As previously pointed out on this list, monsoon disruption and ocean acidification are not widely accepted as being the certainties claimed below.
A On Feb 18, 2013 6:13 PM, "Rau, Greg" <[email protected]> wrote: > http://www.skepticalscience.com/print.php?n=1785 No alternative to > atmospheric CO2 draw-down > > This article suggests that the current atmospheric CO2 level is already > triggering amplifying feedbacks from the Earth system and therefore, in > themselves, efforts at reduction in atmospheric CO2-emission are no > longer sufficient to prevent further global warming. For this reason, along > with sharp reductions in carbon emissions, efforts need to be undertaken in > an attempt to reduce atmospheric CO2 levels from their current level of > near-400 ppm to well below 350 ppm. NASA-applied outer space-shade > technology may buy time for such planetary defense effort. > > The scale and rate of modern climate change have been greatly > underestimated. The release to date of a total of over 560 billion ton of > carbon through emissions from industrial and transport sources, land > clearing and fires, has raised CO2 levels from about 280 parts per > million (ppm) in pre-industrial periods to 397-400 ppm and near 470 ppm CO > 2-equivalent (a value which includes the CO2-equivalent effect of > methane), reaching a current CO2 growth rate of about 2 ppm per > year<http://www.globalcarbonproject.org/> > > *Figure 1: Part A. Mean CO2 level from ice cores, Mouna Loa observatory > and marine sites; Part B (inset). Climate forcing 1880 - > 2003<http://pubs.giss.nasa.gov/abs/ha06510a.html>. > Aerosol forcing includes all aerosol effects, including indirect effects on > clouds and snow albedo. GHGs include ozone (O3) and stratospheric H2O, in > addition to well-mixed greenhouse gases.* > > *Figure 2: Relations between CO2 rise rates and mean global temperature > rise rates during warming > periods<http://cci.anu.edu.au/files/download/?id=4951> > *, including the Paleocene-Eocene Thermal Maximum, Oligocene, Miocene, > glacial terminations, Dansgaard-Oeschger cycles and the post-1750 period. > > These developments are shifting the Earth's climate toward Pliocene-like > (5.2 - 2.6 million years-ago; mean global temperatures of +2-3oC above > pre-industrial temperatures) and possibly toward mid-Miocene-like > (approximately 16 million years-ago; mean global temperatures +4oC above > pre-industrial > temperatures<http://www.nature.com/ngeo/journal/v4/n7/fig_tab/ngeo1186_ft.html>) > conditions within a few centuries--a geological blink of an eye. > > The current CO2 level generates amplifying feedbacks, including the > reduced capacity of warming water to absorb CO2 from the atmosphere, CO2 > released > from fires, droughts, loss of vegetation cover, disintegration of methane > released from bogs, permafrost and methane-bearing ice particles and > methane-water molecules. > > With CO2 atmospheric residence times in the order of thousands to tens of > thousands > years<http://www.pnas.org/content/early/2009/01/28/0812721106.abstract>, > protracted reduction in emissions, either flowing from human decision or > due to reduced economic activity in an environmentally stressed world, may > no longer be sufficient to arrest the feedbacks. > > Four of the large mass extinction of species events in the history of > Earth (end-Devonian, Permian-Triassic, end-Triassic, K-T boundary) have > been associated with rapid perturbations of the carbon, oxygen and sulphur > cycles, on which the biosphere depends, at rates to which species could > not > adapt<http://theconversation.edu.au/is-another-mass-extinction-event-on-the-way-5397> > . > > Since the 18th century, and in particular since about 1975, the Earth > system has been shifting away from Holocene (approximately 10,000 years to > the pre-industrial time) conditions, which allowed agriculture, previously > hindered by instabilities in the climate and by extreme weather events. The > shift is most clearly manifested by the loss of polar > ice<http://www.agu.org/pubs/crossref/2011/2011GL046583.shtml>. > Sea level rises have been accelerating, with a total of more than 20 cm > since 1880 and about 6 cm since > 1990<http://www.eea.europa.eu/data-and-maps/indicators/sea-level-rise-1/assessment> > . > > For temperature rise of 2.3oC, to which the climate is committed if sulphur > aerosol emission discontinues<http://pubs.giss.nasa.gov/abs/ha06510a.html> > (see > Figure 1), sea levels would reach Pliocene-like levels of 25 meters plus or > minus 12 meters, with lag effects due to ice sheet hysteresis (system > inertia). > > With global atmospheric CO2-equivalent (a value which includes the effect > of methane) above 470 ppm, just under the upper stability limit of the > Antarctic ice > sheet<http://www.columbia.edu/~jeh1/2008/TargetCO2_20080407.pdf>, > with current rate of CO2 emissions from fossil fuel combustion, cement > production, land clearing and fires of ~9.7 billion ton of carbon in > 2010<http://www.science.org.au/natcoms/nc-ess/documents/GEsymposium.pdf>, > global civilization faces the following alternatives: > > 1. With carbon reserves sufficient to raise atmospheric CO2 levels to > above 1000 > ppm<http://www.columbia.edu/~jeh1/mailings/.../20120130_CowardsPart2.pdf>, > continuing business-as-usual emissions can only result in advanced melting > of the polar ice sheets, a corresponding rise of sea levels on the scale of > meters to tens of meters, on a time scale of decades to centuries, and high > to extreme continental temperatures rendering agriculture and human > habitat over large regions > unlikely<http://www.ccrc.unsw.edu.au/staff/profiles/sherwood/wetbulb.html> > . > 2. With atmospheric CO2 at about 400 ppm, abrupt decrease in carbon > emissions may no longer be sufficient to prevent current feedbacks > (melting of ice, methane release from permafrost, fires). Attempts to > stabilize the climate require global efforts at CO2 draw-down, using a > range of methods, including global reforestation, extensive biochar > application, chemical CO2 sequestration (using sodium hydroxide, > serpentine and new innovations) as well as burial of > CO2<http://www.science.org.au/natcoms/nc-ess/documents/GEsymposium.pdf> > . > > As indicated in Table 1, the use of short-term solar radiation shields > such as sulphur aerosols cannot be regarded as more than a band aid, with > severe deleterious consequences in terms of ocean acidification and > retardation of the monsoon and of precipitation over large parts of the > Earth. > > By contrast, retardation of solar radiation through space sunshade > technology <http://www.sciencedaily.com/releases/2006/11/061104090409.htm> may > allow time for CO2 draw-down. Unlike sulphur dioxide injections this will > not have ocean acidification effects - an effort requiring a planetary > defense project by NASA. > > Dissemination of ocean iron > filings<http://newswatch.nationalgeographic.com/2012/10/18/iron-fertilization-savior-to-climate-change-or-ocean-dumping/> > aimed > at increasing fertilization by plankton and algal blooms, or temperature > exchange through vertical ocean pipe > systems<http://www.realclimate.org/index.php/archives/2007/04/ocean-cooling-not/>, > are unlikely to constitute effective means of transporting CO2 to > relatively safe water depths. > > By contrast to these methods, CO2 sequestration through fast track > reforestation, soil carbon, biochar and possible chemical methods such as > "sodium > trees"<http://www.realclimate.org/index.php/archives/2007/04/ocean-cooling-not/> > and > serpentine (combining Ca and Mg with > CO2<http://onlinelibrary.wiley.com/doi/10.1002/cjce.5450810373/abstract>) > may be effective, provided these are applied on a global scale > > Such efforts will require an effective planetary defense effort on the > scale currently expended on military spending (totaling more than $20 > trillion since WWII). > > It is likely that a species which decoded the basic laws of nature, split > the atom, placed a man on the moon and ventured into outer space should > also be able to develop the methodology for fast sequestration of > atmospheric CO2. The alternative, in terms of global heating, sea level > rise, extreme weather events, and the destruction of the world's food > sources is unthinkable. > > Good planets are hard to come by. > > Posted by Andrew Glikson on Thursday, 14 February, 2013 > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/geoengineering?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
