Apart from the International Panel on Climate Change’s latest report, no one should be surprised that our climate is changing.
It has never been constant.
In the last 2,000 years or so, the Christian era, the earth experienced a warming period between 500 BC and AD 550, the Roman Warm when vines grew in England, then a cool time until about AD 900, followed by the Medieval Warm to 1300, which gave way to the so-called ‘Little Ice Age’ when the Thames froze and Austrian vines died. That ended by 1850.
Now we are in a period of apparently minor fluctuations causing uncertainty about the direction of current change; between 1953 and 1970, as CO2 levels rose temperatures fell.
The longer geological time scales clearly show alternating glacial and interglacial phases, thus change is normal, not exceptional, though it may be slow and almost imperceptible in the short term.
What is surprising, however, is the International Panel on Climate Change’s continuing insistence that global warming results from human activities, particularly the burning of fossil fuels that discharges CO2 into the atmosphere.
There are several problems with this assertion, and it has not been scientifically validated. Emissions have indeed increased in the last few decades but, simultaneously, average global temperatures have fluctuated.
The well-documented Roman and Medieval warm periods happened long before the Industrial Revolution, so burning of fossil fuel cannot have been the cause then. Why should it be the cause now?
Industrial activities are certainly causing such damaging problems as atmospheric pollution, acidification of the oceans and environmental degradation, but these do not cause global climate change.
In geological history, CO2 levels have sometimes been much higher than they are now and, at those times, plant and animal life burgeoned; when CO2 concentrations were low, activities were reduced.
Such variations were completely independent of human activity.
Carbon is an absolute requirement for life as we know it, and so some increase in atmospheric carbon should be welcomed; why do greenhouse operators introduce additional CO2 into their buildings if not to enhance plant growth and productivity? Why, then, should an increase in atmospheric CO2 be cause for alarm?
Another problem is measurement; what, exactly, is being measured and where?
Initially, atmospheric CO2 concentration was determined by the Pettekofer chemical technique, more recently a more efficient infra-red method has come into use. The two methods don’t always give similar results, so that comparisons between data from different times and methods have no validity.
For example, in the late 1950s, readings taken in Hawaii and in Antarctica by the infrared technology gave much lower results than simultaneous readings in Europe by the Pettekofer method; which data set was correct?
There was no correlation between CO2 concentration and temperature during these years. We should treat the presented data with a measure of skepticism.
None of the uncertainties can lead anyone to deny that our climate is changing, but we must remain open-minded about the causes of change; solar effects are the most plausible reason allied to elliptical orbits, tilting of the earth’s axis and precession.
We can no more halt climate change than King Cnut could stem the tides, so such slogans as “Stop Global Warming” are meaningless. Our real challenge is to remain adaptable, flexible and able to adjust and respond to whatever new weather patterns develop as the climate changes. Have we tripped over a false premise and tumbled to an erroneous conclusion?
Dr. Roy Strang writes monthly for the Peace Arch News. rmstrang@shaw.ca