A Natural Cycle - How Do We Know

The video explains how CO2 emissions from burning fossil fuels differ from natural sources. It highlights the role of bookkeeping in tracking fossil fuel usage and compares emissions from volcanoes and fossil fuels. The video also discusses the relationship between oxygen levels and CO2 emissions, showing that oxygen decreases as CO2 from fossil fuels increases. Finally, it identifies tracers that confirm the burning of fossil fuels, which were once living organisms.

How do we track the amount of CO2 produced from burning fossil fuels?

• By counting the number of cars on the road

• Through satellite imagery of industrial areas

• Through bookkeeping of coal and oil usage

• By measuring the number of trees cut down

What percentage of CO2 emissions do volcanoes contribute compared to fossil fuels?

• 25%

• 50%

• 10%

• 1-2%

What is a key difference between CO2 emissions from volcanoes and fossil fuels?

• Fossil fuel CO2 emissions decrease oxygen levels

• Volcanic CO2 emissions do not use oxygen

• Fossil fuel CO2 emissions do not affect oxygen levels

• Volcanic CO2 emissions increase oxygen levels

What happens to oxygen levels as CO2 levels rise from burning fossil fuels?

• Oxygen levels decrease

• Oxygen levels remain constant

• Oxygen levels fluctuate randomly

• Oxygen levels increase

What do tracers indicate about the source of CO2 emissions?

• They come from recent plant growth

• They are primarily from volcanic activity

• They originate from long-dead organic material

• They are from current oceanic processes