[Illustrations, footnotes and references available in PDF version]
Knowledge of the past is extremely important when it comes to contemplating future climatic possibilities; for what's happened before can clearly happen again. Hence, this summary briefly reviews the history of Canadian droughts with respect to how they varied over the past several centuries in response to significant changes in global air temperature but very little change in the atmosphere's CO2 concentration, which exercise provides some idea of how Canadian droughts might possibly vary in the post-Little Ice Age world that is known as the Current Warm Period.
There is no solid evidence to conclude that climatic warming, if it occurred, has caused the Prairie drought to become more severe.
It is clear that 20th century warming, if anything, has led tomore stable climatic conditions with fewer hydrologic extremes (floods and droughts) than was typical of prior Little Ice Age conditions.
Hydro-ecological conditions after 1968 have remained well within the broad range of natural variability observed over the past 300 years, with the earlier portion of the record actually depicting "markedly wetter and drier conditions compared to recent decades."
In summation, and in view of the numerous similar findings from across a wide and varying geographic area, it would appear that much of Canada has (1) experienced less-variable extreme moisture conditions, as both it and the rest of the world have emerged from the relative cold of the Little Ice Age and are now basking in the greater warmth of the Current Warm Period, and that (2) this finding appears to be independent of the atmosphere's CO2 concentration.
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