>If we can incentivize people to make useful products out of all that CO2 just floating in the atmosphere, then maybe, just _maybe_, we can start fixing the mess we made.
I'm sure most people are picturing factories here, but using low/appropriate tech as well is essential. Building soil and woody biomass can absorb enormous amounts of carbon.
The question essentially becomes, how much biomass per hectare are we talking about? Absorbing the 350 teratonnes of human emitted carbon [1] over the 11.7 billion hectares of Earth's non-tundra land surface [2] works out to 30 tonnes of carbon per hectare. If you exclude deserts it's 42 tonnes per hectare, but the technology already exists to successfully "green" deserts.
That's 30 trees per hectare, at 1 tonne per tree.[3] Or 3 kg per square meter of soil carbon, the equivalent of 25 cm of topsoil Soil carbon is stored up to 40 meters down by deep rooted plants, so in practice this isn't a problem. [4]
Most of our land management is via agricultural, so agricultural reform is the only lever long enough to make a dent. Practically this means switching from soil destroying tillage to soil building cover crops, long-distance imported fertilizer to in-situ fertility produced by soil organisms[5], and ecologically unstable monocultures to resiliant polyculture and agroforestry systems.
If you run the numbers trying to use factories alone the cost is astronomical. It's larger* than the world's global energy infrastructure, because thermodynamics is working against you.
An overhaul of agriculture using modern environmental biology is the only thing with a lever long enough to make the numbers close. Plus it simultaneously solves the existential risks posed by our laughably unsustainable food production system and the collapse of ecosystem services by habitat destruction.[6]
> Absorbing the 350 teratonnes of human emitted carbon ...
And that was the first time I ever saw anyone throwing a number for how many tonnes we are really talking about in any debate I have seen either here or on AT.
Congrats! More numbers, less politics!
(Not saying it is correct, I haven't verified, -but unlike "celebrity X says we should do something now" this is something that can be measured and discussed rationally.)
I'm sure most people are picturing factories here, but using low/appropriate tech as well is essential. Building soil and woody biomass can absorb enormous amounts of carbon.
The question essentially becomes, how much biomass per hectare are we talking about? Absorbing the 350 teratonnes of human emitted carbon [1] over the 11.7 billion hectares of Earth's non-tundra land surface [2] works out to 30 tonnes of carbon per hectare. If you exclude deserts it's 42 tonnes per hectare, but the technology already exists to successfully "green" deserts.
That's 30 trees per hectare, at 1 tonne per tree.[3] Or 3 kg per square meter of soil carbon, the equivalent of 25 cm of topsoil Soil carbon is stored up to 40 meters down by deep rooted plants, so in practice this isn't a problem. [4]
Most of our land management is via agricultural, so agricultural reform is the only lever long enough to make a dent. Practically this means switching from soil destroying tillage to soil building cover crops, long-distance imported fertilizer to in-situ fertility produced by soil organisms[5], and ecologically unstable monocultures to resiliant polyculture and agroforestry systems.
If you run the numbers trying to use factories alone the cost is astronomical. It's larger* than the world's global energy infrastructure, because thermodynamics is working against you.
An overhaul of agriculture using modern environmental biology is the only thing with a lever long enough to make the numbers close. Plus it simultaneously solves the existential risks posed by our laughably unsustainable food production system and the collapse of ecosystem services by habitat destruction.[6]
[1] http://petrolog.typepad.com/climate_change/2010/01/cumulativ...
[2] http://cnx.org/contents/TWFXbERo@1/The-main-biomes
[3] http://cabiblog.typepad.com/hand_picked/2011/06/ever-wondere...
[4] http://www.soilquality.org.au/factsheets/organic-carbon
[5] https://www.youtube.com/watch?v=x2H60ritjag
[6] http://unctad.org/en/PublicationsLibrary/ditcted2012d3_en.pd... [PDF, 5.2MB]