Tuesday, March 31, 2015

Climate Change Then and Now

Climate change in the past is more the rule than the exception. Earth and life have survived many changes in climate. Human civilization developed in a highly special period though - the last ten thousand years has been a period of exceptionally stable and (for humans) benign climate. Modern humans first emerged between 50,000 and 200,000 years ago, in the Pleistocene, a period of turbulent and frequently hostile climate. It's rapid and drastic climate changes may well have prevented our ancestors from developing agriculture. These climate changes have been far from benificent from the standpoint of existing species. Large scale reductions in territory and mass extinctions have been common. It's highly plausible that several of our brother species of humans met their ends in this way.

The most recent ten thousand years, the Holocene, hasn't been like that. Stability and very gradual change have been the rule.

Until the last 100 years. The rapid and unprecedented consumption of fossil fuels has provoked significant climate change that seems certain to continue and intensify. That change probably won't end civilization - at least not without a lot of further help from us - but it is sure to cause plenty of problems.