Benjamin Keenan, Biogeochemist

Photo showing Benjamin in the foreground with a volcano erupting the background
Benjamin during an eruption of Volcán de Fuego or Chi Q’aq’ in Guatemala

Hello everyone. I am a biogeochemist who uses ancient molecules found in lake sediments to investigate interactions between humans and their environment. I am finishing a PhD in biogeochemistry at McGill in Montréal, Québec. I like skiing and ice skating, jazz, and when the earth is not frozen over I spend my lot of time bike-camping and swimming outdoors. I moved to Canada after a degree in geological sciences in England/California and working as an environmental consultant, a water engineer, and as a research assistant at the Complutense University of Madrid.

My current research looks at how the lowland Maya interacted with their environment and how they responded to climate change over 3,300 years. I take samples from Central America, extract organic molecules known as lipids and analyse them using different methods. I use plant waxes as a proxy for vegetation and hydrological change (how wet or dry it was) in the past, polycyclic aromatic carbons (from the incomplete combustion of carbon) as a proxy for biomass burning the past, and faecal stanols as proxies for population change.

My first chapter shows that population declines in the southwest Maya lowlands are associated not only with drought at multiple times throughout history, but also with anomalously wet periods, and has also highlighted potential efforts to reduce soil erosion as well as the use of night soil (human waste) as fertiliser in the past. This work attracted a lot of media interest, including from the CBC, Haaretz, El Mundo, and Archaeology Magazine, and will be vulgarised in the magazine Le Climatoscope. It also forms part of the chapter “Climate Change and Variability in the Protoclassic” in Remaking Maya Civilization, Social and Political Transformations in the Protoclassic Maya Lowlands.

Benjamin wearing a striped shirt, shorts and wellington boots in a tree over a cliff reaching out to collect leaves for analyses
Benjamin in the field in Guatemala collecting leaves for plant wax analyses

Now I am in the process of writing my thesis, which I will submit in December, and working with a digital artist to create a virtual Itzan, the archaeological site where the samples I have analysed were taken from. I think it is important for people to know that ancient societies were affected by climate change and by looking at responses to environmental change in the past how we might better understand anthropogenic climate change today and in the future. I am particularly interested in migration as climate change adaptation and am a member of the McGill Refugee Research Group.

Most students are fortunate enough to be on campuses with interesting seminars and public lectures in different departments that you can attend and make connections between your interests, your research and what is happening in different areas and at different scales. This is interesting and can be fruitful, and helps prevent you from getting stuck in the rut of your niche bit of research. Attending talks in anthropology, geography, and social sciences has given me new perspectives for my thesis, where the question I am researching requires an interdisciplinary approach.

Figure from Keenan et al. (2021) showing population change in the context of palaeoclimate and changes in pollen (a proxy for deforestation).