Major project looks for clues to future climate in the ocean floor

A consortium of international researchers have just initiated a geological time machine and turned back the clock several million years. Information on the prehistoric climate can teach us a lot about what might await us in as the climate is changing now and in the future. The consortium, aptly named Past to Future: towards fully paleo-informed future climate projections, has received a 15-million-euro Horizon grant  and will spend the next four years building more accurate climate models that can couple the past to the future.

"Paleo data (climate data from the extended past) are not yet fully integrated into existing climate models," says Anna von der Heydt, Associate Professor of physical oceanography and project coordinator from Utrecht University in the Netherlands.

"Typically, climate model scenarios are constructed using observational data, with paleo data added only afterwards. Our goal is to develop a method that incorporates paleo data directly into the model development from the start. This approach will ultimately lead to a more accurate picture of future climate changes."

Studying historical climate patterns can thus provide valuable insights into the mechanisms driving climate changes, helping us to refine our predictions and prepare for potential climatic shifts in the future.

GEUS analyses unique sediment cores

GEUS is one of the 24 project partners of the consortium with Prof. Paul Knutz leading a subproject aimed at understanding how ice sheets have varied and interacted with oceans over the last five million years. The GEUS team that besides Paul Knutz, consists of Senior researchers Kasia K. Sliwinska, and Lara Perez, and a postdoctoral researcher will study sediment cores from the northwest Greenland margin. The sediment cores (see example below) were collected during the 2023 Integrated Ocean Discovery Program (IODP) expedition 400 to gain novel insights into a deep past that has not been studied in this part of the Arctic before.

“Based on the ocean sediments, we will investigate the response of the Greenland Ice Sheet to climate states that are warmer than present”, says Prof. Knutz.

Photo: Sediment cores collected during the IOPD Expedition 400 in 2023 being inspected by two of GEUS reserachers Heike Zimmerman (left) and Lara Perez (right) (Photo: Paul Knutz, GEUS)

In collaboration with researchers at Niels Bohr Institute at the University of Copenhagen, the team will also generate a climate data set from the ice cores records in a new, more precise time scale (days to decades).

“Besides these activities, we will be involved in compiling and standardizing existing paleo data, as well as improving our understanding of the variability of the temperature and circulation of the ocean,” he adds.

All these data will be crucial for improving the climate model predictions.

Natural archives

What is it then, that the researchers look for in their paleoclimate archives? It can be tiny air bubbles trapped in ancient Antarctic and Arctic ice sheets, or fossilized plankton preserved in ocean sediments serve as natural climate archives. By examining their chemical composition, researchers can reconstruct all kinds of information about the climate conditions, such as temperature and greenhouse gasses concentration in the atmosphere at the time they were alive.

A key research goal of the GEUS team is to use sediments delivered by icebergs to reconstruct past transitions from cold glacial climate to warm and ice-free regimes in the ocean water masses west of Greenland.

Project leader Von der Heydt finds it remarkable that experts from so many different scientific disciplines are coming together for this project.

"This kind of collaboration doesn’t happen automatically, but it’s incredibly valuable," she claims. "We have to learn to speak each other’s language, which leads to fascinating discussions."

Lucas Lourens, Professor of Paleoclimatology at Utrecht University and co-project coordinator, emphasizes the urgency of this research and the insights it will bring.

"We are increasingly witnessing the effects of climate change, and while we already understand a great deal about the climate system, the speed at which these changes are occurring still raises many questions. For that reason, we particularly focus on identifying feedback mechanisms: complex processes triggered by climate change that, in turn, accelerate it further. By understanding how these mechanisms operate over long timescales, we better understand short term changes, too," says Lourens.

Read the scientific summary of the project on the European Commission website.