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Inflection point of human history 

discovered in paleoclimate

Professor Jungjae Park, 

Department of Geography





In the past, the lives of all creatures on the Earth were determined by the climate. Only the living creatures that adapted to the climate change could survive, and the climate exerted a great influence on the birth of humankind and the development of civilization. Professor Jungjae Park is an unrivaled researcher in the area of paleoclimate and paleoenvironment. He interprets the history of civilization from the perspective of climate by recovering the footprints made on the Korean Peninsula and examining the climate at the time. Today, with frequent climate disasters caused by global warming, the view of consilience encompassing astronomy, geology, biology, and anthropology suggests multidimensional views and insights to overcome the climate crisis era.



1.

What is the reason behind the lack of paleoclimate research in Korea?

Paleoclimate research is the study of climate over long periods of time, including the geological age, and it uses samples preserved in their natural state. For example, when you date and analyze the stalagmite, glacier, growth ring, coral reef, and lake sediments of limestone caves, you can identify the changes in vegetation, precipitation, or temperature. However, in places like Korea with a long history of human habitation and a small landmass, it is really difficult to secure samples. Even if you are lucky enough to obtain the samples, the stored information shows that the environment was disturbed by humans, thereby making it difficult to gather the climate data you are looking for. 



2.

Please explain to us your paleoclimate research methods.

I was previously unable to find adequate samples, but since 2011, when I was assigned to Seoul National University, I have been collecting and studying the cores and sediments from Oreum on Jeju Island. It is thanks to Jeju Island having a smaller population than other places and Oreum not having been influenced by humans due to its isolated location. The sediments in Oreum include carbonate, silt, clay, and organic matter. If we do the preconditioning processing with hydrochloric acid, hydrofluoric acid, and sulfuric acid, only the pollen with hard shells remains. When we put these on the slides and observe them with a microscope, we can observe different shapes of pollen depending on the species and discover which plant was largely distributed depending on the number. We can generally identify 300–400 pollen samples per slide, and it is a tedious process where we need to categorize the pollen patterns one by one and count the number of each. Since a large amount of data is required for accurate analysis, it takes quite a long time.



3.

What are the ecological characteristics of the ancient Korean Peninsula?

After analyzing the sediments of Oreum on Jeju Island, we were able to discover the pollen of oaks, not the pine trees that we often see today. Before the start of agriculture, over 60 percent of the land of the ancient Korean Peninsula was covered with oak trees. However, when people cleared forests for rice farming around 3,000 years ago, pines, which are resistant to disturbances, began to grow. While oak trees grow slowly but become taller than pine trees in a stable environment, pine trees shrink if they do not get sunlight. Had the natural climate of the Korean Peninsula been left undisturbed, there would be more oak trees, but it changed because of humans. Besides, alder trees, which prefer damp areas, used to grow naturally near the rivers. However, as people made the areas along the rivers and streams into farmland, the number of trees decreased significantly. 






4.

What is the difference between today’s climate crisis and the climate change of the past?

Since the birth of the Earth, climate change has always been taking place. During the Medieval Warm Period around 900–1,200, which is relatively recent, the temperature rose and the glaciers disappeared with the increased surface temperature of the North Atlantic Ocean. However, during the Little Ice Age from 1400 to the end of the 19th century, the average temperature of most areas in the northern hemisphere dropped. France’s Mer de Glace expanded, and the great flood occurred, which led to the reduction in the crop yield, causing famine and contagion. However, such problems occurred when the temperature dropped. There has never been an issue of temperature rise such as now. The speed of temperature rise and its rate are both high. Last year, the global average temperature increased by up to 1.1℃ compared to the pre-industrial period. The World Meteorological Organization (WOM) also announced that the chance of a 1.5℃ rise in the next five years is close to 50 percent. 



They are collecting sediment cores in Mulyeongari Oreum Seogwipo, Jeju Island 


5.

Are there past precedents we need to pay attention to in order to prepare for the climate crisis?

In the late 17th century, during the Little Ice Age, the Korean Peninsula also experienced the Kyungshin Famine and the Eulbyeong Great Famine. Poor harvests and harmful insects reduced the crop yield dramatically, and strong typhoons as well as contagion led to the death of more than one million people. Since it had not been long after the end of the Japanese invasion of Korea in 1592 and the Qing invasion of Joseon, it was harder to respond. However, during the same period, the Qing dynasty developed greatly. Emperor Kangxi, considered one of the wisest kings, listened to the expostulations of his servants and exempted those in areas greatly damaged by drought from paying taxes, even subsidizing the cost of houses for people who had lost their homes due to wildfire. Cases of climate crisis such as the one we are facing now cannot be found in history. However, unlike the climate change of the past, global warming can be overcome sufficiently with the determination of humankind. We need to continue our efforts of reducing carbon emissions in the long run and prepare institutions and systems to be ready for disasters caused by climate change. In addition, if we can predict climate change more accurately thanks to the development of science and technology, I believe we can overcome the climate crisis.



6.

How did you come to study paleoclimate, which is an unfamiliar research area in Korea?

I had a huge interest in biogeography, so I went to the University of California, Berkely to study after completing my master’s. As my supervising professor’s interests switched to paleoclimate, I also naturally came to study it. During my doctorate, I analyzed lake sediments in Mexico, and the process of matching the research results to the historical hypothesis was very interesting. For example, the Teotihuacán civilization of Mexico, despite its glory, dramatically declined in 600–700 A.D., and one of the reasons was climate change. We were able to demonstrate it through research, and the process was like reading a mystery novel. There hasn’t been much research on paleoclimate, and I think it offers more room to use one’s imagination to connect the historic incidents and climate change.



Pine pollen(left) and oak pollen(right) 



7.

Please leave a comment for students facing various societal problems including the climate crisis.

The societal issues we will face going forward will become more complicated. Moreover, the climate crisis cannot be addressed with science alone, as it is an issue involving many areas, such as economics, society, culture, and politics. When humanities scholars, natural scientists, social scientists, and engineers all gather to address the issue, we need someone who can manage and supervise all areas. I hope students engage in interdisciplinary studies rather than focusing on only one area. Also, I believe you can be acknowledged if you enjoy your work. Instead of letting your parents’ or society’s expectations determine your future, I hope you find what you are really interested in with all your passion through various experiences during your undergraduate years.