Reply #6: the article isn't talking about CO2-destroying machines per se

[treepig]

rather, just strategies to stabilize atmosphere levels at 500 ppm by 2054 (btw, a rather modest goal since that's already almost double historical levels) and then (if i understand correctly) go to net zero emissions by 2125.

Here are the nitty gritty details (sorry the table got all fucked up, but if you're really determined, you can glean some information from this jumble):

Table 1. Potential wedges: Strategies available to reduce the carbon emission rate in 2054 by 1 GtC/year or to reduce carbon emissions from 2004 to 2054 by 25 GtC.

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Option Effort by 2054 for one wedge, relative to 14 GtC/year BAU Comments, issues

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Energy efficiency and conservation

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Economy-wide carbon-intensity reduction (emissions/$GDP) Increase reduction by additional 0.15% per year (e.g., increase U.S. goal of 1.96% reduction per year to 2.11% per year) Can be tuned by carbon policy
1. Efficient vehicles Increase fuel economy for 2 billion cars from 30 to 60 mpg Car size, power
2. Reduced use of vehicles Decrease car travel for 2 billion 30-mpg cars from 10,000 to 5000 miles per year Urban design, mass transit, telecommuting
3. Efficient buildings Cut carbon emissions by one-fourth in buildings and appliances projected for 2054 Weak incentives
4. Efficient baseload coal plants Produce twice today's coal power output at 60% instead of 40% efficiency (compared with 32% today) Advanced high-temperature materials



Fuel shift

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5. Gas baseload power for coal baseload power Replace 1400 GW 50%-efficient coal plants with gas plants (four times the current production of gas-based power) Competing demands for natural gas



CO2 Capture and Storage (CCS)

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6. Capture CO2 at baseload power plant Introduce CCS at 800 GW coal or 1600 GW natural gas (compared with 1060 GW coal in 1999) Technology already in use for H2 production
7. Capture CO2 at H2 plant Introduce CCS at plants producing 250 MtH2/year from coal or 500 MtH2/year from natural gas (compared with 40 MtH2/year today from all sources) H2 safety, infrastructure
8. Capture CO2 at coal-to-synfuels plant Introduce CCS at synfuels plants producing 30 million barrels a day from coal (200 times Sasol), if half of feedstock carbon is available for capture Increased CO2 emissions, if synfuels are produced without CCS
Geological storage Create 3500 Sleipners Durable storage, successful permitting



Nuclear fission

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9. Nuclear power for coal power Add 700 GW (twice the current capacity) Nuclear proliferation, terrorism, waste



Renewable electricity and fuels

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10. Wind power for coal power Add 2 million 1-MW-peak windmills (50 times the current capacity) "occupying" 30 x 106 ha, on land or offshore Multiple uses of land because windmills are widely spaced
11. PV power for coal power Add 2000 GW-peak PV (700 times the current capacity) on 2 x 106 ha PV production cost
12. Wind H2 in fuel-cell car for gasoline in hybrid car Add 4 million 1-MW-peak windmills (100 times the current capacity) H2 safety, infrastructure
13. Biomass fuel for fossil fuel Add 100 times the current Brazil or U.S. ethanol production, with the use of 250 x 106 ha (one-sixth of world cropland) Biodiversity, competing land use



Forests and agricultural soils

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14. Reduced deforestation, plus reforestation, afforestation, and new plantations. Decrease tropical deforestation to zero instead of 0.5 GtC/year, and establish 300 Mha of new tree plantations (twice the current rate) Land demands of agriculture, benefits to biodiversity from reduced deforestation
15. Conservation tillage

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Apply to all cropland (10 times the current usage)

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Reversibility, verification