Please contemplate this figure for a few moments:
1. The area labeled “mitigated GHG emissions” would include CO2 capture from point sources like fossil fuel power plants, and storage of that CO2, if renewable and nuclear power generation do not completely replace them.
(a) True (b) False
2. The area labeled “mitigated GHG emissions” would include CO2 capture from cement plants and iron & steel foundries, and storage of that CO2, if these continue to calcine limestone (mostly calcite, CaCO3) to produce lime (CaO)
(a) True (b) False
3. CO2e refers to CO2 plus equivalent amounts of other greenhouse gases, based on their “Global Warming Potential” (GWP) divided by the GWP for CO2.
(a) True (b) False
4. Assuming that the authors have correctly accounted for uncertainties in the relationship between emissions, atmospheric CO2, and greenhouse warming, according to this diagram, the amount of negative emissions required to maintain global average atmospheric near-surface temperatures less than 2°C higher than those at some “pre industrial” baseline time
(a) is about 10 Gt CO2e/year by 2055 (b) is about 20 Gt CO2e/year by 2100
(c) includes annual increases in soil carbon, ocean carbon, biological carbon, … as well as “conventional” CO2 storage in subsurface pore space
(d) all of the above
5. Compared to the number of tons of oil produced globally in 2020, according to the latest BP Statistical Review of World Energy, the mass of 10 billion tons of CO2 per year is
(a) about 10% (b) about half (c) about 2.5 x larger (d) about 10 x larger
6. Still referring to the diagram on the previous page, if the area labeled “mitigated GHG emissions” is smaller, for example in 2055, with correspondingly larger brown areas labeled “other GHG” and “CO2”, assuming that the authors of the figure have correctly related emissions to atmospheric GHG concentrations and to warming, in order to prevent global warming of more than 2° relative to a pre-industrial baseline, the blue area of negative emissions would have to be
(a) smaller than 10 Gt CO2e per year in 2055 (b) larger than 10 Gt CO2e per year in 2055
7. If, in 2055, average costs for combined CO2e capture – from smokestacks, from air, … – plus transportation plus storage are $50/ton CO2e (2020 dollars), assuming no real growth in the economy (2020 global GDP according to the World Bank), what percentage of global GDP would be required to capture, transport and store 10 Gt CO2e per year?
8. As in (7) but assuming 3% annual growth in global GDP starting from 2020, but no growth in real costs for capture,transport and storage of CO2e, what proportion of 2055 global GDP would be required to capture, transport and store 10 Gt CO2e per year?
9. Give the percentages of 2020 GDP allocated to
(a) wastewater treatment, with your source of information on the cost of treatment, and separately
(b) to solid waste disposal, with your source of information on disposal.
(c) How do the percentages in (7) and (8) compare to the proportion of 2020 GDP (World Bank) arising from (a) the global wastewater treatment market and (b) the global municipal solid waste disposal market in 2020?
