Helen Habicht, Molecular Paleoclimatologist

Adriane

I am a molecular paleoclimatologist, meaning I examine organic molecules (biomarkers) preserved in the geologic record to study past climate and environmental change. Biomarkers are compounds which can be traced to a single organism, class of organisms, or environmental process. They are useful tools for reconstructing climate, environment, and ecosystem changes because they record conditions at the time of their deposition, and can be preserved in sediments for millions of years.

My research is focused on discovering how the climate and environment in the Arctic has changed in the past. Due to anthropogenic (human-induced) climate change, the Arctic is currently undergoing rapid and unprecedented change. Paleoclimate records help us understand the natural variability of the climate system. They provide perspective on the extent and rapidity of current change, and can help predict how climate may change in the future.

A ‘Tree of Life’ illustrating the three domains of life and some biomarkers characteristic of the major groups of organisms. Many of these compounds can be preserved in sediments and rocks. Molecular paleoclimatologists study how the presence, absence, or variations in chemistry of these compounds relates to environmental controls such as temperature or primary productivity. Figure adapted from Briggs and Summons (2014).
Lake sediments contain organic compounds from terrestrial  (land) and aquatic sources such as higher land plants, microbes living in surrounding soils or the lake sediments themselves, and various kinds of algae and microorganisms that live in the water column. Using biomarkers, it is possible to examine contributions to sedimentary organic matter from the three domains of life, bacteria, archaea and eukarya as in the figure on the right, thus providing accurate paleoenvironmental information. As lake sediments accumulate, the oldest material will be at the bottom and the youngest material at the top. By analyzing samples from a sediment core, we observe how climate and environment at the lake change through time. Figure adapted from Castañeda and Schouten (2011).

My study site is Lake El’gygytgyn (Lake E), a meteorite impact crater formed 3.6 million years ago, located in northeast Russia ~100 km north of the Arctic Circle. I generate my data by extracting the organic material from samples from a sediment core from the bottom of the lake. I measure abundances and distributions of the biomarkers preserved in the sediments to reconstruct climatic and ecosystem changes over the last one million years. This period of Earth’s history is part of the Pleistocene, an epoch dominated by strong alternations between cold glacial periods and warm interglacial periods (see the ‘CO2: Past, Present, Future‘ page for a discussion on glacial and interglacial periods). By examining the biomarkers at Lake E, I can determine changes in variables such as temperature and precipitation associated with these climatic cycles. I can also use the biomarkers to identify what plants lived around the lake, and what sorts of primary producers (algae) were present in the lake. This information on past environmental variability is valuable as the climate continues to change rapidly.

I love being a scientist because I get to learn something new every day! There are always new questions to be asked and answers to be found either in my own research or the scientific literature. I enjoy working with colleagues and students to generate datasets that provide new insight about Earth’s climate. I also love that my job provides me with many opportunities to travel and meet new people!

For anyone who wants to be a scientists, know that being a graduate student is often incredibly challenging. There is so much to learn, so much research to be done, and numerous demands on your time. I think it is essential to develop a strong support network. This can include family, friends, your cohort, colleagues, and mentors. These people will help encourage and inspire you if you get discouraged or distressed by the trials of scientific research. They will remind you why you began a career in science in the first place—your love of learning!

Follow Helen on her personal Twitter here and/or on the UMass Biogeochemistry Twitter here to learn more about her research!

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