Slashdot Mirror
Columbus Blamed For Mini Ice Age
DesScorp writes "Science News reports on a story which blames a centuries long cooling of Europe on the discovery of the new world. Scientists contend that the native depopulation and deforestation had a chilling effect on world-wide climate. 'Trees that filled in this territory pulled billions of tons of carbon dioxide from the atmosphere, diminishing the heat-trapping capacity of the atmosphere and cooling climate, says Richard Nevle, a geochemist at Stanford University.' The story notes that the pandemics in the Americas were possibly an example of human climate manipulation predating the Industrial Revolution, though isotope measurements used during research have much uncertainty, so 'that evidence isn't conclusive.'"
It should say "the native depopulation and consequent re-forestation" rather than "native depopulation and deforestation". In current models, it doesn't make sense that deforestation leads to cooling.
- First, this is all predicated on Europeans moving on a massive scale to the Americas. The author writes "By the end of the 15th century, between 40 million and 80 million people are thought to have been living in the Americas." Given that Columbus sailed in 1492, does anyone seriously believe tens of millions of Europeans moved to the Americas in the next 8 years? Even in the next 100 years? Completely nonsensical numbers.
The 40-80 million population refers to the natives, not the settlers.
- Third, they got the direction wrong: if forests were chopped down, they would have been burned and not allowed to regrow - thus increasing CO2, not decreasing it.
If you read the article, you;d know that the effect is due to the growth of trees in cleared areas, not the burning of trees that occurred prior to that.
does anyone seriously believe tens of millions of Europeans moved to the Americas in the next 8 years?
No, people do seriously believe the European invasion killed off millions of indigenous people, who, after dying, stopped their agricultural activities, which allowed forests to regrow, which sucked CO2 out of the atmosphere.
This paper contends that that decrease in CO2 cooled Europe.
From TFS: "Tying together many different lines of evidence, Nevle estimated how much carbon all those new trees would have consumed. He says it was enough to account for most or all of the sudden drop in atmospheric carbon dioxide recorded in Antarctic ice during the 16th and 17th centuries."
So yes.
http://en.wikipedia.org/wiki/Year_Without_a_Summer
http://en.wikipedia.org/wiki/1815_eruption_of_Mount_Tambora
Earlier midmillenial cool downs were due to a volcano in Iceland and other solar minimums as well.
Look, I'm infuriated by climate change denying morons myself, but rewriting history and ignoring basic science is not how you defeat those losers. Simple repetition of obvious scientific facts about man made warming is how you defeat oil and coal industry propaganda kool aid drinkers, not reimaging the plot of "Avatar."
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
This is a roundup of a lot of scholarly work on what the Americas were like before Columbus. In short, the book contends that there were an awful lot of people in North America prior to the Age of Exploration who were extraordinarily susceptible to European diseases. While many practiced straight-up agriculture, a lot of others essentially "farmed" wild game - early European colonists into the Ohio Valley noted that the land often looked like European parks (i.e., trees spaced far enough apart that wagons could easily be driven between them, with occasional copses, making perfect habitat for deer), and that an extraordinarily high percentage of the trees that were there were nut-producers (i.e., they planted those and cut down anything else). It also argues that the early explorers (especially de Soto's expedition) weren't making things up when they talked about cities with tens of thousands of inhabitants lining the sides of rivers. When they died en masse, the "old-growth" forests arose.
You can see such a dip in the first graphic associated with this paper:
http://cdiac.ornl.gov/trends/co2/lawdome.html