Some days you just have to shake your head and say to yourself that there’s irrational fixation on CO2 that has deep roots in the psyche when we see things like this. The 10:10 video was proof enough, but now we have “paleoblameatology” entering the picture to explain the Little Ice Age.
Meet Christopher Columbus, who had his day this week, but who has gone in the same week from being lauded explorer to destroyer of Europe’s climate by being a catalyst. From Stanford via Science News, of all places.
It boggles the mind.
Here’s the “logic”:
By the end of the 15th century, between 40 million and 80 million people are thought to have been living in the Americas. Many of them burned trees to make room for crops, leaving behind charcoal deposits that have been found in the soils of Mexico, Nicaragua and other countries.
About 500 years ago, this charcoal accumulation plummeted as the people themselves disappeared. Smallpox, diphtheria and other diseases from Europe ultimately wiped out as much as 90 percent of the indigenous population.
Trees returned, reforesting an area at least the size of California, Nevle estimated. This new growth could have soaked up between 2 billion and 17 billion tons of carbon dioxide from the air.
Ice cores from Antarctica contain air bubbles that show a drop in carbon dioxide around this time. These bubbles suggest that levels of the greenhouse gas decreased by 6 to 10 parts per million between 1525 and the early 1600s.
6 to 10 parts per million drop in CO2 triggered the LIA? Seriously? Wow that’s some powerful climate sensitivity. Even the IPCC doesn’t think CO2 is that powerful. Let’s see, since then we added how much? The drop in question is shown below in yellow highlight:
The graph above has this citation in Wikipedia: Law Dome ice cores show lower levels of CO2 mixing ratios during 1550-1800 AD, leading investigators Etheridge and Steele to conjecture “probably as a result of colder global climate”. I suppose Nevle never considered that the oceans might absorb that CO2, perhaps in response to cooling induced by lower solar activity and increased aerosols due to volcanoes.
As for the 6-10 PPM drop induced by Columbus setting off the LIA, maybe such extreme climate sensitivity works in only one direction? /sarc
Mike Smith over at Meteorological Musings sums up this absurdity pretty well:
Mr. Nevle inadvertently makes the case to continue to pump CO2 into the atmosphere. The effects of a Little Ice Age today would be catastrophic given the much larger population of the world. With the shorter growing seasons many millions would starve. The effects of another ice age, little or otherwise, would make global warming seem like a picnic.
h/t to Dr. Ryan Maue