We have some work ahead of us, but that’s normal: Studying the past to predict the future

Paleoscience deals with the past. But how can climate researchers combine data from millions of years of Earth’s history, when conditions varied greatly, to inform predictions of the future?

That’s the mammoth challenge now facing almost 50 leading paleoscientists and early-career researchers from around the world who attended “Lessons learnt from paleoscience on a possible 1.5-2°C warmer world in the future.” This workshop, held at the University of Bern, Switzerland, from 5 to 7 April, covered timescales from the Pliocene, or from roughly 5 million years ago, to the last few millennia.

It was the first meeting of Past Global Changes’ (PAGES) new Warmer Worlds Integrative Activity. This activity seeks to coordinate efforts of various PAGES working groups and to start preparations for a paleoscience contribution to a 2018 special report from the Intergovernmental Panel on Climate Change (IPCC) on the impacts of global warming of 1.5°C above pre-industrial levels. Some examples of previous papers from PAGES working groups related to predicting warmer times are here (PALeo constraints on SEA level rise 2, PALSEA2), here (PAGES 2k Network) and here (PAGES-PMIP Working Group on Quaternary Interglacials, QUIGS).

Huge spread of information

Hubertus Fischer (University of Bern), Alan Mix (Oregon State University, USA) and Katrin Meissner (University of New South Wales, Australia) organised the workshop, which consisted of individual presentations of current research plus collaborative efforts in smaller focus groups.

Fischer says bringing together participants who study a wide range of timescales was a brilliant way to start examining what paleoscience data can say about a rise in temperatures of 1.5°C.

“As a result of this meeting, we have a huge spread of information – from ice cores, to sea levels, to ocean processes, to ecosystems and more,” he says. “We can gain a very comprehensive picture of the Earth system, but to synthesise and draw conclusions is a demanding task. We will study the response of the Earth system in periods of the past that were warmer than present. Of particular interest in this respect is the Pliocene when atmospheric carbon dioxide concentrations were similar to today. In modern times, the human burning of fossil fuels has elevated concentrations to levels 40% higher than during preindustrial times.”

Meissner says the group was prepared for the challenges ahead – to see if paleoscientists can find periods in the past when climate conditions were analogous to what they are today and evaluate if major changes are likely to reoccur in the near future.

“We are changing CO2 concentrations at a very fast rate today,” she says. “While there is no perfect analogue in terms of the speed and the underlying cause of changes we see today, we can still learn a lot from the widespread expertise present at the meeting. For example, we can look at why and how did major changes in the climate system occur in the past? What do we know about the melting of continental ice sheets, changes in ocean circulation and the marine carbon cycle or changes in terrestrial carbon reservoirs, such as peat lands and permafrost?”

Paleoclimate research can help scientists to develop better predictions of what might happen in a warmer future. Fischer is optimistic: “There are certain impacts we will be able to predict – impacts that have direct implications for people living in different regions. For example, in Switzerland, the loss of glaciers will have a significant impact on water availability and, thus, agriculture and energy production. And this is likely to happen within the next 100 years.”

Paper writing in real-time

To get the IPCC contribution moving, workshop participants started to write the paper in Bern. This real-time writing approach, while the meeting was still in session, was a novel way to get the ball rolling, as opposed to waiting until everyone was back in their offices and battling other distractions.

Overall, Mix was happy with the workshop and the paper so far. “We know we have some work ahead of us, but that’s normal,” he says. “It was a fabulous team, with an incredible amount of talent in the room, and amazing and engaged young scientists. This Integrative Activity brought a lot of people together who wouldn’t usually directly interact.”

Unusual interactions provide inspiration

These unusual interactions were a highlight for many participants, including Willy Tinner, PAGES co-chair and Head of Paleoecology at the Institute of Plant Sciences at the University of Bern. The workshop had “shaken his knowledge,” he says.

“Normally at conferences you meet with people within a related field, and when you specialise you tend to only move in that field,” Tinner says. “On occasions like this, with all these brilliant people – who are producing some of the best work worldwide – it really pushes you forward, to think about and connect new things that you didn’t dare think about before.”

Qing Yan, associate professor at the Chinese Academy of Sciences, was excited by the scope of the presentations. “My expertise is global climate modeling, but now I have been able to learn about paleo records, the Last Interglacial and the Holocene,” says Yan, who studies changes in ice sheets and tropical cyclones. The Last Interglacial occurred 130,000 years ago, and the Holocene began about 10,000 years ago.

One of the highlights for Max Holloway, from British Antarctic Survey at Cambridge, UK, was hearing about current research, rather than just published papers, which can contain results that are months or years old. “In terms of the paper we’re working on for this workshop, we are focusing on what’s been published, but it’s good to know what the future perspectives are,” he says. “It’s refreshing to be here – you can get blinded sitting in your own office all day working on your own paper.”

Nerilie Abram, associate professor at the Australian National University whose work covers the last 2000 years, says gathering such a variety of research with a common goal was inspiring. “In the group, there is the feeling that we are developing something concrete – everything we have talked about is coming together, and we now have direction on how we can contribute,” she says.

Including a broad paleoscientific contribution is important for the scope of the IPCC report overall. “We’ll be writing for people who aren’t paleoscientists, for the IPCC report and beyond,” Mix says. “We’ll have a follow-up at PAGES’ 5th Open Science Meeting, which will take place in Spain this May, then try to submit the paper in June."

About PAGES

The PAGES project is a 25-year-strong international effort to coordinate and promote past global change research, to improve our understanding of past changes in the Earth system in order to improve projections of future climate and environment. The majority of PAGES outputs are written by paleoscientists who are active in more than 20 different PAGES working groups. PAGES is funded by the U.S. National Science Foundation and the Swiss Academy of Sciences, and supported in kind by the University of Bern. Read more on the PAGES website.