Geoscience Reference
In-Depth Information
has regional, and indeed global, biological implications that will impact heavily on
human societies. For these reasons there is currently considerable interest in the way
living things interact with the climate, and especially our own species. As we shall
see in the course of this topic, biology, and the environmental sciences relating to
ecology and climate, can provide us with information on past climates and climate
change (palaeoclimatology) which in turn can illuminate policy determining our
actions affecting future climate. This will be invaluable if we are to begin to manage
our future prospects.
1.1 Weatherorclimate
Any exploration of the biology of climate change needs to clarify what is meant by
climate as distinct from weather. In essence, the latter is the day-to-day manifestation
of the former. The climate of a region is determined by long-term weather condi-
tions including seasonal changes. The problem is that weather is in its own right a
variable phenomenon, which is why it is hard to make accurate long-term forecasts.
Consequently, if the climate of a region changes we can only discern this over a long
period of time, once we have disentangled possible climate change from weather's
natural background variability. An analogy is what physicists and engineers refer to
as the signal-to-noise ratio, which applies to electrical currents or an electromagnetic
signal, such as a commercial radio broadcast or that from a stellar body. Similarly,
with climate change, the problem is to disentangle a small climatic change signal from
considerable background weather noise. For example, by itself one very hot summer
(or drought, or heavy monsoon or whatever) does not signify climate change. On
the other hand, a decade or more of these in succession may well be of climatic
significance.
Before we explore climate change and especially current problems, we first need
to be aware of some terms and the phenomena driving current global warming.
1.2 Thegreenhouseefect
The greenhouse effect is not some peripheral phenomenon only of importance to
global warming. The greenhouse effect is at the heart of the Earth's natural climatic
systems. It is a consequence of having an atmosphere, and of course the atmosphere
is where climates are manifest.
The French mathematician Jean-Baptiste Joseph Fourier (not to be confused with
the contemporary chemist of the same name) is generally credited with the discovery
of the greenhouse effect. He described the phenomenon, in 1824 and then again
in a very similar paper in 1827, whereby an atmosphere serves to warm a planet.
These papers almost did not get written because Fourier was very nearly guillotined
during the French Revolution and only escaped when those who condemned him
were ultimately guillotined themselves.
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