
Dr Philip Holden
Senior Lecturer In Earth System Science
School of Environment, Earth & Ecosystem Sciences
Biography
Professional biography
Phil completed his DPhil in computational modelling of X-ray lasers in 1991 from the University of York, after which he held research positions in the University of York, Université Paris-Sud and the Czech Institute of Physics. He then spent ten years in the finance sector, designing and modelling approximately $2 billion of asset financings in the transport sector. He returned to academia via an MSc in Quaternary Science from the University of London (RHUL/UCL) in 2006. He joined the Open University in 2007, initially as a post doctoral researcher on glacial-interglacial cycles. Phil's main focus is the development of computationally efficient Earth system models, with particular focus on interdisciplinary model coupling applications, integrated assessment and uncertainty quantification. He has authored 83 peer-reviewed papers (July 2024), including 15 in Nature and Science journals.
Research interests
Phone: +44 7095 351 332
Science Applications
● Energy transition modelling
● Interdisciplinary studies in ecology and anthropology
● Future and paleo climate-carbon cycle dynamics and uncertainties
● Bayesian calibrations of climate sensitivity, future sea-level rise and CO2 fertilisation
● Paleoclimate reconstruction from microfossil assemblages
● Contributed simulations for IPCC AR5 and AR6
Model development
● FRANTIC network: financial shock propagation through the global equity ownership network
● PLASIM-GENIE: Intermediate complexity Atmosphere-Ocean-Carbon-Cycle GCM
● PALEO-PGEM: Pliocene-Pleistocene climate emulator for coupling applications
● ENTSML: managed land use model
● PLASIM-ENTSem: future climate emulator for integrated assessment applications
● GENIEem: future carbon-cycle emulator for integrated assessment applications
● BUMPER: Bayesian paleoclimate reconstruction from microfossils
● MEMLM: Multi Ensemble Machine Learning Model (paleoclimate reconstruction from microfossils)
Methodological Development
● Emulating high-dimensional inputs and outputs
● Emulator-filtered ABC/history matching
Selected recent publications
Stranded fossil-fuel assets translate to major losses for investors in advanced economies, Semieniuk et al, Nature Climate Change (2022)
A stronger role for long-term moisture change than for CO2 in determining tropical woody vegetation change, Gosling et al, Science (2022)
Reframing incentives for climate policy action, Mercure et al, Nature Energy (2021)
Tectonic and climatic drivers of Asian monsoon evolution, Thomson et al, Nature Communications (2021)
Late Quaternary dynamics of Arctic biota from ancient environmental genomics, Wang et al, Nature (2021)
Past extinctions of Homo species coincided with increased vulnerability to climatic change, Raia et al, One Earth, 3, 480-490 (2020)
Potential for large-scale CO2 removal via enhanced rock weathering with croplands, Beerling et al, Nature (2020)
Revisiting Antarctic ice loss due to marine ice cliff instability, Edwards et al, Nature (2019)
Modeling the ecology and evolution of biodiversity: Biogeographical cradles, museums, and graves, Rangel et al, Science (2018)
Macroeconomic impact of stranded fossil fuel assets, Mercure et al, Nature Climate Change (2018)
Climate–carbon cycle uncertainties and the Paris Agreement, Holden et al, Nature Climate Change (2018)
Teaching interests
Current teaching
S831: Earth and Environmental Science Challenges (co-Chair, author "Climate change")
S319: Geology and Sustainability (Module team, author "Earth's climate system")
S397: Terrestrial Ecosystems (Module team, author "Interpedendence")
S350: Evaluating Contemporary Science (Module team, "Evaluating data in contemporary science")
Past teaching
S808: Earth Science: a Systems Approach (Chair)
S396: Ecosystems (Module team)
S250: Science in Context (Module team)
U216: Environment (Tutor marked assignments)
S279: Our Dynamic Planet (Tutor marked assignments)
Projects
CERES - Stage 1
Staff time for Phil Holden for a sub-contract with the University of Exeter.
Transition Risk Exeter Ltd Contract
The original pioneering NERC-funded project identified significant financial risks associated with the rapid shift to sustainable energy systems. These included the potential loss of value in fossil fuel assets and infrastructure which could lead to financial shocks and instability in the financial sector. TREX will extend this methodology to provide a robust characterisation and quantification of transition risks and opportunities for individual firms adjacent to the fossil fuel industry. Tailored methodologies will be used to derive a Transition Value at Risk, a dollar value corresponding to the likely transition-related revenue upside, or downside, for listed firms in the following industrial groupings: • Dependent suppliers to oil and gas e.g. oil and gas services, mining equipment. • Clients of oil and gas e.g. electricity utilities, producers of steel, cement, chemicals, fertilisers. • Producers of fossil-fuel consuming products e.g. transport and heating manufacturers. • Component suppliers to fossil-fuel technologies e.g. manufacturers of components of combustion engines, gas turbines, blast furnaces.
Financial risk and the impact of climate change
The Bank of England has recently drawn attention to the risks to the UK economy posed by the impacts of climate change and climate policy. The risks that extreme climatic events pose to assets and infrastructure have already been the subject of substantial research. However, the risks to financial assets of changes in the policy regime designed to achieve climate targets, notably risks surrounding the impacts of stranded fossil fuel assets (SFFA), have received much less attention. In this project, we propose to study the risk of SFFA shocks to the UK economy, its resilience to such shocks, and the policy options that could improve this resilience. Using in-depth knowledge and expertise on the financial sector, we will develop new tools to determine the risks that SFFA pose for financial stability. We will also further develop our stakeholder engagement methodology, through which we co-develop strategies to assess and understand risk propagation, and policy to minimise the risk of instability. Award value is £250,000 at 80%FEC
Plausible policy pathways to Paris
The Paris agreement commits nations to pursuing efforts to limit the global temperature rise to 1.5 degrees. This represents a level of transformation of the socio-economic and energy systems that substantially exceeds the scenarios that have been found using most conventional integrated assessment models (IAMs) based on equilibrium assumptions. Such strong mitigation also violates the pattern scaling assumptions used to derive environmental impacts in IAMs because of the rapid reversal in emissions growth. We will use a new, fully dynamic IAM that does not rely on equilibrium or pattern scaling assumptions to provide a set of more realistic dynamic pathways to reach the 1.5 degree target. The assessment will identify policy options and the degree of negative emissions required.
EoI NERC - Plausiable Pathways Policy Impact funding
The 1.5C programme will achieve a high level of policy impact through publication of results in the IPCC special report SR1.5. But this alone does not necessarily provide answers to the specific questions of UK policymakers. To achieve the programme's full impact potential for UK policy demands an in-depth dialogue between programme participants and stakeholders, together with detailed policy impact and effectiveness modelling to answer the specific questions arising from the dialogue in the light of an integrated view of the new results generated by the 1.5C programme.
Robust infrastructure decision-making for the wind industry
The project aim is to build a robust decision-making tool for future investment in new wind turbines, which takes account of climate change scenarios, and government policy scenarios in energy and climate change, as well as the business operations and profitability of the stakeholders. Research questions include: • How is wind power potential in the UK impacted by both uncertain future climate states and policy trajectories? • What strategies for investing in new wind farms would provide the foundation for a more robust strategy under climate change and/or diverse policy outcomes? • What vulnerabilities still remain, and how can they be reduced (e.g. through modelling studies, or monitoring external factors deemed relevant to the decision-making process)?
Bayesian User-friendly Multi-Proxy Environmental Reconstructions (resubmission)
BUMPER is an “embedded research” project, aimed towards strengthening interdisciplinary connections and funded by ReCoVER (Research on Changes of Variability and Environmental Risk). The project addresses transfer functions, widely used tools to infer past climate from microfossil assemblages preserved in lake and ocean sediments. In collaboration with ecologists at the Florida Institute of Technology and NIMBioS (National Institute for Mathematical and Biological Synthesis, University of Tennessee), BUMPER is developing a computationally-fast Bayesian transfer function to produce a user-friendly tool for paleoecologists. The principal motivation for developing a Bayesian approach is the calculation of reconstruction-specific uncertainty that, for instance, greatly increases the power of multi-proxy reconstructions.
Quantifying Uncertainty in ANTarctic Ice Sheet instability
Large parts of the Antarctic ice sheet lie on bedrock below sea level and may be vulnerable to a positive feedback known as Marine Ice Sheet Instability (MISI), a self-sustaining retreat of the grounding line triggered by oceanic or atmospheric changes. There is growing evidence MISI may be underway throughout the Amundsen Sea Embayment (ASE) of West Antarctica. If this is sustained the region could contribute up to 1-2 m to global mean sea level, and if triggered in other areas the potential contribution to sea level on centennial to millennial timescales could be two to three times greater. However, physically plausible projections of Antarctic MISI are challenging: numerical ice sheet models are either too low in spatial resolution to explicitly resolve grounding line processes or else too computationally expensive to assess modeling uncertainties. The proposed work brings together and analyses two new datasets that complement each other in model complexity – a large ensemble generated with a low resolution model, and a small ensemble from a high resolution model – by constructing a new emulator of the relationship between them.
Publications
Book Chapter
Journal Article
Transforming US agriculture for carbon removal with enhanced weathering (2025)
Potential pension fund losses should not deter high-income countries from bold climate action (2023)
Reply to: When did mammoths go extinct? (2022)
Substantial carbon drawdown potential from enhanced rock weathering in the United Kingdom (2022)
Climate pathways behind phytoplankton-induced atmospheric warming (2022)
Stranded fossil-fuel assets translate to major losses for investors in advanced economies (2022)
Reframing incentives for climate policy action (2021)
Tectonic and climatic drivers of Asian monsoon evolution (2021)
The role of habitat fragmentation in Pleistocene megafauna extinction in Eurasia (2021)
Late Quaternary dynamics of Arctic biota from ancient environmental genomics (2021)
A major change in rate of climate niche envelope evolution during hominid history (2020)
Past extinctions of Homo species coincided with increased vulnerability to climatic change (2020)
Potential for large-scale CO2 removal via enhanced rock weathering with croplands (2020)
An Introduction to Seshat: Global History Databank (2020)
System complexity and policy integration challenges: The Brazilian Energy- Water-Food Nexus (2019)
Multi-level emulation of complex climate model responses to boundary forcing data (2019)
Revisiting Antarctic ice loss due to marine ice cliff instability (2019)
PALEO-PGEM v1.0: a statistical emulator of Pliocene–Pleistocene climate (2019)
Climate–carbon cycle uncertainties and the Paris Agreement (2018)
Macroeconomic impact of stranded fossil fuel assets (2018)
Sensitivity of the Eocene climate to CO2 and orbital variability (2018)
BUMPER v1.0: a Bayesian user-friendly model for palaeo-environmental reconstruction (2017)
PLASIM–GENIE v1.0: a new intermediate complexity AOGCM (2016)
Building a traceable climate model hierarchy with multi-level emulators (2016)
Emulating global climate change impacts on crop yields (2015)
Worldwide impacts of climate change on energy for heating and cooling (2015)
Emulation and interpretation of high-dimensional climate model outputs (2015)
Historical and future learning about climate sensitivity (2014)
Long-term climate change commitment and reversibility: an EMIC intercomparison (2013)
Controls on the spatial distribution of oceanic δ13CDIC (2013)
A model-based constraint on CO2 fertilisation (2013)
The Mid-Brunhes Event and West Antarctic ice sheet stability (2011)
Precessional forcing of tropical vegetation carbon storage (2011)
Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials (2010)
A probabilistic calibration of climate sensitivity and terrestrial carbon change in GENIE-1 (2010)
A Bayesian palaeoenvironmental transfer function model for acidified lakes (2008)
Presentation / Conference
Embedding research into teaching: practices, motivations and impacts (2023)
Dynamic responses of Indian Summer Monsoon variability during past warm intervals (2022)