Cooling: national geographic, 1976
w...@bas.ac.uk
present the latest addition to my collection:
http://www.wmconnolley.org.uk/sci/iceage/nat-geog-1976-11.html
from the national geographic, 1976.
--W.
--
William M Connolley | w...@bas.ac.uk | http://www.antarctica.ac.uk/met/wmc/
Climate Modeller, British Antarctic Survey | Disclaimer: I speak for myself
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w...@bas.ac.uk
>w...@bas.ac.uk wrote in message news:<4192...@news.nwl.ac.uk>...
>> http://www.wmconnolley.org.uk/sci/iceage/nat-geog-1976-11.html
>One question: according to the graphs of the NAS of that time, the LIA
>was real for the whole NH (as many proxies like bore hole data
>indicate) and a full 1 degr.C below current temperatures. Mann's graph
>seems to be a little too flat against this...
Yes, but Mann's graph it 20 years later. Thats a lot of research. I don't
know what the NAS graphs were based on. By 1990, the IPCC used a
"schematic" for the last 1000 years, which suggests that the NAS 15 years
earlier didn't have anything too quantitative.
>And according to NatGeo "lower temperatures could produce a climate
>generally wetter and less stable, one marked by storms, floods, and
>freezes". Wetter is probably not true, as ice cores in Antarctica
>point to a dryer climate (more dust flowing around), but indeed more
>storms and of course freezes during colder times.
You're probably right. However, (shoulld I have added a caution to the
page?) I didn't post that as an summary of up-to-date science, just what
people were thinking then.
Ice ages are (afaik) generally thought to have been drier, with more
dust (globally?). But that doesn't mean the response has to be linear.
Thomas Palm
> FerdiEgb <ferdinand...@pandora.be> wrote:
>>w...@bas.ac.uk wrote in message news:<4192...@news.nwl.ac.uk>...
>
>>> http://www.wmconnolley.org.uk/sci/iceage/nat-geog-1976-11.html
>
>>One question: according to the graphs of the NAS of that time, the LIA
>>was real for the whole NH (as many proxies like bore hole data
>>indicate) and a full 1 degr.C below current temperatures. Mann's graph
>>seems to be a little too flat against this...
>
> Yes, but Mann's graph it 20 years later. Thats a lot of research. I don't
> know what the NAS graphs were based on. By 1990, the IPCC used a
> "schematic" for the last 1000 years, which suggests that the NAS 15 years
> earlier didn't have anything too quantitative.
The rightmost graph in the article has the text "air temperatures, eastern
Europe". I suspect the other graphs were heavily based on European
temperatures too. It would be odd to use only European data for the most
detailed graph if they had good hemispherical data.
FerdiEgb
Indeed, the latter graph is only based on Eastern Europe data,
probably as these were composed by the Russian contributor to the
story. But the later (1995) composed mid-England temperature
(http://www.env.leeds.ac.uk/envi2150/oldnotes/lecture7/lecture7.html
) roughly has the same form, as does the pre-Mann all-China
temperature reconstruction (see:
http://www.ping.be/~ping5859/china_temp.html . The data disappeared
from the NOAA web site some year ago, but I had them copied).
I suppose that the problem is with the heavy use of tree ring
chronologies by Mann (besides the critique from Esper, that MBH used
an inadequate method to combine short series into long-term trends).
As I have seen several such series (one of the longest was in North
Finland, over more than 7,000 years), it seems to me that tree rings
are dampening real temperature swings, as compared to other types of
proxies.
Ferdinand