We know that rising levels of carbon dioxide are driving climate change. We know the mechanism, we know the statistics, and people all across the world are feeling the consequences in floods, fires, crop failures and migrations. But has CO2 changed the climate before? More pertinently has human meddling with this potent greenhouse gas already unleashed a disaster or so? To our astonishment, some people think it has Stand by for an amazing idea we got from the BBC podcast In Our Time [1] of which more below.
When Columbus sailed to the Americas in 1492 it was not to an empty, underpopulated hemisphere. Both American continents contained thriving populations of agriculturalists. Now, 1492 was indeed the start of huge exchanges of many things-foods, cultures, languages-between Old World and New. But among the earliest and most significant were European diseases like smallpox and measles to which the American populations had no resistance whatsoever. The result was a catastrophic mortality which carried off between 80 and 90% of them.[2] The abandoned farms and croplands quickly reverted to nature. Meaning a sudden massive capture of carbon dioxide which began to cool the planet quickly, leading to the famous Little Ice Age which reached its coldest in the early Seventeenth Century.
And the evidence ? The Little Ice Age is an incontrovertible fact. [3] Ice core samples and climate records indicate the early 17th century as suffering some of the coldest decades in recorded history. But correlation is not cause, as we always say at this blog. Overall, it looks as if the trend towards the dip had started centuries before, and the recovery was still going on centuries afterwards. The cooling may well have been regional rather than global and there is strong evidence to suggest that other factors such as volcanoes and solar cycles may have played their part. However, that CO2 is indeed such a potent greenhouse gas makes its role as a contributor to the Little Ice Age all too plausible. And that is what worries us about levels of the stuff shooting up so dramatically in our own times. Although not proven to the levels of certainty like tigers bite and smoking gives you cancer, we think there is enough here for further research, both by scientists and by you, gentle reader. And now on to our thanks.
Because In Our Time,now presented by the urbane Misha Glenny, is one of the greatest cornucopias of intellectual treasure you will find. gentle readers. By spending an hour in its company once a week you will discover the most eclectic range of fine subjects -Science, History, Art, literature, what have you, all presented by leading experts at Tertiary education level or above(see LSS 9 6 22) In an age where so much media chases sensation over substance, its very existence is a reminder that rationality and intelligence still have a place. And we know we have that on the Highest Authority: read this if you don’t believe us:
Happy is the man that findeth wisdom, and the man that getteth understanding. For the merchandise of it is better than the merchandise of silver. And the gain thereof than fine gold. She is more precious than rubies and all the things thou canst desire are not to be compared unto her
Proverbs 3 12-15
[1] BBC Radio 4 – In Our Time, The Columbian Exchange
[2] Columbian exchange – Wikipedia
[3] Reconciling ice core CO2 and land-use change following New World-Old World contact
#global warming #pandemic #columbus #in out Time #little ice age
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