Day By Day

Thursday, January 14, 2010

For the past couple of decades climate change has been a fad, almost an obsession, across a wide range of scientific disciplines. Almost everything imaginable has been related in some way to climate change or to human impact on the environment. People in the science biz understand this sort of phenomenon -- fads come and go and hopefully when the tide of enthusiasm for the new idea recedes it leave behind some useful information of lasting value.

It seems that the enthusiasm for environmental explanations in prehistory is beginning to abate. Numerous publications in the recent past have attributed all sorts of things -- migrations, the rise and fall of cultures, technological innovations, etc. to climate change. One of the biggest of these was the beginnings of agriculture. The narrative went something like this. As the ice sheets retreated at the end of the last Ice Age [about 12,000-10,000 ago] the climate in many parts of Eurasia became warmer and drier. In some of those regions hunter-gatherers who had exploited a wide variety of resources over a broad geographic range began to concentrate on a limited number of these, adopted a more sedentary way of life, and began to develop the social and technological innovations associated with the "neolithic revolution". Now, however, scientists are beginning to question the idea that climate change precipitated social and technological change. In fact they are now arguing just the opposite, that the innovations associated with the origins of agriculture depended on a stable climate regime.
Sustainable farming and the introduction of new crops relies on a relatively stable climate, not dramatic conditions attributable to climate change. Basing their argument on evolutionary, ecological, genetic and agronomic considerations, Dr. Shahal Abbo, from the Levi Eshkol School of Agriculture at the Hebrew University of Jerusalem, Israel, and colleagues, demonstrate why climate change is not the likely cause of plant domestication in the Near East. Rather, the variety of crops in the Near East was chosen to function within the normal east Mediterranean rainfall pattern, in which good rainy years create enough surplus to sustain farming communities during drought years. In the authors' view, climate change is unlikely to induce major cultural changes.
Read the whole thing here.

This is the way real science operates in the absence of political pressures. Ideas emerge and spread widely, are tested in a variety of contexts, and then are either abandoned or modified.