Geoscience Reference
In-Depth Information
Plate 28.1
The addition of moisture and pollution from aircraft engines can lead to condensation trails in the upper atmosphere.
They are often most persistent where the atmosphere is close to saturation already as shown by the extensive cirrostratus
the long-wave loss from the surface and atmosphere (leading to warming). It is believed the latter effect is dominant.
Photo: Peter Smithson
parts of Earth (
Chapter 6).
Not surprisingly, therefore, all
models show a continuation in ENSO affecting large parts
of the globe. Unfortunately the models do show much
variety in predictions of the interannual changes in the
magnitude of events. As a result it is impossible to predict
with any confidence what may happen to future ENSO
events in terms of their magnitude.
At a more local scale there is much concern about
whether global warming will affect the frequency, intensity
and tracks of tropical cyclones. Any future change in the
properties of tropical cyclones could have major socio-
economic impacts; storms are important as sources of
water as well as for the damage, and even death, they can
cause. As with the monsoon systems and ENSO, we are
largely dependent upon modelling, with the added
problem of scale; tropical cyclones are much smaller-scale
atmospheric features than the previous two. Fortunately,
we have a historical record of how tropical cyclones of the
Atlantic Ocean have changed over time and to some extent
how these relate to oceanographic and atmospheric
factors. Work published in the Philosophical Transactions
of the Royal Society (2007) suggests the frequency of
hurricanes has increased, presumably because of the
warmer sea-surface temperatures. This idea is supported,
to some extent, by the IPCC report, which indicates that
models predicted a
decrease
in the number of storms but
an increase in the number of the most intense storms.
Although there are many uncertainties in our efforts
to model future climates, there is some consensus about
global warming, but much still remains to be done to
determine what impacts this might have on regional and
local scales of climate. As well as climate itself, global
warming is likely to affect other aspects of the physical
environment, and we will now examine some of these.
