Reading Earth's climate history through fossil pollens: an interview with Kim Yong-mi

Understanding future climate change often starts from researching Earth's past through fossils preserved in ancient sediments. By investigating the history of physical sciences, fossil scientists have researched ways to track long-term environmental change and generate the data needed to improve climate models. In this interview, Kim Yong-mi, a Senior Researcher at the Korea Institute of Geoscience, shared how microscopic fossils reveal Earth's climate history and how high-quality regional data can strengthen predictions of future climate change.

First, could you tell us about the research you’re currently working on?

I primarily study micropaleontology. When people think of fossils, they usually think of large ones like dinosaurs, but I specialize in micropaleontology—specifically, pollen fossils, where pollen grains are preserved just like dinosaurs. So, I’m conducting research to determine what kinds of plants thrived under what climate conditions in the past, how past climates changed based on those shifts, and, using that data, to predict what the climate will be like in the future.

This seems like a field of research I’ve never heard of before. How does your research contribute to climate modeling or help with future predictions?

For my pollen fossil research, I primarily use marine core sediments collected from the Ulleung Plateau in the East Sea. Geologic eras are divided into the Cenozoic, Mesozoic, and Paleozoic, right? Within the Cenozoic, I’ve primarily focused on studying the East Asian monsoon around the Korean Peninsula, breaking it down by geological epoch from the Miocene to the present. Additionally, these pollen fossils help me study not only climate change but also active faults on the southeastern continental shelf of the Korean Peninsula. By “active faults,” I mean the various fault lines found in Korea.

Faults that formed during very ancient geological eras may no longer be active, but faults that formed more recently—during the Quaternary period—can trigger earthquakes, such as the Gyeongju Fault, the Gyeongju Earthquake, and the Pohang Earthquake. Therefore, it’s important to determine when and where these faults are active. We were able to determine those time periods using our microfossil data, which is why I participated in that research. More recently, through microfossil studies of intertidal deposits in the Yeonggwang area of the West Sea, we’ve determined how much sea levels rose during specific periods in the past. By building models based on this data, we can generate and study baseline data to predict future sea-level rise and fall.

When conducting research on climate history through palynology, is there anything that surprised you the most, or any recent findings that left a deep impression on you?

Yes, among the research projects we’re currently working on, we’re also studying the subtropicalization of the Korean Peninsula. As you may have seen in the news, there are reports that apple cultivation areas are gradually shifting northward. It’s now being reported in the news that the Korean Peninsula is becoming increasingly subtropical and is truly bearing the brunt of climate change. However, when we look at the changes in pollen production during the geological periods we’re analyzing, this level of change is actually quite abrupt.

Seeing these rapid climate changes happening recently has really driven home to me just how essential climate research—specifically paleoclimate research—is. For accurate modeling in this area, such input data is absolutely crucial. We’re increasingly realizing that we need a large amount of very well-calibrated, high-resolution data. Also, while climate change is occurring globally, sudden and extreme weather events are appearing regionally, so we also need regional climate data.

You mentioned that regional data is important. Do you conduct joint research or collaborate with other research institutions in East Asia?

Yes, we are currently engaged in international collaboration with the Qingdao Institute of Marine Geology in China. We’re referring to the Yellow Sea, also known as the West Sea. We are located on the eastern side of the West Sea, while the Qingdao Institute of Marine Geology is on the western side. The acoustic records from that coastline vary not only by latitude but also significantly from region to region. So, we’re mapping paleoclimate events in the Yellow Sea and compiling all that climate data. Our overarching goal is to understand how these regional differences—which have historically existed throughout the Pan-Yellow Sea region—might change in the future, and we’re currently advancing our research with that in mind.

What do you think is the greatest benefit of conducting research through international collaboration?

First of all, while we in Korea have exceptional capabilities—and our researchers excel in both terrestrial and marine geology—China can provide equipment that we don’t have the means to analyze. Additionally, we can complement the capabilities we gain from China, and this mutual cooperation is the greatest benefit.

You just mentioned equipment—are there any new technologies or research methods you’re most looking forward to in future fossil pollen research?

Yes, in terms of technological advancements, what we’re looking forward to is this: currently, when studying fossil pollen, we actually identify it manually using a microscope. We determine, for example, that “this has certain characteristics, so it’s pine pollen,” or “that has different characteristics, so it’s oak pollen.” However, since pine and oak pollen each indicate different climate conditions, this identification is crucial. While it’s currently done manually, we’re now in the age of AI, so we’re attempting to develop programs that can automatically identify these microfossils by training AI models on their images and characteristics.

Looking ahead, as you mentioned, the climate crisis is becoming increasingly severe. Through this research on microfossils, is there a specific goal you hope to achieve regarding the climate crisis?

First and foremost, at a time when research on regional extreme weather events is becoming increasingly important, such regional data is absolutely essential for climate models to be accurate and sophisticated. Therefore, producing high-quality regional data is another goal of mine. Additionally, regarding carbon neutrality, we’re not only studying plant pollen but also investigating how carbon—including total carbon values found in sediments from carbon sources like combustion—is distributed across different strata and what potential these strata have as carbon sinks. So, I’m planning to conduct climate research using a multi-proxy approach, incorporating various different proxies not only in paleoclimatology but also in studies of past and future climate change.