in the atmosphere.
Overall, the current high levels of carbon dioxide in the atmosphere are the result of human activities, such as the burning of fossil fuels and deforestation, which have released large amounts of carbon dioxide into the atmosphere. These activities have led to a rapid increase in the concentration of carbon dioxide in the atmosphere, far beyond the natural range of concentrations over the last 650,000 years.