CLIMET
CLIMET is an NWO ENW-XL funded consortium comprised of researchers from the Netherlands Institute of Ecology (NIOO-KNAW), Utrecht University, and Radboud University.
Our team of microbiologists, ecologists, and paleogeologists will map the impact of organic carbon and lanthanides on the Arctic methane cycle, from the genes involved in microbial metabolism to the impact on methane emissions from Greenland’s lakes.
The issues
Warming in the Arctic is progressing at nearly four times the global mean rate, raising the potential for positive feedbacks through increased greenhouse gas emissions. Methane is a far more potent greenhouse gas than carbon dioxide and most methane globally is produced by microbes in lakes and wetlands. The relative activity of micro-organisms that produce methane (methanogens) and those that consume it (methanotrophs) is therefore critical in determining how much methane is emitted from aquatic ecosystems, yet these processes are often treated as a “black box” in climate models. Because microbial community interactions are complex and studies of Arctic microbiomes are sparse, there is a significant knowledge gap that impedes predictions of (changing) methane emissions, especially in Arctic regions where lake densities are high. The challenge is urgent and escalating because Arctic lakes are changing quickly due to the effects of warming and we currently do not know whether such changes will cause a problematic positive feedback loop where there is a net increase in methanogens and methane production, or whether methane production will be mitigated by stimulating methanotrophs.
CLIMET research questions
- Is the supply and availability of dissolved organic matter and/or dust driving the methane cycle in Arctic lakes?
- Is the lanthanide cycle a missing link in our understanding of Arctic lake methane cycling?
- How do the ongoing changes in Arctic landscapes associated with climate warming influence positive or negative feedbacks on lake methane production?
Kangerlussuaq living laboratory
the area around Kangerlussuaq in South-west Greenland is an ideal living laboratory for lake CH4 studies. There are thousands of lakes in the area located adjacent, but hydrologically unconnected, to a major glacio-fluvial outwash plain which is a source of wind-borne dust. Dust deposition across this region has increased significantly in recent decades correlated with Greenland Ice Sheet discharge and there was a 20-year declining trend in lakewater dissolved organic carbon (DOC) concentrations (Saros et al 2019), which abruptly reversed in 2023 associated with a protracted rainfall anomaly (Saros et al 2025).
The research questions in CLIMET range in scale from molecular (genes, enzymes, metabolites) up to ecosystem scale, and consider lakes as part of an inter-connected landscape with variable fluxes of materials between land, atmosphere and water. The work plan therefore employs work packages (WP) that use methodologies and approaches from across microbiology (WPs 2, 3), microbial ecology (WPs 3, 4), lake ecosystem ecology and limnology (WPs 1, 4), earth and palaeo-sciences (WPs 1, 5).
Work package 1: Landscape-scale relationships among lake CH4 and environmental drivers
Aim: assessing the biogeochemical conditions across the Kangerlussuaq lake district and identifying key relationships with CH4 (cycling).
Work package 2: Key microorganisms and microbial metabolisms
Aim: characterizing lake microbial communities across the Kangerlussuaq lake district, identifying key microorganisms associated with CH4 cycling, and studying their microbial metabolic biodiversity.
Work package 3: Microbial community mechanisms and interactions
Aim: elucidating mechanisms underlying pelagic microbial CH4 consumption under varying dust/REE and DOM combinations
Work package 4: Field-scale mechanisms and interactions
Aim: determining how REE-dust-DOM treatments influence lake food webs and CH4 cycling at the ecosystem scale.
Work package 5: Long-term dynamics of lake DOM, dust and CH4 cycling
Aim: investigating long-term patterns and relationships between dust elements, DOM and microbial communities
Meet the CLIMET team
Prof. dr. Suzanne McGowan
Project lead, work package 1 lead
Head of Aquatic Ecology at the Netherlands Institute of Ecology (NIOO-KNAW) with >30 years of experience in palaeolimnology and aquatic ecology. Suzanne McGowan has worked in West Greenland since 1999. She spent 16 years at the University of Nottingham where she retains an Honorary Professorship, moved to the NIOO-KNAW in 2021, and was appointed as Special Professor in Aquatic Ecosystem Dynamics at the University of Utrecht in 2024. Projects in Greenland have been funded by a Marie Curie Research Fellowship, UKRI-NERC and EU-INTERACT with the central theme of investigating the impacts of environmental change on Arctic lakes. McGowan is an Honorary Fellow of the Freshwater Biological Association, Associate Fellow of the British Geological Survey and Treasurer of the International Paleolimnology Association. Her work spans biology, geology, geography and ecology in the UK, Denmark, Canada, Malaysia and the Netherlands and she brings a broad experience of leadership, collaboration and team-building.
Dr. Robert Jansen
Work package 2 lead
Robert Jansen has 15 years of experience in analytical (bio)chemistry and metabolomics. He combines untargeted metabolomics with other omics and classical biochemistry to link metabolites to enzymes, genes and organisms. He discovered several new metabolites in humans and microbes, and elucidated the function of a variety of uncharacterized enzymes. Currently, his group focuses on non-model microorganisms of environmental and medical importance in projects that are supported by ENW-XS (2021), ENW-M1 (2023) and RVO (2023). For this proposal, Robert brings essential expertise to characterize the metabolomes of environmental lake samples and isolated microbes, along with the enzymes they encode.
Dr. Paul Bodelier
Work package 3 lead
Paul Bodelier has more than 25 years of experience in microbiology, microbial ecology and biogeochemistry with a strong focus on functional ecology of microbes involved in elemental cycles (C, N, P, Fe, S). In this field he published, many key-findings in the field of methane microbiology, among which the discovery of novel phyla of methane degrading microbes, novel insights in biotic and abiotic control of methane emissions for various ecosystems like rice paddies, lakes, sediments, peat soils as agricultural soils. Bodelier supervised 10 PhD students as co-promoter, 6 post-docs as well as 4 research technicians. He has led two ESF programmes on methane cycling and acquired funding from a range of sources EFRO, NWO-TTW, NWO-open, NWO-TTW perspectief, NWA and BE-Basic. Bodelier has or served as editor on various editorial boards and recently, he became acting expert member of the ecological Authority in the Netherlands
Dr. Annelies Veraart
Work package 4 lead
Annelies Veraart is an experienced ecologist working on climate feedbacks and eutrophication effects in aquatic ecosystems. Her group uses field studies, lake-mesocosm experiments, laboratory incubations and meta-analysis to study drivers of methane and nitrous oxide cycling in ecosystems ranging from high Arctic wetlands to (sub-)tropical lakes. She is PI and co-PI in several multi-stakeholder projects (Aquafarm, NWO-DIGS; adviser in EU-MARIX and DFF-DrivNOS), and currently (co)-supervisor of 7 PhD students and 2 postdoctoral researchers. Her recent research has shown the important role of nutrients, trace metals and warming, as drivers of greenhouse gas transformations. In the proposed project, her expertise will bridge microbial, biogeochemical and ecological insights and place these in an ecosystem framework.
Prof. dr. Friederike Wagner-Cremer
Work package 5 lead
Rike Wagner-Cremer has ~30‐years’ experience in paleoecology, palaeoclimatology and plant physiology, on modern to glacial-interglacial and beyond timescales in arctic to sub-tropical environments.Key interests are paleoproxy development and application on the interface between geology and biology with a focus on natural and human induced climate change and the role of vegetation. Experience from sub-tropical to northern sub-arctic vegetation zones where her research is centred on the high north incl. Greenland since 2010. She is (co-)PI in several national and international projects and (co-)supervised ~20 PhDs at UU and international. She has led and participated in field campaigns, of which more than 10 to the high North and three to Greenland. As Paleoecology chairholder she manages a group of 10 employees and as head of department Physical Geography she is responsible for ~140 fte scientific and non-scientific employees.
