Photo of Dr Anna Harper

Dr Anna Harper

EPSRC LWEC Research Fellow, Proleptic Lecturer in Climate Science


Telephone: 01392 724588

Extension: (Streatham) 4588

Limiting climate change is extremely important for the livelihood of millions of people who live in climate-vulnerable regions, and in December 2016 the world's governments agreed to pursue efforts to limit climate change to below 1.5°C. But at current rates of emission, it will take only 4-13 years to emit the carbon required to get to 1.5°C of warming.

So what can we do? We can and should cut emissions, but we should also investigate strategies for removing CO2 from the atmosphere and their implications for ecosystems and people. One option is bioenergy with carbon capture and storage (BECCS), which delivers dual benefits of carbon sequestration and energy production. However, a large-scale implementation of BECCS will require a massive commitment of land, and it's unknown how productive bioenergy crops could be in the future with climate change.

My current research investigates the potential for negative emissions of CO2 using BECCS and reforestation, and the impacts on food, energy, and water. By quantifying both the mitigation potential and the impacts on food, water, and ecosystems, we aim to assess various scenarios for reducing climate change and their consequences. My research group uses the land surface model JULES to study biogeochemical cycles, vegetation and carbon cycle dynamics, and will be using the UK Earth System Model to study the effects of climate change on bioenergy production and forests, as well as the impacts on climate of large-scale land use change for bioenergy and carbon sequestration.

My work is funded by an EPSRC Living With Environmental Change fellowship (2016-2019), the NERC grants "Climate, Land-Use, and Ecosystem Services for 1.5C", and "Feasibility of Afforestation and Biomass energy with carbon capture and storage for Greenhouse Gas Removal (FAB-GGR)".

Other research interests

I am particularly interested in the Amazon rainforest, an amazing ecosystem which provides invaluable services to humanity - not least of which is the storage of CO2. Drought threatens this ecosystem. How the forest responds to droughts and the likelihood of future droughts will both play large roles in the future of the global carbon cycle and climate. 

CO2 Fertilization

Plants "eat" CO2 to live, so to first order vegetation will benefit from growing atmospheric CO2 concentrations. In reality, there are several complicating factors which will control how much extra CO2 plants can assimilate: changes in weather and climate patterns, changes in nutrient availability, and human land use change and degradation. I'm involved in a project to better understand how plants will respond to rising CO2 using "FACE" (free-air enrichment of CO2) experiments. During these experiments, extra CO2 is pumped into a study area and the responses of the plants and soils are measured. My role is to use JULES to see which processes might be most important in the real world that are missing in earth system models. There is an exciting new FACE project at the University of Birmingham, BiFor FACE.

The global carbon budget

Simulations by Andy Wiltshire (UK Met Office) and I using the JULES land surface model contributed to the 2013 global carbon budget, read the summary here:


Recent Publications (please e-mail me if you would like a copy but do not have access to a journal)


De Kauwe, M., et al, Challenging terrestrial biosphere models with data from the long-term multi-factor Prairie Heating and CO2 Enrichment experiment. Global Change Biology

Williams, K., et al. Evaluation of JULES-crop performance against site observations of irrigated maize from Mead, Nebraska, Geoscientific Model Development Discussions.


AB Harper et al., Improved representation of plant functional types and physiology in the Joint UK Land Environment Simulator (JULES v4.2) using plant trait information. Geoscientific Model Development.

Ryan, EM et al. Gross primary production responses to warming, elevated CO2, and irrigation: quantifying the drivers of ecosystem physiology in a semiarid grassland. Global Change Biology.

Mangeon, S. et al. INFERNO: A fire and emissions scheme for the UK Met Office's Unifed Model, Geoscientific Model Development.

Calle, L. et al. Regional carbon fluxes from land use and land cover change in Asia, 1980-2009, Environmental Research Letters.


JM Osborne, FH Lambert, AB Haprer, M Groenendijk, S Sitch, CD Koven, B Poulter, TAM Pugh, BD Stocker, A Wiltshire, S Zaehle (2015), Reconciling precipitation with runoff: observed hydrological changes in mid-latitudes. Journal of Hydrometeorology.

P Good, AB Harper, A Meesters, E Robertson, R Betts (2015), Are strong fire-vegetation feedbacks needed to explain the spatial distribution of tropical tree cover? Accepted to Global Ecology and Biogeography.

A Anav, P Friedlingstein, C Beer, P Ciais, A Harper, C Jones, G Murray-Tortarolo, D Papale, NC Parazoo, P Peylin, S Piao, S Sitch, N Viovy, A Wiltshire, M Zhao (2015): Spatio-temporal patterns of terrestrial gross primary production: A Review. Review of Geophysics.

G Murray-Tortarolo, P Friendlingstein, S Sitch, VJ Jaramillo, F Murguia-Flores, A Anav, Y Liu, A Arneth, A Arvanitis, AB Harper, A Jain, E Kato, C Koven, B Poulter, BD Stocker, A Wiltshire, S Zaehle, N Zeng (2015): The carbon cycle in Mexico: past, present, and future of C stocks and fluxes. Biogeosciences Discussions.

NC Parazoo, E Barnes, J Worden, AB Harper, KW Bowman, C Frankenberg, S Wolf, M Litvak, TF Keenan (2015): Influence of ENSO and the NAO on terrestrial carbon uptake in the Texax-northern Mexico region. Global Biogeochemical Cycles.  

Rowland, L., AB Harper, B. O. Christoffersen, D. R. Galbraith, H. M. A. Imbuzeiro, T. L. Powell, C. Doughty, N. M. Levine, Y. Malhi, S. R. Saleska, P. R. Moorcroft, P. Meir, and M. Williams, (2015) Modelling climate change responses in tropical forests: similar productivity estimates across five models, but different mechanisms and responses. Geoscientific Model Development.


AB Harper, IT Baker, AS Denning, DA Randall, D Dazlich, M Branson, (2014) Impact of evapotranspiration on dry season climate in the Amazon forest. Journal of Climate.

- Press release:

C. Le Quéré and co-authors, (2013), Global carbon budget 2013. Earth Syst. Sci. Data Discuss. 6, 689-760.


IT Baker, AB Harper, HR Rocha, AS Denning, AC Araujo, LS Borma, HC Freitas, ML Goulden, AO Manzi, SD Miller, AD Nobre, N Restrepo-Coupe, SR Saleska, R Stockli, C Randow, SC Wofsy (2013), Surface ecophysiological behavior across vegetation and moisture gradients in tropical South America. Agricultural and Forest Meteorology.

TL Powell, DR Galbraith, BO Christoffersen, AB Harper, HMA Imbuzeiro, L Rowland, S Almeida, PM Brando, ACL da Costa, MH Costa, NM Levine, Y Malhi, SR Saleska, E Sotta, M Williams, P Meir, PR Moorcroft (2013), Confronting model predictions of carbon fluxes with measurements of Amazon forests subjected to experimental drought. New Phytologist. 


AB Harper, AS Denning, IT Baker, MD Branson, L Prihodko, DA Randall (2010), Role of deep soil moisture in modulating climate in the Amazon forest. Geophysical Research Letters.