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What is global warming?
Global warming is caused by the build up of so called 'greenhouse' gases in the atmosphere.
The gases are so called because they work exactly like a greenhouse. They let the visible
sunlight in which warms the Earth's surface but reflect back to Earth the invisible infrared
given off by the warm surface, thereby keeping the surface warmer than it otherwise would be.
The higher the concentration of greenhouse gases, the greater will be the greenhouse effect
and the higher the average global temperature will be. The greenhouse gas of most concern at
the moment is carbon dioxide (CO2) but methane and water vapour are also greenhouse gases.
Is the crisis real?
The short answer is yes. The crisis is real enough, what we don't know is how bad it will get. But as the
scientist's findings mount, the worse the best case scenarios look and the more likely the worse case
scenarios become.
The extent our pollution is contrubuting to higher temperatures could be much less than we
think - or it could be much more. Recently it was discovered that particulate matter (another
polutant produced by internal combution engings) was causing clouds to reflect more sunlight
back into space. This was having the opposite effect and cooling the Earth.
What is scary about this discovery is that as everyone knows, two wrongs don't make a right and anyone who
thinks otherwise will get a nasty lesson sooner or later. What it tells us in scientific terms is that the
effect on temperature of rising carbon dioxide concentrations from about 320 parts per million in 1960 to
about 380 parts per million today, is much greater than previously thought. Going forward the effect of
future rises in CO2 will not be mitigated by clouds reflecting more sunlight as particulate pollution is
falling due to higher emission standards and cleaner burning engines. Temeratures will likely soar not by
the 2 or 3 degrees as previously thought, but by anything from 4 to 6 degrees. The answer is clearly to
lower carbon emissions by burning less fuel rather than dirtier engines!
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