Scientists used a clever technique to pin down the temperature a thousand years ago during the medieval warm period. The results are both fascinating and a little depressing:
Current TV— The study showed that summertime temperatures on Svalbard were higher now than at any time in the past 1,800 years, including in the Medieval Warm Period from 950 to 1200, scientists wrote in the journal Geology. Summer temperatures were 2 to 2.5 degrees Celsius higher since 1987 than during the Medieval Warm Period, lead author William D’Andrea, a climate scientist at Columbia University’s Lamont-Doherty Earth Observatory, told Reuters.
People sceptical that mankind is the main cause of global warming sometimes point to the Medieval spike in temperatures as evidence that natural variations can bring large climate swings, Columbia wrote in a statement.
“The warming of the past 25 years or so is more than in this record for the Medieval period,” D’Andrea said. The Medieval warming has been linked to shifts in solar output and volcanic eruptions. “It has been pretty well established…that the modern warming is largely due to human contributions of greenhouse gases to the atmosphere,” D’Andrea added.
Two degrees Celsius is a metric shitload. A few years ago I honestly figured climate change wouldn’t seriously disrupt the earth and its fragile network-dependent society on which I depend during my lifetime. Now I just don’t know. The effects seem to be accelerating. Given the usual time scales as opposed to the last decade, it almost seems as though change is now racing wildly out of control. We could be hitting any of a dozen major tipping points today, right now, somewhere, for all I know.
I remember, in the 1960s, seeing a report that humans had significantly increased the CO2 content of the atmosphere. It is now 50 years later, and we know a lot more about the consequences. Yet people are still sitting on their hands and doing nothing.
Yes, it is more than a little depressing.
One of the many reasons I’m glad I’m not having kids.
Jason, are you at all familiar with the issue of ocean acidification? It also looks pretty scary, and may impact the global population sooner than some of the effects of rising temperatures.
http://blogs.kqed.org/newsfix/2012/09/26/scientists-grapple-with-local-impacts-of-globally-acidifying-seas/
Good informative youtube clip here :
http://www.youtube.com/watch?v=CY4Yecsx_-s
by Potholer54 on the whole Medieval Warm Period — fact vs. fiction thing.
Scary reality is we could well already be beyond a climate tipping point because of this.
Of course, anything we can do to mitigate HIRGO* we should do ASAP. The longer we wait, the worse the future consequences and the more drastic the measures we’ll need to fight it.
* Human Induced Rapid Global Overheating
Also for those who don’t already know about it, the state of the Arctic sea ice can be followed here :
http://nsidc.org/arcticseaicenews/
Thanks to the National Snow & Ice Data Center.
On the accelerating rate of change there is another youtube clip* 2011 Arctic Ice Minimum by Peter Sinclair /Greenman3610 esepcially a graph at the 2 minute 25 second mark which shows the models have been too conservative and the observed decline in Arctic sea ice is much more rapid than predicted.
Far from being “alarmist” the climatologists perhaps have been not alarmist enough. Of course the Arctic is being heated more than the rest of our soon-to-aysmetrically- single polar capped globe because of HIRGO but still.
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* Not linked here to avoid this going into moderation.