Dr Andrew Glikson from the Research School of Earth Science at the
Australian National University sent a brief submission to Crikey
yesterday. It crunches some sobering numbers:

According to leading US climate and paleo-climate scientists, the
current CO2 levels of 387 ppm (433 ppm CO2 + CH4 equivalent) are
dangerously close to the 450 ppm CO2 level at which the polar ice
sheets formed 34 million years-ago. This projection is consistent with
the current fast ice melt rates in the Arctic Sea, Greenland and west
Antarctica, including melting of the Wilkins ice shelf last July --
one of the first times mid-winter ice shelf breakdown was observed.

The sensitivity of the atmosphere has been underestimated. Ice core
studies of the Pleistocene (1.8 Ma to 11,700 years-ago)
glacial-interglacial cycles display abrupt global warming and cooling
events on time scales of few years to decades, including sharp climate
tipping points at 14,700, 12,900 and 11,700 years-ago.

IPCC climate projections and plans for emission caps restricting
temperature rises to two or three degrees and time tables for carbon
emission reduction targets such as 15 percent by 2020 or 60 percent by
2060, take little account of the rates of ice sheet melt/water
feedbacks loops and carbon cycle feedback loops, including release of
methane hydrates from sea bottom sediments and from bogs.

Plans for climate stabilization at 450 ppm may not be able to prevent
melting of the polar ice sheets. Plans for stabilization at 650 ppm
may not be able to stop runaway greenhouse effects and associated
extinctions.

Today Ross Garnaut has reduced expectations of Australian climate
change action to a point below which anyone other than Andrew Bolt and
a handful of suddenly sweating penguins could object. According to
Garnaut, the best we can hope for is substantial international
cooperation and an aspirational atmospheric carbon target of 450ppm.

550ppm is more likely and looks like being the mark the Australian
Government will pursue. This constitutes surrender ... politically, to
the forces that will rage against any diminution of their capacity to
dig, burn, export and boil, and environmentally to the silent but more
deadly forces that by scientific consensus are placing our eco-system
in almost irreparable peril.

The Garnaut targets mooted today are as clear an indication as any
that our political process seems incapable of delivering the stern
medicine required to arrest climate change, even under the stewardship
of a government elected with a clear mandate to act. They acknowledge
that we will always move first to pursue comfort and compromise. It
looks, sadly, as though we will do that to our cost.