I am an environmental geoscientist, educator and entrepreneur based in Aotearoa New Zealand. My work runs from the chemistry of cave minerals, which hold a record of past rainfall, to the carbon and acidity changes now reshaping the country's largest river.
Caves · Climate · Ecosystems · Environment
As Principal Investigator on the MBIE Endeavour Fund programme Emerging Climatic Pressures, run with Lincoln Agritech Ltd, I lead work on the effects of climate change in freshwater ecosystems. The programme looks at how the cycling of carbon between land, water and atmosphere changes the acidity and biogeochemistry of water. As atmospheric carbon and temperatures rise, freshwater systems are trending more acidic (higher carbon dioxide) and are losing their breath (lower oxygen). What this means for future water quality and water security is being investigated by an interdisciplinary team using real-time sensing, experimentation, numerical modelling, and kaupapa Māori (indigenous sociological) research.
My scientific roots trace to subterranean caves and aquifers. I began by using geochemical methods to understand the structure and function of sub-surface food webs (stygofauna), then progressed to reading the geological record of climate change encoded in cave carbonate deposits (speleothems) with greater fidelity. That work produced kinetic proxies based on the decay of organic metal complexes, which return past infiltration in volumetric units rather than as a relative index, and which have revealed megadroughts that conventional isotope records miss.
Alongside the New Zealand caves, I have worked on raised coral atolls in the South Pacific, where the rainfall is governed by El Niño Southern Oscillation and the islands sit in the cyclone belt. Tropical island karst continues to be a focus of my work, with records in development spanning the Holocene, through last glacial period and beyond.
More recently I have taken a leading collaborative role in characterising the impact of massive carbonate biomineralisation by invasive gold clams on the Waikato River, a critical waterway in Aotearoa New Zealand. This is an Emerging Climatic Pressures collaboration with Earth Sciences New Zealand.
At a high level, my programme of research sits within aquatic and carbonate geochemistry, and addresses the processes intermediated by organic and mineral nanoparticles as well as other types of reactive surface, including soils, pyrolysed organic matter and mineral surface complexes. Examples include the modification of nutrient availability to phytoplankton as carbon dioxide changes (MBIE, Emerging Climatic Pressures), the retention of nitrate by pyrolysed organic matter (biochar) in edge-of-field denitrifying bioreactors (MBIE), and the transfer of a signal between a cave drip and the crystal it forms (Rutherford Discovery, Marsden).
Recent work includes a reconstruction of Miocene Arctic climate from Greenland speleothems, published in Nature Geoscience, and a Nature Communications study showing that warming drives dissolved organic carbon out of pristine alpine soils.
Since 2021: 1,329 citations · h-index 20 · i10-index 39
Google Scholar, updated August 2026
First use of the kinetic proxy in a high-resolution Chinese speleothem, showing megadroughts that δ¹⁸O and prior calcite precipitation proxies do not record. Uncertainty is propagated across nine sources, giving past infiltration in volumetric units.
A review of nanoparticles and organic matter as intermediaries at the boundary between dissolved and particulate phases, where they carry trace elements, compete for them, and set the rate at which they are exchanged.
My interest in what happens below the surface began with an undergraduate project on groundwater food webs under the Canterbury Plains. Since then the work has taken me through caves across global cave and karst systems, and alluvial aquifers in Australia, and the rivers and lakes of Aotearoa New Zealand. After a decade as an academic at the University of Waikato, I joined Lincoln Agritech Ltd: a R&D company owned by Lincoln University (NZ), where I lead the Emerging Climatic Pressures MBIE Endeavour programme.
Science Leader, Emerging Climatic Pressures programme (LVLX2302). Adjunct Associate Professor at University of Waikato and Lincoln University. Founder and Managing Director, Waikato Scientific Ltd.
Five-year research fellowship (Royal Society of New Zealand, $800K). Promoted to Associate Professor in 2020. Founded the Waikato Environmental Geochemistry group.
Ten years establishing and running a research group. EU MSCA RISE PI (QUEST programme, linking Cambridge, JGU Mainz, PIK Potsdam). Marsden Fund panel member (Earth Sciences & Astronomy, 2022–2024).
National Centre for Groundwater Research and Training. Iron nanoparticle–arsenic interactions during surface water-groundwater exchange.
NERC Doctoral Scholarship. Colloidal geochemistry of speleothem-forming groundwaters. Supervisor: Prof. Ian Fairchild.
Most Distinguished Student award.
Published in
Moseley GE, Koltai G, Baker JL, … Hartland A et al. (2025) Nature Geoscience 18: 1252–1258.
A reconstruction of Arctic climate in the late Miocene from speleothems in North Greenland, recording warm intervals and terrestrial climate variability in mineral archives preserved for millions of years.
Full list: Google Scholar · ORCID 0000-0002-1864-5144
First use of the kinetic proxy in a high-resolution Chinese speleothem, showing megadroughts that δ¹⁸O and prior calcite precipitation proxies do not record. Past infiltration is reported in volumetric units, with uncertainty propagated across nine sources.
Pearson AR, Fox BRS, Hellstrom JC, ... Hartland A (2024) Warming drives dissolved organic carbon export from pristine alpine soils. Nature Communications 15: 3488.
Giesche A, Hodell DA, Petrie CA, ... Hartland A, ... Breitenbach SFM (2023) Recurring summer and winter droughts from 4.2–3.97 ka in north India. Comms Earth & Environment 4: 138.
Höpker SN, Breitenbach SFM, Grainger M, Stirling CH, Hartland A (2024) Characterising the decay of organic metal complexes in speleothem-forming cave waters. Geochimica et Cosmochimica Acta 373: 98-108.
Lindeman I, Hansen M, Scholz D, Breitenbach SFM, Hartland A. (2022) Effects of organic matter complexation on partitioning of transition metals into calcite: cave-analogue crystal growth experiments. Geochimica et Cosmochimica Acta 317: 118-137.
Nava-Fernandez C, Hartland A, Gázquez F, et al. (2020) Pacific climate reflected in Waipuna Cave drip water hydrochemistry. HESS 24: 3361–3380.
Blyth AJ, Hartland A, Baker A (2016) Organic proxies in speleothems: new developments, advantages and limitations. Quaternary Science Reviews 149: 1–17.
Hartland A, Larsen JR, Andersen MS, Baalousha M, O'Carroll D (2015) Association of arsenic and phosphorus with iron nanoparticles between streams and aquifers: implications for arsenic mobility. Environmental Science & Technology 49: 14101–14109.
Mohammadi A, Corbett T, French A, Lehto NJ, Hadfield J, Jarman P, Sandwell D, Shokri A, Schipper L, Hartland A (2022) Application of diffusive gradients in thin films for monitoring groundwater quality. ACS ES&T Water 2: 518–526.
The SYP began as a problem in a cave. Sampling dripwater through a season means either living underground or leaving something behind that can do it for you, and the early prototypes went into Waipuna Cave and then to Niue, where one was dragged off by a crab and recovered in pieces, still logging. Waikato Scientific exists to turn that into equipment other people can rely on: automatic sensing and sampling technology for remote environmental deployments. The company markets, sells and supports the SYP Mark III Automatic Fluid Sampler, which collects up to 58 discrete, silicon-sealed samples over year-long deployments on a rechargeable battery and is used by researchers worldwide, including at Vanderbilt, Cornell College, Rouen and Northumbria. Open-source research software is at github.com/waikatosci.
Commissioned for the Royal Society's 150th anniversary feature Past & Future. On what caves can record beyond climate: earthquakes, volcanic eruptions, soil carbon loss, and the New Zealand lineage of cave science running back to Chris Hendy. Read the article
Television coverage of the cave monitoring programme and what stalagmite chemistry can say about New Zealand's rainfall future. Watch
Findings from the Emerging Climatic Pressures programme led by Lincoln Agritech, alongside operational perspectives from Lutra and Watercare on what these changes mean for source water monitoring, treatment process design and risk planning. Watch the webinar
On the environmental pressures reshaping New Zealand's longest river: geothermal carbon dioxide, invasive gold clams, and the difficulty of responding to several of them at once. Read the article
How Corbicula fluminea strips around 14 tonnes of calcium carbonate from the Waikato River each day, disrupting water treatment chemistry and mobilising arsenic into forms that conventional treatment may not remove. Read the article
Interview on the biosecurity implications of Corbicula fluminea for freshwater infrastructure, hydroelectric operations, and indigenous species. Listen
On using cave mineral archives to reconstruct New Zealand's climate history, and what stalagmite chemistry says about past rainfall variability. Listen
On the use of speleothem records to understand how New Zealand's rainfall extremes may intensify under climate change. Read the article
Interview on elevated CO₂ concentrations in the Waitomo Glowworm Cave and implications for cave conservation. Listen
Feature on the EU-funded QUEST programme and the development of novel speleothem proxies linking cave chemistry to past climate. Read the article
Photo essay on the QUEST research network's fieldwork across New Zealand cave systems. Read the article
On the Rutherford Discovery Fellowship programme to develop quantitative speleothem proxies of past rainfall in New Zealand. Read the article
I am based at the Ruakura Research Estate in Hamilton, New Zealand. For research enquiries, collaboration proposals or postgraduate supervision:
adam.hartland@lincolnagritech.co.nz
Lincoln Agritech profile
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