It was only a couple of days ago that Anthony Watts asked for feedback and one of his readers leftturnandre wrote:
June 15, 2014 at 8:34 am
Got only a second now, but the very first thing that comes into mind: don’t allow fallacies. Don’t go down to the level of the opposition. Keep on the high grounds.
Anthony Watts builds a straw man
Anthony didn't listen. Today he's built a strawman fallacy, writing:
One of the favorite boogeyman arguments used in climate alarmism is that climate has been stable for thousands of years, and that our recent industrialized era emissions will result in climate tipping point. However, this study in the Proceeding of the National Academies of Science suggest that climate disruption caused people in the Central Andes to migrate to find a better climate over a thousand years ago.That's a strawman fallacy because he's misrepresenting the science just so he can tear it down. It's not that local climates haven't changed. It's that overall the world has, until now, had relatively little change since human civilisation began. Much less than what's to come. It's also quite silly because he's calling on that same science to show that climates have changed in different parts of the world at different times. So which does he believe? Climate science or climate science? His poor little brain must be doing cartwheels.
Is Anthony Watts now a greenhouse effect denier?
Anthony jumps to another logical fallacy in his second paragraph, writing:
This posited bout of climatic fluctuation occurred before anyone knew what carbon dioxide was. So what was the driver then? Surely it wasn’t CO2 levels, which according to James Hansen and Bill McKibben who say“safe” levels are below 350 parts per million, which according to this graph from CDIAC, was below 300ppm during the period of study.
This time he's arguing that climate science attributes all climate change to a change in atmospheric carbon dioxide. He's implying that because droughts in what is now Peru in the relatively recent past (geologically speaking) weren't caused by a change in atmospheric CO2, then the current global warming can't be caused by increased CO2.
It looks as if Anthony Watts has become a greenhouse effect denier - which at other times he's denied.
Climate migrations in pre-Columbian southern Peru
Although the stray WUWT-er might think it, going by Anthony's silly lead in, the paper itself is not new climate science. These climate events have been known about for quite a long time. What it is presenting is evidence of human migration as a result of those climate changes. It's an anthropological study by a large team led by Lars Fehren-Schmitz of the University of California Santa Cruz.
Some of the paper is described at Phys.org:
To gain a clearer understanding of early Nasca, Wari and Tiwanaku peoples living in various parts of what is now Peru, the researchers collected DNA samples from 207 mummies found in both coastal and mountainous parts of the region. Mitochondrial analysis and Bayesian modeling indicated that people that had been living near the coast began migrating to the mountains sometime around 640 BC. They also found evidence of a reverse migration as people from the mountains migrated towards the coast around 1200 AD.
From the WUWT comments
Like Anthony Watts, many of the deniers at WUWT are not able to differentiate between local climate change and global climate change.
June 18, 2014 at 10:28 am
climate science 101. any climate change that can’t be attributed to humans must be due to volcanoes. we can tell how big the volcanoes must have been by how much climate change there was. In this case a big volcano must have started erupting in ∼640 AD and ended in ∼1200 AD. the cannot be connected to the medieval warm period, because this change in south America, as well as the change in Europe, even thought they were at similar times, were both only regional. global changes only occur when humans are involved.
Alan Watt, Climate Denialist Level 7 is very wrong when he says:
June 18, 2014 at 10:26 am
So maybe these were really the “first climate change refugees” ?
TAG demonstrates a brain that works some of the time at least, and says:
June 18, 2014 at 10:33 am
Since the Little Ice Age in Europe was coincident with the 30 Years War, these findings should not be unexpected. The 30 Years War ended with the Treaty of Westphalia. This treaty created the concept of the sovereign nation state which shapes our world today. So it is no surprise that climate change can have dramatic and long lasting political and societal effects.
One thing that we should all remember the CO2 or not, climate plays an important part in our history and that even relatively slight climate changes can have large effects. natural variability can drive the course of history fro centuries. Don’t let the hype from climate activists and third team activist scientists distract us from this fact.
Chris B is a good little WUWT denier and says:
June 18, 2014 at 10:59 am
I’d like a couple million and a super computer to find out where all the SUV’s and coal plants went.
Pathway is also scoring brownie points from Anthony Watts and says:
June 18, 2014 at 11:01 am
If it doesn’t fit the agenda it is irrelevant.
Lars Fehren-Schmitz, Wolfgang Haak, Bertil Mächtle, Florian Masch, Bastien Llamas, Elsa Tomasto Cagigao, Volker Sossna, Karsten Schittek, Johny Isla Cuadrado, Bernhard Eitel, and Markus Reindel. "Climate change underlies global demographic, genetic, and cultural transitions in pre-Columbian southern Peru", doi: 10.1073/pnas.1403466111