On 26/02/10 06:53, Claudius Denk wrote:
British Hadley Centre scientists said last year that there was no
warming from 1999-2008, after allowing for extreme, natural weather
patterns. Temperatures should have risen by a widely estimated 0.2
degrees Centigrade, given a build up of manmade greenhouse gases.
Perhaps there's no warming in their dataset because it's not global? It
could also be a result of their smoothing method. It may be more
scientifically correct than my 11-year running mean but might it have a
bias towards the latest years? In my graph, although there has been a
slight dip in the early noughties (the latest year to have a full
11-year span is obviously 2004), similar dips show up in the curve in
the mid-90s, the mid-to-late 80s and the late 70s. It looks like a 7-8
year cycle, not that I put much faith in cycles - I keep falling off them.
"Solar might be one part of it," said the Hadley's Jeff Knight, adding
that changes in the way data was gathered could be a factor, as well
as shifts in the heat stored by oceans.
The sun goes through phases in activity, and since 2001 has been in a
downturn meaning it may have heated the earth a little less,
scientists say.
Another comparison I've done with graphs of sunspot activity and global
temperatures shows little correlation. During the rise in global
temperature from 1890-1940, sunspots were below the long-term average
until about 1935. During the slight dip in temperatures from 1940 to
1970, sunspot activity was high and reached a record level in the cycle
that peaked in the late 50s.
Judging by past events, if we're heading for a low sunspot period, look
out for rapidly rising global temperatures! ;-)
"We've not put our finger precisely on what has changed," Knight said.
"(But) If you add all these things together ... there's nothing really
there to challenge the idea that there's going to be large warming in
the 21st century."
Melting Arctic ice was evidence for continuing change, regardless of
observed temperatures, said Stein Sandven, head of the Nansen
Environmental and Remote Sensing Center in Norway.
"The long-term change for the Arctic sea ice has been very consistent.
It shows a decline over these (past) three decades especially in the
summer. In the past 3-4 years Arctic sea ice has been below the
average for the last 30 years."
And the average for the last 30 years is below the average for the
previous 30 years.
Trenberth attributed the cold winter to an extraordinary weather
pattern not seen since 1977 which had curbed prevailing westerly winds
across the northern hemisphere, and said that the underlying cause was
"one we don't have answers to." (For Reuters latest environment blogs,
click on: http://blogs.reuters.com/environment/)
Oh for pity's sake! We have the answers and have had them for fifty
years. SST anomalies! Don't these so-called scientists do any research?
Mind you, as always, do we have the answers to the answers?
--
Graham P Davis, Bracknell, Berks., UK. E-mail: newsman not newsboy
"I wear the cheese. It does not wear me."