Phase IV: Regional Scale Removal
The atmosphere spans borders, and so should our efforts to remove carbon from it
Regions can benefit by working together to take advantage of the varying distributions of resources, labor, and geography. By working together they can also reach a scale that dramatically pushes down the price per ton of CO2 removed from the atmosphere. CO2 put out by one country, affects the atmosphere of all countries, so it makes sense to work together toward a common goal and to hold each other accountable for our emissions.
In the case of Western Europe, there is an opportunity for countries to team up to offset a greater amount of CO2 than their output. There is an area of the ocean just off the coast of the UK, France, Belgium, and the Netherlands, known as the Southern Bight of the North Sea. This area has extremely strong underwater currents (known as bed shear stress forces) that are capable of sediment transport that could essentially tumble olivine underwater without the need for beaches.
Let’s look at the hard numbers on this project and the real logistics of loading, unloading, and transporting the olivine on a scale that would remove an equivalent of 1.5 gigatons of CO2, about 5% of the worlds yearly CO2 emissions, by weathering 1.2 gigatons of olivine. The plan involves transporting olivine by boat and utilizing an area of 35,000 km^2 out of an adequate area totaling of 250,000 km^2 that has underwater forces capable of transporting and accelerating the weathering of olivine.
- 1.2 gigatons (gt) of olivine is 3000 megacarrier loads of 400,000 metric tons of olivine.
- Based on a model for a 5,000 tonnes per day mine in the USA, the cost of mining and crushing volcanic rock is $7.32 / metric ton.
- For transport, we would use self-unloading megacarriers that can each hold 200,000 tons of olivine.
- Loading and unloading of mega carrier takes (4-5 days)*2 = 10 days
- Speed 15.4 knots (28.5 km/h; 17.7 mph) = 650 km/day
- Travel Outbound/Inbound (~ 2000 km)*2 = 4000 km = 6 days
- Cost of 200,000 ton megacarrier daily operations = ~$40,000/day
- Loading, travel to location, unloading, and travel back = 16 days (although can be less with partial unloading while traveling)
- 16 days x $40,000 = $640,000
- $640,000 operational cost of loading+dumping+travel/200,000 tons per boat = $3.20 cost to distribute each ton
- $3.20 (distribution cost) + $7.32 mining cost = $10.62 / ton of olivine to reach weathering destination in ocean
- $10.62/1.25 (1.25 tons of CO2 removed for each 1 ton of olivine weathered)
=~$8.50 per ton of CO2 removed from atmopshere and ocean