Planet Gore

Climate Cycles

Omniclimate reports on some interesting findings — revealed at last week’s Epica 2008 climate conference in Venice — from a two-mile-deep ice core taken at Concordia Base in Antarctica.

That’s the deepest ice core ever extracted.

The full article by Gabriele Beccaria is available in Italian at this link. Epica 2008 organizer Prof. Carlo Barbante, of University of Venice and Italian National Research Council’s Environmental Process Dynamics Institute, is quoted as saying that the ice core has been taken from

an area where snow accumulates…25 millimeters per year

According to the data, Earth has gone through 8 ice ages and 8 “warm ages” during the past 800,000 years. Barbante says

“we are now in one of the ‘warm’ phases. It started 10,000 years ago and, comparing it to what there’s been [in the past], it can be seen that it’s anomalous, because it has been lasting a long time and temperatures have been very stable”

Still, Beccaria points out that between 120,000 and 100,000 years ago, temperatures have been up to 5C warmer than today’s, at the upper end that is of the IPCC’s more catastrophic scenarios (or predictions). And just 20,000 years ago, the Earth was up to 10C colder (a negative record for the past 800,000 years, apparently). Barbante again:

“The cyclical nature [of temperatures] provides us with the right perspective concerning the climatic changes observed at the moment: if we don’t make the effort towards reaching a better understanding of the natural mechanisms [of climate change], it will be useless to keep trying to patch up predictions on what will happen in a century or two.”

Paleoclimatologists to the rescue then, cajoling to recover at least part of their past relevance after being outclassed by climate modelers as the main reference group able to talk to the politicians.

But there is more (apart from the confirmation of human-related pollution, in terms of methane, nitrogen oxides, chloride, sulfates, nitrates, and heavy metals). Barbante:

“in the core we have measured…the flux of iron in the dust. [Iron] is a biologically-active metal, as it underlies…the conversion of CO2 and nutrients like nitrogen and phosphorus in organic compounds. [We know now that] during glacial intervals iron increases and the biological pump works at its best, whilst during the interglacials like today’s, that process is less efficient and CO2 increases.”

With iron availability near zero at the moment, it is therefore little surprise that CO2 has been increasing, admittedly to record levels compared to the past 800,000 years. In other words it may be not just a matter of human emissions, but also of momentarily-inefficient present-day “carbon sinks”.

Read the rest here.

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