Hasn't he got this forest stuff backwards? Didn't the European settlers start clearing on a large scale? Didn't that clear cutting put an end to the passenger pigeon?
Anybody on here know the facts? Gene On Oct 16, 2011, at 8:36 PM, Jim Devine wrote: > (by Juan Cole) > Did Columbus Cause Climate Change? > Posted: 15 Oct 2011 09:50 PM PDT > This story is irresistible for a world historian interested in climate > change. Richard Nevle, a geochemist at Stanford, argues that the European > advent in the New World, which killed 90% of the 80 million native Americans, > caused the Little Ice Age. > > The native peoples of the New World burned a lot of wood. When they largely > didn’t exist anymore, because they suffered high mortality from a host of > European diseases to which they had no immunity, they stopped putting carbon > dioxide in the atmosphere. Instead, forests grew rapidly since they weren’t > being chopped down anymore, and land wasn’t being cleared for agriculture. > Forests take in carbon dioxide and exhale oxygen, plus they fix some carbon > dioxide in the soil. They are what is called a “carbon sink,” though not a > really efficient one, since much of the carbon they take out of the > atmosphere eventually finds its way back there. I suspect the dramatic > fall-off in the burning of fossil fuels was the much more important cause > here. > > Less carbon dioxide in the atmosphere reduces the ‘greenhouse effect’ whereby > the atmosphere traps heat generated by sunlight and interferes with it > radiating back out into space. Mars is so cold because it has a very thin > atmosphere and almost no greenhouse effect. But if you get too much carbon > dioxide in the atmosphere, it traps quite a lot of heat, and you get Venus, > where lead runs in molten streams on the surface. The current dumping of > massive amounts of carbon dioxide into the atmosphere by industrial nations > is taking us toward the Venus scenario if it remains unchecked. > > An alternative theory is that reduced solar activity contributed to the > cooling in the 1600s and 1700s. And the warming period of 900-1300 may have > already been reversed in part by the Black Death in Europe and the Middle > East, which wiped out one third of the population and would have reduced > carbon emissions. Of course all these causes could have operated together. > > During the Little Ice age in Britain, people used to go ice skating on the > Thames in the winter. Agriculture was badly hurt by shorter growing seasons, > causing famines and violent competition over resources– i.e. wars and > revolutions. Scandinavia, which had been a major player in world affairs > during the warm centuries 900-1300– ruling Ireland and Sicily (where Vikings > fought Arabs) and discovering North America– rapidly declined in significance > as it froze over. The Ottoman Empire, which threatened Central Europe in the > late 1500s and early 1600s, began being drained by the need to put down the > peasant Celali revolts in the early 1600s in Anatolia, which may have been > climate-related. Famously, there were bread famines in France in the 1780s > that likely contributed to the outbreak of the French Revolution. > > Since the Nile Valley was warmer than Europe (even if less warm in general in > this period) and the river inundated its banks annually, providing natural > fertilizer, Egypt was a breadbasket of the Ottoman Empire and 15% of its > grain probably went to Marseilles in the 1780s and 1790s; the French under > Bonaparte may have decided to conquer it in 1798 in part in order to > monopolize its grain and so solve the problem of repeated famine in France. > In general, the Little Ice Age overlapped with the age of European maritime > empires. The impetus for the Portuguese to take the Indian Ocean, for the > British to venture to India, for the Dutch to go into what is now Indonesia, > may well have been in part to seek new resources at a time of shrinking > European crop yields. > > I want to underline that climate change was only one of multiple causes in > modern history, and sometimes perhaps a minor one. But given that most > societies in the early modern period were agricultural, climate has to be > taken into account. > > The Nevle theory also underlines that human carbon dioxide-spewing activity > has already for some time been important in shaping our climate. That > organisms have changed the earth’s climate is nothing new. Life forms 2.7 > billion years ago began giving us the oxygen in our atmosphere and life has > been one reason the earth did not meet Venus’s torrid fate. Ironically, the > modern human romance with hydrocarbon fuels now threatens this 2 and a half > billion year old success story and is setting us on a slippery slope toward, > ultimately, a Venusian hell. > > > -- > Jim Devine / "In an ugly and unhappy world the richest man can purchase > nothing but ugliness and unhappiness." -- George Bernard Shaw > _______________________________________________ > pen-l mailing list > [email protected] > https://lists.csuchico.edu/mailman/listinfo/pen-l
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