With a voice like Sean Connery, Professor Emeritus. Dr. Calvin of the UW School of Medicine (new book at http:\/\/williamcalvin.org )\u00c2\u00a0 talked about his ideas for how to mitigate rising CO2 levels.\u00c2\u00a0 His concerns arise in part from the 2-3x increase in the global drought index during the 20th century (Das et al., 2004; updated 2006).\u00c2\u00a0 He also noticed that around 1976 El Nino conditions began to predominate, though La Nina conditions were dominant beforehand.<\/p>\n
In addition to more prevalent abrupt climate shifts, there were some near misses (like heart attacks?) since 1976:<\/p>\n
We need to sequester about 600 Gt of carbon over next 20 years to get back to pre-industrial levels.\u00c2\u00a0 Freeman Dyson’s favorite fix is doubling global forests, but climate conditions are getting worse for trees generally.\u00c2\u00a0 Photosynthesis already removes 210 GtC\/yr, though it is mostly returned through respiration and decomposition.\u00c2\u00a0 This means we need new production that is sequestered for long time periods (probably best done in the voluminous oceans).<\/p>\n
Much of the anthropogenic CO2 that has already been sunk is in the N Atlantic.\u00c2\u00a0 Major inputs are 2GtC\/yr from deforestation and 8 from fossil fuels and cement.\u00c2\u00a0 92 are absorbed into ocean, and 90 are released.\u00c2\u00a0 In ocean 48 are photosynthesized, 37 are respired, and 11 settle through thermocline, and 0.01 are deposited on bottom.\u00c2\u00a0 So the big reservoir is dissolved organic carbon; it is 100x larger than the living biomass.<\/p>\n
In the cold depths, about 1\/2 of new DOC from upper ocean is soon converted into total CO2.\u00c2\u00a0 The rest has a 6kyr residence time (maybe because of multiple passes through surface system before removal).<\/p>\n
Intervention A:\u00c2\u00a0 4x the settling rate (11 -> 44), but that would require a 4x increase in global productivity.<\/p>\n
Intervention B: Pump down 30GtC\/yr (600Gt over 20 years) maybe by fertilizing near downwelling zones (Greenland Sea whirl pools?) OR by mechanical pumping with wind or wave power.<\/p>\n
Algaculture has advantage of controlling respiration.\u00c2\u00a0 Assume 50g of algae\/m2\/d about half of which is carbon.\u00c2\u00a0 Thus it takes 10-4 m2 (fingernail) to grow 1 gC\/yr.\u00c2\u00a0 To sink 30Gt, you’d need 3×10^9 m2 or 3000 km2.<\/p>\n
Field trials?\u00c2\u00a0 3,900 oil and gas platforms are in operation off coasts of Louisiana and Texas.\u00c2\u00a0 The north Sea presents a similar opportunity.<\/p>\n","protected":false},"excerpt":{"rendered":"
With a voice like Sean Connery, Professor Emeritus. Dr. Calvin of the UW School of Medicine (new book at http:\/\/williamcalvin.org )\u00c2\u00a0 talked about his ideas for how to mitigate rising CO2 levels.\u00c2\u00a0 His concerns arise in part from the 2-3x … Continue reading