Antarctic ice breakup makes ocean absorb more CO2
'Global implications for climate research', says US gov
Some cheerful news on the climate change front today, as US government boffins report that ice breaking off the Antarctic shelves and melting in the sea causes carbon dioxide to be removed from the environment. This powerful, previously unknown "negative feedback" would seem likely to revise forecasts of future global warming significantly downwards.
The US National Science Foundation (NSF) which funded the iceberg study, describes the results as having "global implications for climate research".
"These new findings... confirm that icebergs contribute yet another, previously unsuspected, dimension of physical and biological complexity to polar ecosystems," says Roberta Marinelli, director of the NSF's Antarctic Organisms and Ecosystems Program.
A team of NSF-funded scientists examined the effects on an area of the Weddell Sea of a large (20 mile long) berg moving through, melting as it went and diluting the salty sea water - also adding key nutrients carried from the land. They found that after the iceberg had passed, levels of CO2 had plunged and much more chlorophyll was present. Chlorophyll is the substance in green plants which lets them suck in nasty CO2 and emit precious life-giving oxygen: in the Weddell Sea it was present in phytoplankton, tiny seagoing plantoids which are thought to account for half the carbon removed from the atmosphere globally.
The scientists say that more and more icebergs are set to be found in the seas around the Anatarctic as more ice breaks off the shelves attached to the peninsula which reaches up from the polar continent towards South America. This should mean more phytoplankton and thus less CO2.
The iceberg team consider that the increased number of bergs coming from the western Antarctic is the result of warming temperatures in the region, though recent research from British boffins has suggested that in fact other factors may be in play - at least in the case of the Pine Island Glacier, one of the major sources of sea ice in that area.
If the phytoplankton-boosting effect of the bergs is as big as the NSF appears to be suggesting, however, it would seem that any carbon-driven temperature rise could be at least partly self-correcting.
Increased iceberg shedding would seem likely to be seen mainly or only around the western peninsula: antarctic sea ice shelves elsewhere are actually growing, not shrinking, and at such a rate as to outweigh the peninsular losses. The past three decades have seen the south-polar ice sheets grow by 300,000 square kilometres overall.
The NSF study was originally published in the journal Deep Sea Research Part II (subscription required). It was flagged up more recently in Nature Geoscience's top picks (again, subscription link). The NSF also has a statement here. ®
like it'll change anything
All that will happen, as with all anti-CC reports, is that it'll get ignored and we'll continue to get taxed to death.
Nothing stops a well oiled, fast moving gravy train, especially not irrelevancies like "facts".
self correcting mechanism
The self correcting mechanism might be to shed several billion human beings
It gets me that people think the Earth is fundamentally incapable of looking after itself, like some kind of elderly relative.
The fact is that if such balances and controls weren't already in place, we wouldn't be here and the place would be a rock anyway. CO2 has risen and fallen for millions of years and where there's an opportunity for a CO2-thriving mechanism to take advantage, it will do, and will evolve to do so more, until CO2 comes back into line and then *other* mechanisms take over to restore balance the other way. The whole ecosystem is a balancing act and, most importantly, autonomous. Where there's too much CO2, various elements of the biosphere thrive on it and, by bringing about their own starvation of it, restore things to a more "normal" level. Similarly for the complete opposite.
Now, I have no doubt that human activity has an effect, but mostly this effect will only serve to trigger some compensatory mechanism that has kicked in millions of times before in order to restore order. That might mean making the planet (or parts of it) uninhabitable to us, but that's *our* fault. In the end, though, the Earth knows how to look after itself and it's been here a million times before.
When we talk about environmental issues, we never seem to worry about bringing on our own death, and that's really the only threat here... other species have been evolving and/or dying off for millennia and there's virtually nothing we can do about it.
I would be absolutely shocked if, in 50 years time, we discovered that our models of today were anywhere near accurate and modelled reality. I would not be at all surprised by things like this discovery occurring over and over and over again before that.
It doesn't mean we should be throwing our garbage around as easily as we do, but was anybody really *shocked* that there's a self-correcting natural mechanism that compensates for something, which we'd never taken account of?