contrails

Being a bit touchy aren't we Tom? If you want to present AGW/Climate
Change as a religion (which it seems to have become), then I am
neither a believer or a disbeliever (denialist), but an agnostic. The
latest data on World temperatures, which show a slight cooling, do not
correlate with the theory, so that is why.

Not according to people who actually track that sort of thing:

http://www.ncdc.noaa.gov/sotc/?report=global#gtemp

Possibly you were thinking of data sets that begin with the El Nino
event of 1998-99?

If you use that as your starting point then it biases the result to
show
fairly flat temperatures from 1998 - 2008, just like you could use it
to exaggerate increasing temperatures from 1989 1999.

I think some people call that 'cherry picking' the data.

For myself, I don't put much stock in the currently available database
of direct temperature measurements, and less stock in proxies. In
both cases the sampling problem looms large.

I do trust the measurements of atmospheric gases from Mauna Loa
and the measurements of solar activity. Those are much easier to
sample.

If one does accept direct temperature measurement and pre-Mauna
Loa atmospheric gas measurements and proxies like these:

http://en.wikipedia.org/wiki/File:In...ure_Record.png

What we see is a temperature rise of ~ 0.7 degrees Celsius during the
20th century.

One can explain that as follows:

Temperatures rose quickly at the end of the 19th century due
to methane released by oil exploitation (early on there was no
market for natural gas so gas wells were typically left uncapped).
As methane has a fairly low half life in the atmosphere (12 years)
temperatures dropped quickly until 1910 or so at which point
carbon emissions from industrial growth caused a continuous
rise through WWII.

Then very rapid industrial growth and coal burning in particular,
especially to power the world's electrical grids loaded the
atmosphere with aerosols that offset the increased greenhouse
effect of the concurrently released carbon dioxide until pollution
abatement came into vogue in the 1970s. This pollution abatement
concentrated on particulates and sulfur compounds, but ignored
carbon dioxide.

As particulates continued to drop out of the atmosphere and
carbon-dioxide rose so did temperatures from then until now,
with a noted acceleration after German reunification produced
a cleanup of East German Industry.

Other explanations are possible.

--

FF