Atmospheres and Clouds
Compare current CO2 levels to the concentrations from the past 450,000 years. Based on these websites and the textbook, answer the following questions:
Explain how the carbon cycle works.
What is the current CO2 concentration in parts per million (ppm)?
How does this compare to the highs or lows over the past 450,000 years?
What are the three most abundant sources from which humans add CO2 to the atmosphere?
Explain the two main natural carbon sinks that remove CO2 from the atmosphere.
Explain in detail two ways deforestation contributes to the increase in CO2 levels.
What are some other greenhouse gases, and how do their concentrations compare to the past 450,000 years?
Based on the data, are humans contributing to climate change, or is it strictly a natural part of the cycle? Defend your answer. You must weigh all of the data, and use them to formulate your conclusion.
Sample Solution
Atmosphere and Clouds
All of the atoms that are building blocks of living things are a part of biogeochemical cycles. The most common of these are the carbon and nitrogen cycles. Carbon moves from the atmosphere to plants. In the atmosphere, carbon is attached to oxygen in a gas called carbon dioxide. Through the process of photosynthesis, carbon dioxide is pulled from the air to produce food made from carbon for plant growth. Carbon moves from plants to animals. Through food chains, the carbon that is in plants moves to the animals that eat them. Animals that eat other animals get the carbon from their food too. Carbon dioxide in the atmosphere is now reaching levels 50% higher than when humanity began large-scale burning of fossil fuels during the industrial revolution. Recent measurements from the Mauna Loa Observatory in Hawaii show that for several days in February and March 2021, atmospheric carbon dioxide levels exceeded 417 parts per million (ppm).
