Environmental Engineering Reference
In-Depth Information
so we need proxies distributed over a wide area of our
world. Tree rings are better than the date of the wine
harvest because we can get tree records from all over,
whereas the wine records are mainly restricted to Europe.
The uncertainties in the temperature derived from each
proxy increase as you go further back from the present.
Nothing in the past
years is like the sharp increase
in temperature that began in the nineteenth century coin-
ciding with the increase in the use of fossil fuels. Natural
processes do not normally change the global average
temperature this fast. The most likely cause is human
activity.
The arguments about the shape of the
“
hockey stick
”
curve of past temperatures discussed in
Section
.
are old
news. Newer and more exciting is the so-called
“
Clima-
tegate scandal
which for a while gave the deniers and the
climate skeptics something to talk about. In November of
”
, emails of the Climate Research Unit (CRU) of the
University of East Anglia in England were hacked. Thou-
sands of communications were taken and released to the
public just before the
global conference in Copen-
hagen that was to lead to more international action to
reduce emissions. The language of some of the emails
seemed to show a bias in the work of the group aimed at
strengthening the case for climate change caused by
greenhouse-gas emissions. Since the CRU was one of
the main keepers of the long-term temperature records,
the non-believers took this as evidence of possible fraud.
The University set up an independent external panel to
look into the situation. The membership was inter-
national, and the members were selected with the help
of the British Royal Society. The panel concluded that
