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When you see a picture of a dinosaur, it is generally in a hot damp swamp
with dense dark clouds and a couple of volcanoes erupting in the background.
This is what scientists think the earth looked like because intense volcanic
activity was sending large amounts
 of greenhouse gas into the atmosphere. The
planet was covered with dense clouds and the atmosphere contained a high
concentration of carbon dioxide, producing tropical conditions north of the 45th
parallel. For example, many dinosaur fossils were excavated in Alberta, Canada.
As the earth's crust cooled down, volcanic activity reduced.
The process of life collects carbon dioxide in organic material and covers it
with sediment, in effect taking it out of the atmosphere and storing it in the
ground. Over many years the pressure and heat underground turned this organic
material into coal, gas and oil. So after millions of years of this process, we
get the atmosphere and climate of today. Our climate is not better or worse than
in these ancient times (the dinosaurs liked it), it is just different. However,
in a very short time (on a geologic time scale) our technologically intensive
way of life has emerged and is, unfortunately, finely tuned to today's climate.
With less rain, our dams would stop producing electricity, and our agricultural
yield would be insufficient to feed our large population. With more rain, the large
cities built on fertile plains would be flooded. The cost to our society with
such climate changes would be astronomic.
Until recently, it was believed that the climate can shift only very slowly
over thousands of years and that our society can adapt to such a slow change
relatively painlessly. Yet, we are now pumping and digging all that carbon
dioxide from the ground at a rate of 25 billion tonnes per year to satisfy our
energy needs. By burning these fossil fuels, we return the carbon dioxide back
to the atmosphere. At this rate, we will extract all of the carbon from the ground
within a few hundred years, which is a very small time in geological terms. The
pre-industrial carbon dioxide concentration in the atmosphere was 250 parts per
million. Today it is 350 ppm and increasing at a rate of 5 ppm/year. If we keep
going at the present rate it will be 900 ppm by 2100, more than triple the
pre-industrial level. Scientists are still arguing about how much climate
warming this will create and the consequences of it, but even with the most
optimistic calculations it will be a big mess!! Sea levels will rise from
melting glaciers and polar caps, flooding low lying areas. The weather will be
more extreme, creating drought, storms, tornadoes, cyclones, etc. There will be
a high cost and great pain to our society in adapting to these rapid changes of
climate. In facing these dire predictions, governments around the world are trying
to react by reducing fossil fuel consumption. Many countries, (except, notably, the US, that uses ¼ of the world's
energy), have signed the Kyoto accord. Some estimates of the cost of meeting these reductions are extremely
high. In Canada alone, for example, the estimated cost is $40 billion/year, and such
a cost could produce an economic recession. Many less developed countries with
huge populations are now starting economic growth. What will happen when many
citizens of China and India start driving large SUV's like in the US? Maybe the developed
world will try to impose environmental regulations on the developing countries
to prevent these nations from doing what the developed countries have been doing
for years? This will probably not happen and the earth will not be able to
support such a further increase in fossil fuel consumption and emissions.
Luckily for the planet, but rough on the economy, fossil fuel will
eventually become harder and harder to find until it is uneconomical to use. But
maybe, by then, the damage to our ecosystem will already be too severe.
We are heading straight into a major energy, environmental and economical
crisis. Something new has to happen, and it needs to happen soon if
irreversible damage to the life-support system of our planet is to be avoided.
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