Climate change, which used to be called global warming, is a hot topic (forgive the pun) today – economically, politically and socially – but the debate needs to be more sharply focused. We need to recognize that our climate has never been stable. The last major Ice Age ended about 17,500 years ago. Since then, there has been a general, but fluctuating, warming trend.
In the recent past there was a warm period in Roman times, 2,000 years ago; a Little Ice Age between 1645 and 1715 when England’s Thames river froze over in winter; and warming again between 1930 to 2000. Further back in time, the Earth has endured the Milankovitch cycles of 23,000 and 41,000 years. These fluctuations are reliably associated with changes in sun-spot activity, the Earth’s elliptical orbit, tilt angle change and precession – all quite beyond our control or influence. Trying to halt these natural phenomena is like King Canute’s demonstration to his sycophantic courtiers that he couldn’t stop the tide.
What we can, and should, address is the contribution to global warming made by our Industrial Revolution. By burning fossil fuels we have raised the amount of carbon in the atmosphere from some 280 parts per million (ppm) to close to 400 ppm today. Carbon is essential to plant growth, so much so that greenhouse operators commonly add carbon dioxide to enhance plant growth, but in the atmosphere it traps heat at the Earth’s surface contributing to global warming. One of the indirect effects of increasing CO2 in our atmosphere is a detrimental impact on root activity in the soil, which results in diminished plant growth. It also has the malign effect of acidifying the oceans as well as warming them. It is not as potent a greenhouse gas as methane but there is much more of it.
If warming continues as expected, there will be a consequent rise in sea levels by about one metre by 2100. This will adversely affect 37,000,000 people in the densely populated coastal regions of Bangladesh, China, India, Indonesia and Vietnam, as well as many Pacific islands. In the Caribbean, 229-32 million people are also at risk. A one-metre rise will inundate 37,000,000 square metres and this area could more than double if the sea level rise is three metres, as some scientists predict for 2100. Storm surges associated with such raised levels will worsen the consequences. All around the world, coastal communities and ports will be affected and B. C. is not immune. Delta and Richmond will be at risk, including the airport, and it’s not so long ago that White Rock and its pier suffered severe storm damage and some will remember the 1948 flood.
We have some tools in our arsenal to mitigate the harm. Minimizing, even eliminating, the use of fossils fuels and substituting clean energy sources such as geo-thermal, hydro-electric (though dams are not without problems), nuclear and solar sources; advancing technology for carbon sequestration; preserving or augmenting coastal mangrove forests to minimize the impacts of coastal surges now while there’s still time; erecting sea walls; and learning from the Dutch how to live successfully below sea level. We do have a useful body of knowledge – have we the will to apply it? Besides taking whatever physical or structural measures are feasible, we need to think about succouring millions of displaced and impoverished refugees.
How will we deal with them? We struggle to deal with hundreds or thousands of refugees from Africa and the Middle East now, how will we cope when that number is multiplied tenfold or more?
Dr. Roy Strang writes monthly on the environment for the Peace Arch News. rmstrang@shaw.ca