Question

This graph shows how the amount of carbon dioxide (CO2) in the atmosphere has increased with time. Where is this CO2 coming from? Discuss the primary source of the CO2 and some of the activities that release the CO2 into the atmosphere.

(2 points)
grader 6

Answer 1

The primary source of the rising atmospheric CO2 is human activity — mainly the burning of fossil fuels (coal, oil, natural gas) that releases carbon stored underground. Major activities that emit CO2 include:
- Electricity and heat generation from coal and natural gas
- Transportation (cars, trucks, ships, airplanes burning petroleum)
- Industry and manufacturing (steel, chemicals, etc.)
- Deforestation and land‑use change (cutting/burning forests that otherwise store carbon)
- Cement production (calcination of limestone releases CO2)

Natural sources (respiration, decomposition, volcanoes) exist but were roughly balanced by sinks before the industrial era; the recent long-term increase is driven by these human emissions.