At www.livescience.com/46312-popigai-crater-linked-eocene-mass-extinction.html …. this is one of those events normally attributed to climate change rather than catastrophism – mainly because joining up the dots between dating and geological chronology is riven with assumptions and elusions of accuracy. Climate did change towards the end of the Eocene – but is that a consequence rather than a cause?
New dating techniques now suggest a huge impact may have been responsible, and the Popigai crater in Siberia is being targeted as the strike point. This is where the Russians have found huge reserves of diamonds. This occurred around 33 million years ago and the evidence of a sudden and dramatic cooling are said to be the result of an 'impact winter' – a term not used of late. Clube and Napier gave their second book the title, 'The Cosmic Winter' saying that the Taurid meteor stream caused a series of such coolings through the Holocene and Late Pleistocene periods. Reading the above PR blurb it is amazing that geologists really think they can date precisely when events such as Popigai occurred (rather than in a broader sense). For instance, with a completely straight face the cosmic event that caused the extinction of the dinosaurs is said to have coincided in time with extinctions by just 33,000 years – according to the most precise dating techniques available. Perhaps they aren't precise enough if it took 33,000 years from impact to extinction.
The Eocene extinctions coincided with a sudden drop in temperatures, a spike that was fairly short lived prior to a return to warm temperatures – and the emergence of new species. The big question might be – to what extent did cosmic debris affect global temperatures during such recent events as the Little Ice Age?