Past Climate

Can isotopes help define the Anthropocene?

By Dr Jonathan Dean, Prof Melanie Leng and Prof Anson Mackay   The Anthropocene is a term that is increasingly being used to refer to the current interval in geological time in which humans have become a dominant force of global environmental change. It was coined by Prof Eugene Stoermer, a biologist, in the 1980s and popularised in the early 2000s by Prof Paul Crutzen, an atmospheric chemist. It is now indisputable that humans are leaving their mark on the planet (see the recent Climatica summary of the ‘Climate change: evidence and causes’ report here: http://climatica.org.uk/royal-society-national-academy-sciences-climate-change-evidence-causes). For instance, over the last century or so, atmospheric...

Quaternary science in the UK: 50 years of past climate research

2014 is a big year for Quaternary science! In January, the UK Quaternary Research Association (QRA) celebrated its 50th anniversary at the Royal Geographical Society in London. The QRA is a research organisation which focuses on the Quaternary Period – the last 2.6 million years of Earth’s history, which is broadly synonymous with ‘The Ice Age’. Quaternary science (the study of all things Quaternary) encompasses a wide range of research fields including: oceanography, glaciology, ecology, and human evolution. These strands of Quaternary research come together to build a detailed picture of the long-term changes in the Earth’s environment. Every year the QRA hosts an Annual...

Antarctic expedition to estimate thinning ice sheets

Antarctica might seem like a desolate and inhabitable continent with little to offer other than perhaps the sight of penguins, but it holds the answers to many scientific questions. Simply put, Antarctica is covered by kilometers-thick ice, frozen water which will melt when sufficiently warmed. Sea level around the world is therefore dependent on how fast Antarctica’s ice sheets melt. My research looks at past changes of ice sheet thickness. As a glacier melts and thins, rocks on its flanks become exposed to the atmosphere (specifically cosmic radiation). A technique called surface-exposure-dating is used to estimate when rocks became exposed at the glacier surface, creating...