Climate researcher with new assignment

In order to unlock the secrets of the atmosphere, some climate researchers send balloons with measuring instruments miles up in the air. Gerald Haug, however, mainly goes in the other direction: into the depths. Drilling in sediments of seas and lakes is his profession. The analysis of so-called drill cores allows conclusions to be drawn about temperatures, precipitation levels and greenhouse gas concentrations of the last millennia to millions of years. Thanks to such historical reference points, climate data can be better classified in the here and now. Given Haug's specialization, it is no wonder that his job title seems exotic: he is a paleo-oceanographer. "The results of paleoclimate research play a central role in the investigation of the causes of climate change," says Haug. "They have led to a revolution in the understanding of our climate system."

Haug himself has made a major contribution to this revolution. For a long time, the cause of the great ice ages in the northern hemisphere 2.7 million years ago was unclear. According to palaeoclimatic data, it had been cold enough for 14 million years. What was missing was precipitation. Haug, together with other researchers, was able to prove that the ocean currents in the North Pacific changed significantly about 2.7 million years ago. As a result, the water surface temperature rose, which then led to more evaporation over the ocean and thus to more precipitation. Greenland and the north of America, Europe and Asia disappeared under a permanent ice cap. For this work Haug was honored in 2007 with the Gottfried-Wilhelm-Leibniz-Prize of the German Research Foundation, the most important research promotion prize in Germany.

Haug actually wanted to become an environmental geologist because he liked the strong practical relevance of this profession. However, after his studies and doctorate, he dedicated himself entirely to basic science, researching at leading institutes in Germany, Canada and the USA. In 2002 he finally habilitated at the Swiss Federal Institute of Technology Zurich (ETHZ). One year later, he took over the position of section head at the German Research Center for Geosciences in Potsdam and became a professor at the University of Potsdam. He returned to ETH Zurich in 2007, and in 2015 Haug returned to Germany and took on one of the four directorships at the Max Planck Institute for Chemistry in Mainz, continuing his teaching at ETH Zurich.

As head of the Department of Climate Geochemistry he was able to advance an unusual project in Mainz: the research sailboat Eugen Seibold. The Eugen Seibold is a deep-sea yacht for marine and climate research, designed for the contamination-free collection of seawater, plankton and air samples and their analysis in the laboratories on board. Haug was involved in the project from the conception to the christening in 2018: "Today, research vessels of up to 140 meters in length with crews of 30 to 80 men are mainly used for sample collection, which costs up to 100,000 euros a day. These ships are often oversized for the kind of sampling we need for climate research". Since the end of 2018, the Eugen Seibold has been sailing in the Atlantic Ocean, providing data that contribute to a better understanding of the complex processes of physics, chemistry and biology of the oceans and the atmosphere.

Haug himself is not involved in the current trips in the Atlantic Ocean. And there is also little time left for the hobby of sailing - Haug occasionally cruises with his own boat in the Greifswald Bodden. With the management of the oldest continuously existing scientific-medical academy of the world the next large challenge waited for him in this year. A member of the Leopoldina since 2012, Haug contributed to several publications of the National Academy on science-based policy advice and enjoyed the mediating role between science and politics. "As the National Academy of Sciences, the Leopoldina has great potential to actively and effectively support opinion formation in politics and society," said Haug at the end of 2019 on the occasion of his election as the Academy's 27th President. "The Leopoldina can contribute to the consensus on current issues and also future topics. This task is becoming increasingly important in our rapidly changing and increasingly complex world - nationally, European and worldwide," said Haug.

When the new president took office a few months later, the new coronavirus SARS-CoV-2 was spreading around the globe, especially from China. In six papers on SARS-CoV-2 and the pandemic triggered by the virus, the Academy developed options for action and thus provided a scientific foundation for the public discussion. Due to his new task, Haug's scientific work has been pushed into the background, but it does not completely leave him. For example, there are some gaps in our knowledge about the influence of the oceans on climate, which are a concern for the geologist. Specifically, the focus is on so-called nonlinear processes, i.e. the change between different climatic states. The classic example here is the El Niño and La Niña phenomena, which cause droughts and floods in tropical regions at irregular intervals.

Major climate changes have occurred repeatedly in the history of the earth. Gerald Haug can also read this from his drill cores. For example, his investigations of sediments off the coast of Venezuela revealed historical periods of drought, which correlated chronologically with the decline of the Mayan civilization in Central America. Haug also found evidence of the effects of climate change on history in other regions and eras, including a connection between weakened monsoon seasons and the fall of several Chinese dynasties. "These examples point to the sensitivity of highly developed cultures that exploit their environment to the limit," Haug said.

Today, this warning is more relevant than ever, because the natural dynamics of the climate are altered by human influence on a completely different scale. "With today's methods, we can see that, at the latest since the industrial revolution, a signal has been found in climate data that we can only explain with the influence of humans," says Haug. Due to the rapidly increasing concentration of greenhouse gases in the atmosphere, the earth will continue to warm up: "There is no doubt about it," the paleo-oceanographer states. Haug will continue to study climate change in detail and provide solutions - as a bridge-builder between science, politics and society.

National Academy of Sciences Leopoldina

The German Academy of Natural Scientists Leopoldina, founded in 1652, was appointed the National Academy of Sciences of Germany in 2008. In this capacity, it has two special tasks: representing German science abroad and advising politicians and the public on topics such as the coronavirus pandemic, biodiversity, climate change and the energy revolution.

Website of the Leopoldina