CO2

Carbon dioxide (CO2) is a greenhouse gas that is emitted when fossil fuels, such as oil, coal, and natural gas, are burned. The burning of fossil fuels is the main source of human-caused CO2 emissions, which contribute significantly to climate change. The concentration of CO2 in the Earth's atmosphere has been steadily increasing since the Industrial Revolution, due to the burning of fossil fuels and other human activities. This increase in CO2 has led to a warming of the Earth's surface and a change in the Earth's climate. The climate emergency we are currently facing is largely due to the excess of CO2 and other greenhouse gases in the atmosphere, which trap heat and cause the Earth's temperature to rise. Reducing CO2 emissions is critical in order to mitigate the negative impacts of climate change and protect the planet for future generations. This can be achieved through a variety of measures, including transitioning to clean, renewable energy sources, improving energy efficiency, and implementing policies and regulations to reduce CO2 emissions.

Over the past 800,000 years, atmospheric CO2 levels have fluctuated between approximately 180 ppm and 280 ppm, with an average of around 260 ppm. These fluctuations have been driven by natural processes such as volcanic eruptions and changes in the Earth's orbit.

However, it is important to note that atmospheric CO2 levels have been steadily increasing over the past few centuries due to human activities such as burning fossil fuels and deforestation. The concentration of CO2 in the atmosphere is currently around 415 ppm, which is significantly higher than the natural range that has occurred over the past 800,000 years. This rapid increase in CO2 levels is a major contributor to climate change, which is having a range of impacts on the planet and its ecosystems.

The Keeling Curve 

A daily record of global atmospheric carbon dioxide concentration
maintained by Scripps Institution of Oceanography at UC San Diego