Guest essay by Eric Worrall
A new study suggests people in Ancient Britain thrived despite major abrupt changes to their climate.
Confronted With Severe Climate Change, Ancient Britons Kept Calm and Carried On
Soon after the glaciers melted at the end of the last Ice Age, our planet was vulnerable to abrupt and dramatic shifts in climate, including prolonged cold snaps that lasted for decades. New research suggests early hunter-gatherers living in the British Isles didn’t just manage to survive these harsh conditions—they actually thrived.
Ancient hunter-gatherers living at the Star Carr site some 11,000 years ago in what is now North Yorkshire didn’t skip a beat as temperatures plunged around the globe in the immediate post-glacial era, according to new research published in Nature Ecology & Evolution. This latest research suggests abrupt climate change wasn’t catastrophically or culturally disruptive to this long-standing community, and that early humans were remarkably resilient and adaptable in the face of dramatic climate shifts.
The Star Carr population arrived in this part of the world at the very beginning of the Holocene Era, which happens to be the era we still find ourselves in. The Holocene started when the Ice Age came to end some 11,500 years ago, but in this transitionary period, the Earth’s climate was still subject to dramatic shifts. In this immediate post-Ice Age era, rising sea levels, changing ocean currents, and frigid ocean temperatures produced prolonged cold periods that rekindled memories of the prior frozen epoch. Average global temperatures dropped by as much as three degrees Celsius, creating cold snaps that lasted more than a hundred years. In parts of the British Isles, Eurasia, and North America, temperatures got so low that entire forests stopped growing. Anthropologists figured early humans living in northern Britain suffered during this time, but the new study suggests this wasn’t the case.
“It has been argued that abrupt climatic events may have caused a crash in Mesolithic populations in Northern Britain, but our study reveals that at least in the case of the pioneering colonizers at Star Carr, early communities were able to cope with extreme and persistent climate events,” lead author Simon Blockley, a researcher at Royal Holloway, University of London, said in a statement.
The abstract of the study;
The resilience of postglacial hunter-gatherers to abrupt climate change
Simon Blockley, Ian Candy, Ian Matthews, Pete Langdon, Cath Langdon, Adrian Palmer, Paul Lincoln, Ashley Abrook, Barry Taylor, Chantal Conneller, Alex Bayliss, Alison MacLeod, Laura Deeprose, Chris Darvill, Rebecca Kearney, Nancy Beavan, Richard Staff, Michael Bamforth, Maisie Taylor & Nicky Milner
Understanding the resilience of early societies to climate change is an essential part of exploring the environmental sensitivity of human populations. There is significant interest in the role of abrupt climate events as a driver of early Holocene human activity, but there are very few well-dated records directly compared with local climate archives. Here, we present evidence from the internationally important Mesolithic site of Star Carr showing occupation during the early Holocene, which is directly compared with a high-resolution palaeoclimate record from neighbouring lake beds. We show that—once established—there was intensive human activity at the site for several hundred years when the community was subject to multiple, severe, abrupt climate events that impacted air temperatures, the landscape and the ecosystem of the region. However, these results show that occupation and activity at the site persisted regardless of the environmental stresses experienced by this society. The Star Carr population displayed a high level of resilience to climate change, suggesting that postglacial populations were not necessarily held hostage to the flickering switch of climate change. Instead, we show that local, intrinsic changes in the wetland environment were more significant in determining human activity than the large-scale abrupt early Holocene climate events.
Read more (paywalled): https://www.nature.com/articles/s41559-018-0508-4
Some studies have suggested that events like the Younger Dryas, an abrupt thousand year return to ice age conditions with a temperature drop between 2C – 6C, might have struck with full force in just a few months.
Mini Ice Age Took Hold Of Europe In Just Months
Thu, 12 Nov 2009 11:29 UTC
Just months – that’s how long it took for Europe to be engulfed by an ice age. The scenario, which comes straight out of Hollywood blockbuster The Day After Tomorrow, was revealed by the most precise record of the climate from palaeohistory ever generated.
Around 12,800 years ago the northern hemisphere was hit by the Younger Dryas mini ice age, or “Big Freeze”. It was triggered by the slowdown of the Gulf Stream, led to the decline of the Clovis culture in North America, and lasted around 1300 years.
Carbon isotopes in each slice revealed how productive the lake was and oxygen isotopes gave a picture of temperature and rainfall. They show that at the start of the Big Freeze, temperatures plummeted and lake productivity stopped within months, or a year at most. “It would be like taking Ireland today and moving it up to Svalbard” in the Arctic, says Patterson, who presented the findings at the BOREAS conference in Rovaniemi, Finland, on 31 October.
“This is significantly shorter than what has been suggested before, but it is plausible,” says Derek Vance of the University of Bristol, UK. Hans Renssen, a climate researcher at Vrije University in Amsterdam, the Netherlands, says recent findings from Greenland ice cores indicate the Younger Dryas event may have happened in one to three years. Patterson’s results confirm this was a very sudden change, he says.
The only reasonable conclusion which can be drawn from this evidence in my view is that humans and ecosystems are able to cope with abrupt climate shifts on a scale which makes our current gradual warming trend look like a flat spot.