Programme details

The Pole-Ocean-Pole project, also referred to as POP, is interested in the North and South poles and oceans, in particular the Atlantic Ocean.
Comparisons of rapid climate changes recorded in the marine sediment with those in the ice cores provide better understanding of why and how the climate varied in a recent geological past. Four countries participate in POP: Switzerland, France, Great Britain and Spain.

Objective of POP Research

The objective of the POP project and what we are doing in my laboratory here, is to reconstruct the details of what happened in the past. We know this mainly from records from the polar ice cores, but we know it also from cores of sediments from the bottom of the ocean, particularly in the North Atlantic.

The Sediment Samples

The sediment is a veritable record of the past. Under the POP project, samples are taken from ocean floor by the ship Marion-Dufresne.

Analysis of Sediment Samples

We use many different techniques for estimating past changes in the temperature of the water. We measure stable isotope ratios, stable isotopes of oxygen. We look at the micro-fossils in the cores and count the abundance of different species, some of which like warm water and some like cold water. And we make other geochemical measurements to estimate temperature.

Ice Cores

The POP project is not based only on sediment but also on ice.
The analysis of the ice cores gives a very accurate determination of changes that took place in the composition of the atmosphere which have a direct influence on the climate.

Comparison of Records

By comparing the records from marine and ice cores, the POP project has thus been able to reconstitute some rather surprising phenomena.
The ice samples taken in Greenland show, indeed, that the atmospheric temperature changed very quickly. This is due to the fact that the warm water that carries heat to this region stopped at a certain time. This cooling had direct repercussions on the surface temperature in the Atlantic, that fluctuates in a way similar to Greenland. Conversely, the temperature of the ocean floor varies more like the atmospheric temperature over Antarctica.

Interpretation

The only way to test climate predictions for the future, is to look in the past, where this has happened in the past.
So there is a link between analysis of past climate and predictions for the future.

Conclusion

Records of past climate, although they do not reproduce what future conditions will be, teach us that the climatic system is capable of producing upsets in the global circulation of the oceans, or sharp variations in temperature, in a lapse of time of a single human generation.