Cool Britannia : from Milankovich wobbles to ice ages

Abstract

The snow and intense cold of December 2010 – the coldest month since meteorological records began, is a timely reminder that despite living in a warm (‘interglacial’) period – the Holocene, climate in recent Earth History has been markedly colder for periods lasting many thousands of years. These ‘cold stages’ form part of the Quaternary geological period which spans the past 2.6 million years (Ma). It marks the transition from the sometimes ‘greenhouse’ climates of the Cretaceous and earlier Cenozoic, through to ‘Ice Age’ earth. We often hear that the Quaternary is synonymous with the ‘Ice Age’. In reality, this is somewhat misleading. Whilst there were numerous extended ‘cold periods’ or ‘glacials’ which did result in ‘Ice Ages’ during the Quaternary, equally, there were many ‘warm periods’ or ‘interglacials’ where the climate in Britain was at least as warm if not warmer than today. Quaternary ‘climate change’ has had a profound and lasting impact on our landscape. In particular, the form of much of the landscape is a legacy of our ‘Ice Age’ history. Understanding our ‘Ice Age’ history is important in understanding not just our landscape heritage and its conservation and sustainable use, but also in appreciating just how sensitive our land-mass is to the long-term forces of ‘climate change’. Within this paper, we explore the long-term history of ‘Ice Ages’ in Britain and Ireland, focussing on why they occurred, and when and how big they were