On Oct 22, 9:31 am, Graham P Davis wrote:
Dave Ludlow wrote:
On Sun, 21 Oct 2007 15:06:51 -0700, Scott W
wrote:

...the Hadley Centre for Climate Prediction has come up
against an "inconvenient truth". Its research shows that since 1998
the average temperature of the planet has not risen, even though the
concentration of carbon dioxide in the atmosphere has continued to
increase.

GW crusaders, is that right or wrong?

As to whether 1998 was the warmest year, it depends whose data you believe.
The Hadley data says 1998 but that from NASA says 2005. The problem I have
with the Hadley data is that it only uses areas with data. Now, some (or
many?) might see that as obviously the correct way of using the data.
However, this leads to the area warming the fastest, the Arctic, being
largely ignored.

As I understand their methods, the NASA data is expressed as anomalies and
these are interpolated over data-sparse areas so that the Arctic is
included. I'm not sure whether even this method correctly reflects the
amount of warming over the Arctic. This is an accepted method for dealing
with scattered data, for instance, the Met Office has used it for many
years in producing its SST analyses.

As I've pointed out elsewhere, one could have said in 1998 that the Earth
hadn't warmed in the past 8 years and in 1990 that it hadn't warmed in the
past 9 years.

--
Graham P Davis, Bracknell, Berks., UK. E-mail: newsman, not newsboy.
"What use is happiness? It can't buy you money." [Chic Murray, 1919-85]

The validity of the Hadley data must depend on how large an
area it ignores and what weight is given to the data from sparse
areas. If the area is not too large I would instinctively favour the
NASA method. How large is the difference, anyway?
I don't understand your last sentence. It implies that in
1998 the earth was no warmer than it was in 1990, and in 1990 was no
warmer than in 1981, which cannot be so. Did you mean *since* 1998?

Tudor Hughes, Warlingham, Surrey.