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  2. Dr Philip Bernard Holden

Dr Philip Bernard Holden

Profile summary

Research interests

Phone: +44 7095 351 332

My research centres upon the evaluation of Earth system uncertainty through the development and application of computationally fast models, both process-based and statistical, addressing past, present and future climate. I performed a suit of ~50 climate-carbon cycle ensemble experiments with GENIE for contribution to Working Group I of the IPCC Fifth Assessment Report (AR5).

My work uses GENIE (an intermediate complexity carbon-cycle model with a moderately complex representation of the physics and biology of the ocean) and PLASIM (a substantially more complex model of the atmosphere for use in climate projections). I have recently completed coupling these two models to create PLASIM-GENIE, a fully 3D intermediate complexity AOGCM, opening up a range of possible future applications. I am also interested in paleoclimate reconstruction from biological proxies and have developed and applied a computationally-fast user-friendly Bayesian transfer function BUMPER.

Recent published research includes:

Development of an emulator of the future climate change projections of PLASIM. An emulator is a statistical description of a model that produces a fast approximation to the model’s output, enabling applications that would not be possible with the model itself. Ongoing work has coupled this emulator to impact models to evaluate climate change impacts on crops, human health, energy demands for heating and cooling, and hydro-electric power potential.

Design of a model of land use change (a representation of land used for agriculture) that I have incorporated into GENIE. I applied the resulting model to derive a probabilistic quantification of the terrestrial carbon cycle response to fossil fuel emissions and also to build an emulator of the global carbon cycle. This emulator will provide a substantial upgrade for the carbon-cycle component of integrated assessment models, models that quantify fossil fuel emissions but lack a detailed description of what happens to the CO2 and how long it stays in the atmosphere.

Design of a large ensemble of coupled climate-carbon cycle configurations of GENIE that I have applied to investigate the uncertainty in oceanic uptake of CO2 and its isotopes. Work is ongoing to apply this ensemble to transient glacial-interglacial carbon cycle simulations.

A probabilistic calibration of the uncertainty of the simulated future Earth system response (climate, vegetation, ocean circulation and sea ice) to changes in atmospheric CO2, using ensembles of GENIE simulations constrained by Last Glacial Maximum climate.

GENIE ensembles of simulations of glacial climate to address i) the role of de-glacial melt-water forcing and, potentially, WAIS retreat in explaining the behaviour of Antarctic climate observed in the EPICA ice-core record and ii) the role of orbital changes in the glacial-interglacial variability of tropical vegetation. An on-going project is applying these simulations, together with emulations of PLASIM, to address the evolution of species diversity in South America over the last million years.


Research groups

NameTypeParent Unit
Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)CentreFaculty of Science


Externally funded projects

Plausible policy pathways to Paris
RoleStart dateEnd dateFunding source
Co-investigator31 Oct 201631 Jul 2018NERC NERC (Natural Environment Research Council)

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.

Bayesian User-friendly Multi-Proxy Environmental Reconstructions (resubmission)
RoleStart dateEnd dateFunding source
Lead01 Jan 201631 Dec 2016University of Exeter

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
RoleStart dateEnd dateFunding source
Co-investigator01 Aug 201531 Jan 2016University of Exeter

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.


Potential for large-scale CO2 removal via enhanced rock weathering with croplands (2020-07-09)
Beerling, David J.; Kantzas, Euripides P.; Lomas, Mark R.; Wade, Peter; Eufrasio, Rafael M.; Renforth, Phil; Sarkar, Binoy; Andrews, M. Grace; James, Rachael H.; Pearce, Christopher R.; Mercure, Jean-Francois; Pollitt, Hector; Holden, Philip B.; Edwards, Neil R.; Khanna, Madhu; Koh, Lenny; Quegan, Shaun; Pidgeon, Nick F.; Janssens, Ivan A.; Hansen, James and Banwart, Steven A.
Nature, 583 (pp. 242-248)

Spatial probabilistic calibration of a high-resolution Amundsen Sea Embayment ice sheet model with satellite altimeter data (2020-05-05)
Wernecke, Andreas; Edwards, Tamsin; Holden, Philip; Nias, Isabel and Edwards, Neil
The Cryosphere, 14(5) (pp. 1459-1474)

Is there warming in the pipeline? A multi-model analysis of the Zero Emissions Commitment from CO2 (2020)
MacDougall, Andrew H.; Frölicher, Thomas L.; Jones, Chris D.; Rogel, Joeri; Matthews, H. Damon; Zickfeld, Kirsten; Arora, Vivek K.; Barrett, Noah J.; Brovkin, Victor; Burger, Friedrich A.; Eby, Michael; Eliseev, Alexey V.; Hajima, Tomohiro; Holden, Philip B.; Jeltsch-Thömmes, Aurich; Koven, Charles; Mengis, Nadine; Menviel, Laurie; Michou, Martine; Mokhov, Igor I.; Oka, Akira; Schwinger, Jörg; Séférian, Roland; Shaffer, Gary; Sokolov, Andrei; Tachiir, Kaoru; Tjiputra, Jerry; Wiltshire, Andrew and Ziehn, Tilo
Biogeosciences, 17 (pp. 2987-3016)

Quantitative genetics of body size evolution on islands: an individual-based simulation approach (2019-10-10)
Diniz-Filho, JAF; Jardim, L; Rangel, TF; Holden, Philip; Edwards, Neil; Hortal, J; Santos, AMC and Raia, P
Biology Letters, 15(10)

Sensitivity of atmospheric CO2 to regional variability in particulate organic matter remineralization depths (2019-07-31)
Wilson, Jamie; Barker, Stephen; Edwards, Neil; Holden, Philip and Ridgwell, Andy
Biogeosciences, 16(14) (pp. 2923-2936)

Coupled climate–carbon cycle simulation of the Last Glacial Maximum atmospheric CO2 decrease using a large ensemble of modern plausible parameter sets (2019-06-18)
Kemppinen, Krista M. S.; Holden, Philip B.; Edwards, Neil R.; Ridgwell, Andy and Friend, Andrew D.
Climate of the Past, 15 (pp. 1039-1062)

System complexity and policy integration challenges: The Brazilian Energy- Water-Food Nexus (2019-05)
Mercure, J-F.; Paim, M. A.; Bocquillon, P.; Lindner, S.; Salas, P.; Martinelli, P.; Berchin, I. I.; de Andrade Guerra, J. B. S. O.; Derani, C.; de Albuquerque Junior, C. L.; Ribeiro, J. M. P.; Knobloch, F.; Pollitt, H.; Edwards, N. R.; Holden, P. B.; Foley, A.; Schaphoff, S.; Faraco, R. A. and Vinuales, J. E.
Renewable and Sustainable Energy Reviews, 105 (pp. 230-243)

Multi-level emulation of complex climate model responses to boundary forcing data (2019-02)
Tran, Giang T.; Oliver, Kevin I. C.; Holden, Philip B.; Edwards, Neil R.; Sóbester, András and Challenor, Peter
Climate Dynamics, 52(3-4) (pp. 1505-1531)

Producing Policy-relevant Science by Enhancing Robustness and Model Integration for the Assessment of Global Environmental Change (2019-01)
Warren, R. F.; Edwards, N. R.; Babonneau, F.; Bacon, P. M.; Dietrich, J. P.; Ford, R. W.; Garthwaite, P.; Gerten, D.; Goswami, S.; Haurie, A.; Hiscock, K.; Holden, P. B.; Hyde, M.R.; Joshi, S. R.; Kanudia, A.; Labriet, M.; Leimbach, M.; Oyebamiji, O. K.; Osborn, T.; Pizzileo, B.; Popp, A.; Price, J.; Riley, G.; Schaphoff, S.; Slavin, P.; Vielle, M. and Wallace, C.
Environmental Modelling & Software, 111 (pp. 248-258)

Revisiting Antarctic ice loss due to marine ice cliff instability (2019)
Edwards, Tamsin L.; Brandon, Mark A.; Durand, Gael; Edwards, Neil R.; Golledge, Nicholas R.; Holden, Philip; Payne, Antony J.; Ritz, Catherine and Wernecke, Andreas
Nature, 566 (pp. 58-64)

Crop Productivity Estimates for Past Societies in the World Sample-30 of Seshat: Global History Databank (2019)
Turchin, P.; Currie, T.; Levine, J.; Oyebamiji, O.; Edwards, N.; Holden, P.; Hoyer, D.; Feeney, K. and Whitehouse, H.
The Holocene

PALEO-PGEM v1.0: a statistical emulator of Pliocene–Pleistocene climate (2019)
Holden, Philip B.; Edwards, Neil R.; Rangel, Thiago F.; Pereira, Elisa B.; Tran, Giang T. and Wllkinson, Richard D.
Geoscientific Model Development, 12(12) (pp. 5137-5155)

Modeling the ecology and evolution of biodiversity: Biogeographical cradles, museums, and graves (2018-07-20)
Rangel, Thiago F.; Edwards, Neil R.; Holden, Philip B.; Diniz-Filho, José Alexandre F.; Gosling, William D.; Coelho, Marco Túlio P.; Cassemiro, Fernanda A. S. and Colwell, Robert K.
Science, 361, Article eaar5452(6399)

Macroeconomic impact of stranded fossil fuel assets (2018-07)
Mercure, J.-F.; Pollitt, H.; Viñuales, J. E.; Edwards, N. R.; Holden, P. B.; Chewpreecha, U.; Salas, P.; Sognnaess, I.; Lam, A. and Knobloch, F.
Nature Climate Change, 8 (pp. 588-593)

Climate–carbon cycle uncertainties and the Paris Agreement (2018-07)
Holden, P. B.; Edwards, N. R.; Ridgwell, A.; Wilkinson, R. D.; Fraedrich, K.; Lunkeit, F.; Pollitt, H. E.; Mercure, J. -F.; Salas, P.; Lam, A.; Knobloch, F.; Chewpreecha, U. and Viñuales, J. E.
Nature Climate Change, 8 (pp. 609-613)

Environmental impact assessment for climate change policy with the simulation-based integrated assessment model E3ME-FTT-GENIE (2018-04)
Mercure, Jean-Francois; Pollitt, Hector; Edwards, Neil R.; Holden, Philip B.; Chewpreecha, Unnada; Salas, Pablo; Lam, Aileen; Knobloch, Florian and Vinuales, Jorge E.
Energy Strategy Reviews, 20 (pp. 195-208)

Sensitivity of the Eocene climate to CO2 and orbital variability (2018-02-23)
Keery, John S.; Holden, Philip B. and Edwards, Neil R.
Climate of the Past, 14 (pp. 215-238)

BUMPER v1.0: a Bayesian user-friendly model for palaeo-environmental reconstruction (2017-02-01)
Holden, Philip B.; Birks, H. John B.; Brooks, Steven J.; Bush, Mark B.; Hwang, Grace M.; Matthews-Bird, Frazer; Valencia, Bryan G. and van Woesik, Robert
Geoscientific Model Development, 10(1) (pp. 483-498)

Physical and economic consequences of sea-level rise: a coupled GIS and CGE analysis under uncertainties (2016-12)
Joshi, Santosh R.; Vielle, Marc; Babonneau, F; Edwards, Neil R. and Holden, Philip B.
Environmental and Resource Economics, 65(4) (pp. 813-839)

PLASIM–GENIE v1.0: a new intermediate complexity AOGCM (2016-09-21)
Holden, Philip B.; Edwards, Neil R.; Fraedrich, Klaus; Kirk, Edilbert; Lunkeit, Frank and Zhu, Xiuhua
Geoscientific Model Development, 9 (pp. 3347-3361)

Inferring late-Holocene climate in the Ecuadorian Andes using a chironomid-based temperature inference model (2016-06-01)
Matthews-Bird, Frazer; Brooks, Stephen J.; Holden, Philip B.; Montoya, Encarni and Gosling, William D.
Climate of the Past, 12 (pp. 1263-1280)

Building a traceable climate model hierarchy with multi-level emulators (2016-04-18)
Tran, Giang T.; Oliver, Kevin I. C.; Sóbester, András; Toal, David J. J.; Holden, Philip B.; Marsh, Robert; Challenor, Peter and Edwards, Neil R.
Advances in Statistical Climatology, Meteorology and Oceanography, 2(1) (pp. 17-37)

Climate model emulation in an integrated assessment framework: a case study for mitigation policies in the electricity sector (2016-02-15)
Foley, A. M.; Holden, P. B.; Edwards, N. R.; Mercure, J-F.; Salas, P.; Pollitt, H. and Chewpreecha, U.
Earth System Dynamics, 7(1) (pp. 119-132)

Emulating global climate change impacts on crop yields (2015-12-01)
Oyebamiji, Oluwole K.; Edwards, Neil R.; Holden, Philip B.; Garthwaite, Paul H.; Schaphoff, Sibyll and Gerten, Dieter
Statistical Modelling, 15(6) (pp. 499-525)

Worldwide impacts of climate change on energy for heating and cooling (2015-10)
Labriet, Maryse; Joshi, Santosh R.; Vielle, Marc; Holden, Philip B.; Edwards, Neil R.; Kanudia, Amit; Loulou, Richard and Babonneau, Frédéric
Mitigation and Adaptation Strategies for Global Change, 20(7) (pp. 1111-1136)

Agricultural productivity in past societies: toward an empirically informed model for testing cultural evolutionary hypotheses (2015-07)
Currie, Thomas E.; Bogaard, Amy; Cesaretti, Rudolf; Edwards, Neil R.; Francois, Pieter; Holden, Philip B.; Hoyer, Daniel; Korotayev, Andrey; Manning, Joe; Garcia, Juan Carlos Moreno; Oyebamiji, Oluwole K.; Petrie, Cameron; Turchin, Peter; Whitehouse, Harvey and Williams, Alice
Cliodynamics, 6(1) (pp. 24-56)

Emulation and interpretation of high-dimensional climate model outputs (2015)
Holden, Philip B.; Edwards, Neil R.; Garthwaite, Paul H. and Wilkinson, Richard D.
Journal of Applied Statistics, 42(9) (pp. 2038-2055)

The dynamics of technology diffusion and the impacts of climate policy instruments in the decarbonisation of the global electricity sector (2014-10-31)
Mercure, J. F.; Pollitt, H.; Chepreecha, U.; Salas, P.; Foley, A. M.; Holden, P. B. and Edwards, N. R.
Energy Policy, 73 (pp. 686-700)

Historical and future learning about climate sensitivity (2014-04-16)
Urban, Nathan M.; Holden, Philip B.; Edwards, Neil R.; Sriver, Ryan L. and Keller, Klaus
Geophysical Research Letters, 41(7) (pp. 2543-2552)

PLASIM-ENTSem v1.0: a spatio-temporal emulator of future climate change for impacts assessment (2014-02-26)
Holden, P. B.; Edwards, N. R,; Garthwaite, P. H.; Fraedrich, K.; Lunkeit, F.; Kirk, E.; Labriet, M.; Kanudia, A. and Babonneau, F.
Geoscientific Model Development, 7 (pp. 433-451)

Long-term climate change commitment and reversibility: an EMIC intercomparison (2013-08)
Zickfeld, Kirsten; Eby, Michael; Alexander, Kaitlin; Weaver, Andrew J.; Crespin, Elisabeth; Fichefet, Thierry; Goosse, Hugues; Philippon-Berthier, Gwenaëlle; Edwards, Neil R.; Holden, Philip B.; Eliseev, Alexey V.; Mokhov, Igor I.; Feulner, Georg; Kienert, Hendrik; Perrette, Mahé; Schneider von Deimling, Thomas; Forest, Chris E.; Friedlingstein, Pierre; Joos, Fortunat; Spahni, Renato; Steinacher, Marco; Kawamiya, Michio; Tachiiri, Kaoru; Kicklighter, David; Monier, Erwan; Schlosser, Adam; Sokolov, Andrei; Matsumoto, Katsumi; Tokos, Kathy S.; Olsen, Steffen M.; Pedersen, Jens O. P.; Ridgwell, Andy; Shaffer, Gary; Yoshimori, Masakazu; Zeng, Ning and Zhao, Fang
Journal of Climate, 26(6) (pp. 5782-5809)

Historical and idealized climate model experiments: an intercomparison of Earth system models of intermediate complexity (2013-05-15)
Eby, M.; Weaver, A. J.; Alexander, K.; Zickfeld, K.; Abe-Ouchi, A.; Cimatoribus, A. A.; Crespin, E.; Drijfhout, S. S.; Edwards, N. R.; Eliseev, A. V.; Feulner, G.; Fichefet, T.; Forest, C. E.; Goosse, H.; Holden, P. B.; Joos, F.; Kawamiya, M.; Kicklighter, D.; Kienert, H.; Matsumoto, K.; Mokhov, I. I.; Monier, E.; Olsen, S. M.; Pedersen, J. O. P.; Perrette, M.; Philippon-Berthier, G.; Ridgwell, A.; Schlosser, A.; Schneider von Deimling, T.; Shaffer, G.; Smith, R. S.; Spahni, R.; Sokolov, A. P.; Steinacher, M.; Tachiiri, K.; Tokos, K.; Yoshimori, M.; Zeng, N. and Zhao, F.
Climate of the Past, 9 (pp. 1111-1140)

Controls on the spatial distribution of oceanic δ13CDIC (2013-03-19)
Holden, P. B.; Edwards, N. R.; Müller, S. A.; Oliver, K. I. C.; Death, R. M. and Ridgwell, A.
Biogeosciences, 10(3) (pp. 1815-1833)

Carbon dioxide and climate impulse response functions for the computation of greenhouse gas metrics: a multi-model analysis (2013-03-08)
Joos, F.; Roth, R.; Fuglestvedt, J. S.; Peters, G. P.; Enting, I. G.; von Bloh, W.; Brovkin, V.; Burke, E. J.; Eby, M.; Edwards, N. R.; Friedrich, T.; Fröhlicher, T. L.; Halloran, P. R.; Holden, P. B.; Jones, C.; Kleinen, T.; Mackenzie, F. T.; Matsumoto, K.; Meinshausen, M.; Plattner, G.-K.; Reisinger, A.; Segschneider, J.; Shaffer, G.; Steinacher, M.; Strassmann, K.; Tanaka, K.; Timmermann, A. and Weaver, A. J.
Atmospheric Chemistry and Physics, 13(5) (pp. 2793-2825)

A model-based constraint on CO2 fertilisation (2013-01-23)
Holden, P. B.; Edwards, N. R.; Gerten, D. and Schaphoff, S.
Biogeosciences, 10(1) (pp. 339-355)

Precessional forcing of tropical vegetation carbon storage (2011-07)
Gosling, William D. and Holden, Philip B.
Journal of Quaternary Science, 26(5) (pp. 463-467)

The Mid-Brunhes Event and West Antarctic ice sheet stability (2011-07)
Holden, P. B.; Edwards, N. R.; Wolff, E. W.; Valdes, P. J. and Singarayer, J. S.
Journal of Quaternary Science, 26(5) (pp. 474-477)

Dimensionally reduced emulation of an AOGCM for application to integrated assessment modelling (2010-11-11)
Holden, P. B. and Edwards, N. R.
Geophysical Research Letters, 37(21) (L21707)

Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials (2010-07-16)
Holden, P. B.; Edwards, N. R.; Wolff, E. W.; Lang, N. J.; Singarayer, J. S.; Valdes, P. J. and Stocker, T. F.
Climate of the Past, 6(4) (pp. 431-443)

A probabilistic calibration of climate sensitivity and terrestrial carbon change in GENIE-1 (2010)
Holden, Philip B.; Edwards, N. R.; Oliver, K. I. C.; Lenton, T. M. and Wilkinson, R. D.
Climate Dynamics, 35(5) (pp. 785-806)

A Bayesian palaeoenvironmental transfer function model for acidified lakes (2008)
Holden, Philip; Mackay, Anson and Simpson, Gavin
Journal of Paleolimnology, 39(4) (pp. 551-566)

ABC for Climate: Dealing with Expensive Simulators (2018-09)
Holden, Philip; Edwards, Neil; Hensman, James and Wilkinson, Richard
In: Sisson, Scott A.; Fan, Yanan and Beaumont, Mark A. eds. Handbook of Approximate Bayesian computation
ISBN : 9781439881514 | Publisher : Chapman and Hall

Fairness in climate negotiations: a meta-game analysis based on community integrated assessment (2015-01-15)
Haurie, Alain; Babonneau, Frederic; Edwards, Neil; Holden, Philip; Kanudia, Amit; Labriet, Maryse; Pizzileo, Barbara and Vielle, Marc
In: Bernard, Lucas ed. The Oxford Handbook of the Macroeconomics of Global Warming (pp. 170-203)
ISBN : 978-0-19-985697-8 | Publisher : OUP USA | Published : New York

Assessing climate impacts on the energy sector with TIAM-WORLD: focus on heating and cooling and hydropower potential (2015-01-01)
Labriet, Maryse; Biberacher, Marcus; Holden, Philip B.; Edwards, Neil R.; Kanudia, Amit and Loulou, Richard
In: Giannakidis, George; Labriet, Maryse; O Gallachoir, Brian and Tosato, GianCarlo eds. Informing Energy and Climate Policies Using Energy Systems Models: Insights from Scenario Analysis Increasing the Evidence Base. Lecture Notes in Energy (30) (pp. 389-409)
ISBN : 978-3-319-16539-4 | Publisher : Springer International Publishing | Published : Cham