Toward climate geoengineering?
Andrew Glikson [0]
Earth and paleo-climate scientist
Australian National University
With global atmospheric CO2 levels rising at about 2 ppm/year toward 388 ppm [1], or near-440 ppm CO2-e (including methane effects), John Holdren [2], in his first interview since being appointed as Obama’s new science adviser, revealed in an interview with AP (8 April, 09) “global warming is so dire, the Obama administration is discussing radical technologies to cool Earth’s air” which “as an experimental measure would only be used as a last resort … It's got to be looked at … We don't have the luxury of taking any approach off the table … One such extreme option includes shooting pollution particles into the upper atmosphere to reflect the sun's rays.”
Holdren compared the way humanity is facing dangerous climate change to passengers in a car with bad brakes heading toward a cliff in a fog, saying, “The sensible passengers will certainly say: ‘Let's put on the brakes, even if we don't know it will save us [3]. It may be too late. We don't know exactly where the cliff is. . . . Let's get on with it’.”.
Holdren is not alone in considering geoengineering [4]. The National Academy of Science is also looking at the subject in its new multidiscipline climate challenges program. The American Meteorological Society is preparing a statement on geoengineering, stating “it is prudent to consider geoengineering's potential, to understand its limits and to avoid rash deployment.” The British parliament has also discussed the idea..
Climate geoengineering ideas fall into at least four principal categories:
(1) Increased reflectivity (albedo) of the atmosphere [5], injecting sulphur dioxide (suggested by Paul Crutzen, the Nobel Prize winner atmospheric chemist), or alumina particles, or even installing reflectors in space [6]. The effects of sulphur injections would simulate volcanic events, such as of Pinatubo (1991) or Tambora [7] (1816), which resulted in cooling of the Earth’s surface [8] by about 0.5 degrees. (;).
(2) Increased sequestration of CO2 in the oceans [9], enhancing algal blooms and phytoplankton photosynthesis through fertilization with iron filings [10], or constructing vertical pipe systems designed to enhance oceanic circulation and CO2 intake [11] from the atmosphere.
(3) Biochar burial and soil enrichment. Combustion of plant waste under low oxygen conditions and burial as charcoal [12], removing carbon from atmospheric circulation and enhancing plant growth and photosynthesis, as well as soil enrichment [13]. A major controversy erupted with objections to biochar by George Monbiot [14], involving James Lovelock and James Hansen
(4) Chemical sequestration involving combination of CO2 with sodium hydroxide (NaOH) installed in pipe systems (“sodium trees” [15]), followed by separation and burial of CO2, costed at about $US300 a ton [16]. A back of an envelope calculation suggests the reduction of atmospheric CO2 by 50 ppm would cost about $
Increasingly a “technological fix” may look attractive to Obama and possibly the EU (and Rudd?), in view of at least three major obstacles to CPRS and ETS schemes:
First, due to the cumulative nature of atmospheric CO2, neither 5/15% nor 25/40% emission reduction by 2020 relative to 2000 would be able to prevent runaway climate change. This is because CO2 levels, now at 387 ppm and rising by 2 ppm/year, will exceed 400 ppm by 2020, well into the high danger zone [18]. Assuming CO2 emissions are reduced by even 40% relative to 2000, it would keep rising by a minimum of 1.2 ppm/year reaching levels near or above 450 ppm by 2050, and this is without even accounting for the effects of methane, likely reduced CO2 intake by the oceans and increase in positive feedbacks from the biosphere. At 450 ppm, with lag effects, polar ice sheets undergo advanced melting [19], with consequent major sea level rise [20],
It is not clear how many of the submissions [21]made to the Australian Senate Inquiry into the CPRS take account of this factor.
Second, it is a good question whether even such feeble CPRS attempts would not be squashed by the all powerful fossil fuel lobby, currently supporting a massive well-funded disinformation campaign [22], including claims [23] that the Earth is “cooling” [24], accusing scientists and environmentalists of “environmental thuggery” [25], and including threats such as by Republican congress woman Michelle Bachmann [26](“I want people in Minnesota armed and dangerous on this issue of the energy tax because we need to fight back. Thomas Jefferson told us” adding “The science is on our side on this one”.
Third, the preoccupation of suburbia international with economic issues. Until people fully understand the implications of runaway climate change, government actions are likely to be restricted within the context of the virtual reality of economic boom-bust bubbles, where greed and fear obscure the physical realities of the environment and of agricultural food production, a consequence of over 60 years of commercial propaganda rendering populations victims of ruthless vested interests at the expense of future generations.
The Wilkins ice shelf collapse is but the latest symptom of fast-melting polar ice. Last year was the first during which the huge (13,680 square kilometers) shelf, which bridges the West Antarctic peninsula with the Charcot and Latady islands, developed fractures during mid-winter [27]. Now advanced Synthetic Aperture Radar (ASAR) images acquired on 2 April, 09, by the European Earth Observation (ESA’s) Envisat satellite confirm the ice shelf is collapsing into thousands of ice bergs [28], removing the barrier for the flow of continental glaciers into the ocean.
It is likely only a combination of deep urgent cuts in carbon emissions, coupled with major investments in fast-tracked development of a wide range of effective geo-engineering methods may be capable of making the difference.
