It is relatively easy to calculate the amount of carbon released worldwide due to fossil-fuel burning. All countries track how much coal, oil, and natural gas they use as a way of measuring the health of their economies. Plus, many countries have some sort of environmental protection agency which tracks emissions. So how many tons of CO₂ are released to the atmosphere from fossil-fuel burning is fairly accurately known.

1. Download the Excel spreadsheet file indusco2.xls (You will need Excel 5.0 or higher.) or the text version if your spreadsheet program cannot read Excel 5.0 files. This file contains the total emissions from fossil-fuel burning in million metric tons of carbon for each year since 1959.

Aside: The fourth column lists tons of carbon per capita. Notice that every human on average causes the emission of 1.1 tons of carbon each year. If you live in the U.S., this value is probably two to three times as great. Also notice how the per capita value increases until the mid-70s, when the energy crisis occurred and conservation became a household word.

2. Using the data in the total column, calculate how much CO₂ in parts per million was released to the atmosphere each year.

3. Compare your calculated increase in CO₂ to the actual increase in CO₂ levels per year as measured at Mauna Loa, Hawaii. Perhaps you should graph the two sets of values to aid in analyzing the results.

4. Another way to look at the data is to compare the total amount of CO₂ in parts per million released from fossil fuels with the yearly average concentration at Mauna Loa, Hawaii. To do this, add up all the yearly increases up to and including the year of interest for the fossil-fuel data. In December 1958, the atmospheric concentration of CO₂ was 314.50 ppm. To get 1959's value, add 314.50 to the increase for 1959. This value should be very close to the yearly average value from the Mauna Loa data set (You will need Excel 5.0 or higher.) or the text version.

5. If the calculated and actual increases are not equal to each other, list possible explanations which could account for the discrepancies. Hint: think in terms of the Carbon cycle.

[ Yellowstone Biomass Burning ] [ Seasonal Vegetation Changes ]
[ Fossil Fuel Burning ] [ Fit CO₂ Curve ]
[ Balancing the Carbon Cycle ] [ Uncertainty in CO₂ Data ]
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