She is a geologist from the University of Zaragoza, a doctor from the University of Barcelona and a tenured scientist since 2014 at the Pyrenean Institute of Ecology, of the CSIC. Ana Moreno (Vilanova i la Geltrú, Barcelona, 1974) has delivered a conference this week, within the cycle of the University of Zaragoza “Researchers in search of the past”.
What do caves hide about climate change?
The caves, mainly in their stalagmites, hide information about how the climate has changed in the past. They tell us about periods that have been very hot or very cold or they tell us how rainfall has changed. This happens because they are connected with the climate: for a stalagmite to form there has to be dripping inside a cave and for there to be dripping, it has to rain in that area. So, through the type of rain, we can know what temperature was in that area or what different types of rain we could find. This helps us to relate what we see in the stalagmites with the climate that existed in the past. They are the paleoclimatic records of the past climate.
What are these paleoclimatic records for?
Paleoclimatology serves, above all, three objectives. On the one hand, to extend the record of climate change. Keep in mind that right now almost everything we analyze about climate change or current global warming is based on instrumental series of temperature and rainfall that, at most, are 100 or 150 years old. Paleoclimatology gives us temporal context, a vision into the past of what the climate was like. Second, it offers us the opportunity to better understand the causes, processes, and mechanisms of climate change. We have a book written about what the climate was like in the past, how it worked, what role the atmosphere could have, the ocean currents, even in moments of time when we have not had ice caps at the poles. It is as if we have different climate change scenarios, which allows us to better understand the system. This brings us to the third utility of past climate records, which is the possibility of improving predictive climate models, because we are getting data on how the climate works, that is, how the great laboratory that is has responded other times. the earth.
Is there still much to analyze in Aragon?
Yes, it would be overwhelming. In Aragon there are many caves. Only in the Pyrenees and in the Iberian System, we have large massifs of limestone rock, where caves develop. There are many, many caves and there are many records of stalagmites. Not all of them are interesting; if they are very old, millions of years old, we do not have the ability to study them in detail. Those do not help us to understand the weather. But there is still much work to be done in this field.
So what types of stalagmites are the ones that can give you the most valuable information?
Right now, people who are doing work in paleoclimatology are focusing on studying rapid climate change. In the past, we also have examples of periods when the climate changed rapidly; It is what interests us most, especially in relatively close periods of time. For example, in the last glacial cycles, at most the last 100,000 years, in which we have a system of ocean currents and the atmosphere that works similar to how it is today. In this time period, it is interesting to find rapid climate changes, which have occurred because a threshold has been crossed or because too much fresh water has been implanted in the Atlantic Ocean by melting the polar ice caps and that has changed the ocean currents … Phenomena of this type are the ones we are most interested in investigating in the past because, deep down, they are the ones most closely related to current climate change. We are interested in understanding well why they are produced and also how they spread throughout the planet and what reactions there are in different ecosystems.
Can this be done in Aragon?
Yes, we have already worked on quite a few abrupt climate changes in the past. For example, in the Pyrenees, we have worked in a period called recent Dryas, the Younger Dryas, which is a cold period that lasted 1,000 years and in which the entry and exit in that cold period occurred very quickly, in a few decades. This period has been recorded very well in some stalagmites, specifically, in the Seso cave, in Boltaña. In another cave, for example, in Teruel, in Ejulve, we have worked a lot on glacial termination, that is, we have been interested in seeing what the transition from a glacial period to an interglacial is like, which occurred 270 million years ago. It is also rapid climate change, for what it is on the geological scale: it occurred in a relatively short period of just 1,000 years. So we are interested in seeing how the entire climate system reorganizes itself.
What projects are you working on right now at the Pyrenean Institute of Ecology?
We are working on a project focused on the Pyrenees, in the westernmost area, approaching the central valleys of the Western Pyrenees and the Navarrese Pyrenees. It is an area that we have little investigated. We are trying to relate the information we obtain from sediment records, from the mud that we find at the bottom of the lakes and the information from caves. One of the focuses of this project is to relate the climate change that has occurred in the past and the impact it had on human societies. We are going to focus on the last 20,000 years. There are several opportunities to relate climate changes with anthropic changes and see aspects such as the beginning of agriculture, the migrations of some societies, the impact they could have on deforestation … We are going to work in different periods of time, but with that intention of relating climate to human impact.
This week, the International Day of Women and Girls in Science has been commemorated. What attracted you to dedicate yourself to paleoclimatology?
I was always very interested in all the topics that had to do with the environment, with pollution, with climate change … even before starting the Geology degree. I have always been quite sensitized in this regard. When I finished Geology and started my doctoral thesis, it was a time when all the issues related to paleoclimate, with the climate of the past, were beginning to be topical, because that was the moment when the IPCC reports began to come out, the Kyoto summits … Then, I saw that geology could also contribute a lot to that vision on climate change, by studying records from the past. I started working with marine sediments and now I am focusing on the more continental environment, with logs of lakes and caves. It is the idea of trying to relate the past to the present as much as possible to even provide data to improve future predictions.