Quote of the weekRichard Treadgold | April 6, 2012
An unimaginable proposal
“As a result — and for reasons that remain unexplained — the waters of the Southern Ocean may have begun to release carbon dioxide.”
Scientific American makes the most illogical statement I’ve heard in a while.
If there’s no reason for this event, why would one propose it?
An event is proposed for which no cause can be imagined. The author proposes something he has no reason to believe — or proposes something but can’t imagine why. This is nuts. It’s not science.
I’d like to read the paywall-defended paper. The abstract in Nature directly contradicts the SA story, saying clearly: “The role and relative importance of CO2 in producing these climate changes remains unclear.”
So how does “Scientific” American justify their subhead? They say:
“The relatively pleasant global climate of the last 10,000 years is largely thanks to higher levels of atmospheric carbon dioxide.”
Is that science or sentiment?
There are other questions. The SA article makes it plain that carbon dioxide concentrations melted most of the ice, explaining that, after the Southern Ocean (may have) released carbon dioxide, raising concentrations by more than 100 parts per million over millennia:
“That CO2 then warmed the globe, melting back the continental ice sheets and ushering in the current climate that enabled humanity to thrive.”
But one of the graphs shown in Nature refers to a 2001 Nature article “Atmospheric CO2 Concentrations over the Last Glacial Termination” using data from the Dome Concordia ice core record that claims an increase in CO2 of 76 ppmv over 6000 years. That’s a long way short of 100 ppmv — where did it come from?
The CO2 concentration near the end of the last glaciation looks to have been around 180 ppmv. Looking at the MODTRAN graph of temperature response to CO2 levels, which drops to a trivial response once it climbs to around 180 ppmv, it doesn’t seem credible that a rise of 100 ppmv, causing a temperature increase of perhaps 0.1 °C, would be enough, even over millenia, to deglaciate the planet.
The researchers acknowledge that other forces were at work. I think it’s obvious the forces were far more powerful than CO2 and the researchers should admit that.