Answer Happy

The U.S. produces about 4.2 metric tons (4,200 kg) of carbon perperson per year. The purpose of this problem is to confirm thisnumber and to estimate the temperature change associated with theglobal carbon footprint. A. Calculate the carbon emissions perperson per year in the U.S. Use the energy and carbon intensitydata in Table 1. The U.S. consumed about 103 EJ of energy in 2021(down a bit because of the pandemic). The U.S. population is about332 million. Compare your answer to the expected value of about4,200 kg C per person per year. (As an aside, 4,200 kg C per personper year is about 15,520 kg CO2 per person per year.) Table 1: U.S.Energy Data Contribution to U.S. Energy (%) Carbon Intensity (gC/MJ) Petroleum 36% 19.7 Coal 11% 24.2 Natural gas 32% 13.8 Nuclearand renewables 20% 0 (approx.) M = mega = 106 , G = giga = 109 , T= tera = 1012, P = peta = 1015, and E = exa = 1018; 1 metric ton =1,000 kg Source: US Energy Information Administration(www.eia.gov/energyexplained/us-energy-facts) B. The global averagecarbon footprint is about 1,220 kg of carbon per person per yearfor 7.8 billion people (2020 data). Translate this value into anannual increase in the CO2 concentration in the atmosphere in ppm.Assume 40% of the emitted carbon remains in the atmosphere. C.There is a growing consensus that a 1.5oC temperature increase overthe preindustrial temperature would result in permanent changes tothe environment. The temperature now is about 1oC above thepreindustrial temperature. How long can we continue to producecarbon dioxide at the rate you calculated in Part B before theglobal temperature increases 0.5 more degree Celsius? Assume theCO2 concentration now is 420 ppm.