Source: Glacial archaeology – unlocking the climate time machine Author: Met Office Press Office Glacial archaeology is a new and emerging field made possible by the increasingly rapid melting of mountain ice due to climate change. Recent discoveries have left experts amazed. Dr Doug McNeall, co-host on the Met Office’s Mostly Climate podcast, chats with Dr Lars Pilø, a Norwegian glacial archaeologist, on how the disappearing ice is revealing secrets from the past. Climate projections indicate nearly half the world’s mountain glaciers could disappear by the end of this century, even if the world meets its most ambitious climate goals. The consequences of this are far reaching. The volume of ice on Earth has advanced and retreated over millennia. Yet the recent rate of melting of the cryosphere – the world of ice – has been far more rapid due to human influence. Ice has retreated on a time scale of decades rather than millennia, and this accelerated glacial shrinking over high ground has exposed ancient objects. Most of Lars Pilø’s work is in the mountains of Norway, where ancient ancestors hunted reindeer as they escaped the biting insects of the lowlands. He talks about the incredible sight when a relic, which was encased in ice, is found. Lars Pilø said: “It doesn’t look old: the ice acts as a time machine.” Some pieces date back 6000 years, when temperatures were higher in a period following the Holocene Thermal Optimum. Many of Lars’ discoveries also pinpoint a time when the mountain ice was far greater than now, when society across the northern reaches of Norway existed across an icy landscape. Lars describes finding many items lost over time, across ancient hunting sites and old ice-bound transport routes. From skeletons of dead animals to remnants of packhorse sleds. It’s a treasure trove of material culture now exposed as the glaciers recede. Interestingly he and his team still use packhorses to reach certain remote sites – an adept way of transporting specialist equipment and provisions for an extended survey. Glacial archaeology is also conducted across other icy realms in the Northern Hemisphere, from North America to the Alps: all regions experiencing similar challenges from mountain glacial melt. Bittersweet For researchers, the satisfaction of working in glacial archaeology is bittersweet. For all the excitement of discovering artefacts seemingly as fresh as the day they were lost, they know that their study is a race against time. In future the ice may not encase the land again, and in some places might be gone forever. Although not a linear decline, Lars confirms there is a continual glacial net loss and so it’s a matter of urgency to retrieve historic items that reveal more about how communities lived under different climatic environments. Dr Lars Pilø is the founder of the “Secrets of the Ice” website and twitter feed. Hear more about his work on the Mostly Climate podcast.