Bows and Arrows, and Spears that changed the Climate of the world ...

25 May 2010

At May 23rd ... a paper by 3 researchers published in Nature this week has a novel take on the Younger Dryas event - it was caused by humans killing off herds of mammoth and causing temperatures to drop. This is perhaps the whackiest global warming alarm story of the year and it's hard to accept that it was written in all seriousness - but it must have been as it was published by Nature - and they aren't into comedy. Are they?

The paper illustrates just how scientists can dream up any kind of nonsense and get it published, and just as long as it has a global warming angle it will be rewarded with an appropriate grant. Presumably the paper was peer-reviewed as the more skatty a theory is the more likely it has bilge rats on board ship. Basically, they are saying that mammoths and other large animals of the Pleistocene epoch became extinct 'only after' humans spread across the New World in the few thousand years between the end of the Ice Age and the onset of the Younger Dryas. So, the theory begins by ignoring i) the mass extinction event between 40 and 30,000 years ago, and ii) various other cold spells prior to the YD and within the timescale they have pinpointed - namely, the Older and the Oldest Dryas events (quite apart from the numerous Heinrich events preceding the end of the Ice Age). Anyway, ignoring those little nit-picking points, the argument is that mammoths and other large mammlas in North America (this is American tax-payers money provided to fund the research so it only concerns American fauna), ate a lot of grass and herbs and emitted lots of methane. This greenhouse gas is 30 times more potent than C02 they assure us - but it was not enough to trigger global warming (it was in fact, already warm, much warmer than the Ice Age itself). However, the kill-off by humans of mammoths and other large mammals by bands of stone age hunters was enough, they say, to cause the Younger Dryas cooling event. As such, they take it upon themselves  to crown this incredible piece of junk science by renaming the Holocene the Anthropocene Epoch - picking up another silly idea from another whacky global warming article. The era of human impact on the planet and it's climate system is driven backwards - it is not just motor cars and aeroplanes that change the climate but bows and arrows, and even spears are capable of impacting on our weather. Perhaps the next step is to suggest killing off all the cattle, sheep, pigs and goats on farms around the world - for the greater human good of course.

The same issue of Nature, May 23rd, had another related story - but concerning small animals, in particular rodents such as mice, gophers and squirrels. These animals also declined in large numbers at the end of the Pleistocene (see ) and in this is the double whammy of human hunters and global warming in the Early Holocene (following the YD event) that is blamed for driving species such as mammoths, dire wolves, and short faced bears into extinction. However, the focus of this paper is on the rodents and dimunitive creatures in general. It seems that many of them went into decline but the Deer Mouse was able to take advantage of the situation and expand it's range so that throughou the Holocene it has been the dominant small creature in the western US, having the ability to adapt to a wide range of habitat.

Meanwhile, at is another version of the mammoth extinction marking the YD chill-out. A more thoughtful response can be found on the German blog May 24th and has the title, Mammoth Junk Science, and reports on the numerous mainstream media reports that it was human that hunted and killed off the large mammal herds of the Pleistocene some 13,000 years ago thus causing 'global cooling' - with just spears and arrows as weapons.

The Daily Telegraph assures us that the appearance of humans in North America was responisble for 80 per cent of big mammals vanishing forever, some 114 species in all - yet the journalist has managed to get his sources in a twist. In the Nature paper the extinction happened at the start of the YD event but in the Telegraph they disappeared at the start of the Holocene (at the end of the YD event, some 1300 years later). Gosselin produces a graph that shows temperature over the last 100,000 years - it is full of spikes, ups and downs. He asks, why was the YD cooling caused by humans and all the other downturns in climate during the Late Pleistocene not so? Clearly the graphs shows climate is always changing, often wildly so. Belching mammoths did not drive the YD cooling phase - that idea is junk science.