Droughts, floods, hurricanes, forest fires and other extreme weather conditions are nothing new. Claims that they have become more frequent or more sever due to climate change are very difficult to verify scientifically. By definition, an extreme weather condition occurs infrequently, but the statistical distribution does not follow the normal ‘bell shaped’ curve, but the shape known mathematically as the chai-squared distribution, which has a very long tail, hence one needs a very long period to measure the average frequency of any extreme event. It is also very easy to select a shorter period, say 15 years in which the frequency exceeds or falls below the average. To determine if there are, say more hurricanes than in the past, one needs to cover a very long period. In fact statistical studies over a long enough period to be scientifically significant do not show any increase in either frequency or severity. However unless one can show that climate change is a problem, millions of climate scientists would be out of a job!
CO2 is a greenhouse gas, not the only one, and not the most significant one. Water vapor is the most important for protecting the planet from another ice age. However higher CO2 is definitely associated with a slightly warmer climate. In the carboniferous era, about 350 million years ago, CO2 concentrations were about 1500 ppm (parts per million) and average temperatures were about 22 degrees C. Ferns and other plants grew proliferously, because plants love a warm and high CO2 environment. This abundant plant growth got buried and formed the fossil fuels we use today. Since the industrial revolution, when we started burning coal to create the energy that the new machines needed, CO2 rose from about 300 ppm to the 425 ppm we enjoy today.
Which goes a long way to explain why crop yields today are higher than in the past; this is true world-wide, not just for Canada. It’s true for undeveloped countries also. CO2 is a blessing not a curse. Obviously better methods and genetically improved plants have also helped, but that’s far from whole story. Greater yields and mechanized farming is why food is so cheap today, and why famines are no longer a threat except when caused by war.
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