Tuesday, May 29, 2012

It's all so confusing: If the climate has really been so benign and stable for the last 10,000 years, why are we also told that climate change led to the collapse of a civilization around 4,000 years ago?

Climate change wiped out one of the world's first, great civilisations more than 4,000 years ago | Mail Online

Climate change led to the collapse of the ancient Indus civilization more than 4,000 years ago, archaeologists believe.

...Dr Liviu Giosan, a geologist with Woods Hole Oceanographic Institution (WHOI) and lead author of the study, said: 'We reconstructed the dynamic landscape of the plain where the Indus civilization developed 5200 years ago, built its cities, and slowly disintegrated between 3900 and 3000 years ago.

Flashback: Copenhagen: The era of climate stability is coming to an end | Environment | The Guardian

After 400 generations of stable weather, the world is on the brink of violent climate change. But there is good news too

...[Fred Pearce] For about 10,000 years, our climate on Earth has been stable. Remarkably stable, in fact. Since the end of the last ice age, we humans have spent 400 generations taking advantage of this stability to build our civilisation.

We have had warm periods and little ice ages; but the changes have been small. We have always known pretty much when it will rain, what the temperature will be each summer and winter, and how high the rivers will flow.

This benign climate is arguably the main reason why our species has been able to progress


Laurence Crossen said...

It was first correctly understood by climatology that the Holocene climate has been stable compared with glacial climate. For example, the sharp fluctuation known as the Younger Dryas cold spell was 13,000 years ago. By the 1950's it was recognized that climate had fluctuated significantly during the Holocene and the study of the effects of this fluctuation began. This is why students of the effects of climate fluctuations on civilization wonder if any warmists have educated themselves on this subject.

Laurence Crossen said...

More to the point, the question should be, how much of a fluctuation is significant? The answer must be, enough to impact civilization. That much climate change has been happening repeatedly throughout the Holocene.

John said...

The end of the Harappan civilization has been attributed to several causes through time: war, plague, flood, drought, earthquake induced river flow changes, etc. ...

All we are certain of is that it did end and the early excavation work seemed to see evidence of an abrupt end. Enough so that in some locations bodies remained unburied. Indian archaeologists and others continue fling theories at the walls to see if they will stick. Quite possibly all of the theories have some merit. One of the great weaknesses of archaeology as a science is that like climatology it deals with a complex field, yet as humans archaeologists prefer simple explanations.

BTW, the Younger Dryas while technically part of the Pleistocene may well have delayed the onset of the Holocene. Study of plots of warming following the LGM show a steady trend punctuated by the YD. At the end of the YD the climate continues warming at very close to the same rates as before the YD.