Julian gained a PhD on climate change impacts and adaptation in the School of Earth and Environment at University of Leeds in early 2014. Prior to that he worked in the International Center for Tropical Agriculture (CIAT) as a research assisstant on crop-climate interactions and crop modelling. He is now working as a postdoctoral research fellow in the School of Earth and Environment, at the University of Leeds, in the Climate Impacts Group led by Prof. Andy Challinor. He also works in the Decision and Policy Analysis program at the International Center for Tropical Agriculture (CIAT), through a Leeds-CIAT joint position funded by the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS).

During his career, Julian has contributed to a broad range of research projects at CCAFS and CIAT and has published a number of papers related to crop-climate modelling, climate change impacts, adaptation, conservation of biodiversity and plant genetic resources.


  • PhD, "Genotypic adaptation of Indian groundnut cultivation to climate change: an ensemble approach", University of Leeds, UK, 2014
  • B. Eng. (Hons), Agricultural Engineering, Universidad Nacional de Colombia, Colombia

Research Interests

Julian's current research focuses on climate change impacts and adaptation, as well as on the assessment of inherent uncertainties in impacts and adaptation projections. In particular, on understanding whether robust statements on impacts and adaptation can be made despite uncertainties in crop-climate modelling frameworks. Developing an understanding of where uncertainties lie, how they can be reduced and which processes are important for coherent projections of future crop yields and food availability is a key part of his work. This also invoves crop model development and improvement, particularly with the General Large Area Model for annual crops (GLAM), which we maintain and develop here at Leeds.

He is also investigating the dimensions of potential cropping system transformations in Sub-Saharan Africa, and is involved in the development of a crop-climate forecasting system for Colombian direct rice seeding systems.

Teaching Interests

In 2015 Julian started giving a lecture entitled "Projection-based frameworks for informing adaptation" for the module Monitoring Climate Change: Past, Present and Future in the MSc course Climate Change, Agriculture and Food Security of University of Galway, in Ireland.


Journal articles

  • Heinemann, A.B., Barrios, C., Ramirez-Villegas, J., Arango, D., Bonilla-Findji, O., Medeiros, J.C., and Jarvis, A. 2015. Variation and impact of drought stress patterns across upland rice target population of environments in Brazil. Journal of Experimental Botany, doi: 10.1093/jxb/erv126.
  • Ramirez-Villegas, J., Watson, J., and Challinor, A.J. 2015. Identifying traits for genotypic adaptation using crop models. Journal of Experimental Botany, doi: 10.1093/jxb/erv014.
  • Khoury, C.K., Castaneda-Alvarez, N.P., Achicanoy, H., Sosa, C.C., Bernau, V., Kassa, M.T., Norton, S.T., van der Maesen, J., Upadhyaya, H.D., Ramirez-Villegas, J., Jarvis, A., and Struik, P.C. 2015. Crop wild relatives of pigeonpea [Cajanus cajan (L.) Millsp.]: distributions, ex situ conservation status, and potential genetic resources for abiotic stress tolerance. Biological Conservation, 184: 259-270, doi: 10.1016/j.biocon.2015.01.032
  • Challinor, A.J., Parkes, B., and Ramirez-Villegas, J. 2015. Crop yield response to climate change varies with cropping intensity. Global Change Biology, 21(4): 1679-1688, doi: 10.1111/gcb.12808
  • Ramirez-Villegas, J., Cuesta, F., Devenish, C., Peralvo, M., Jarvis, A., and Arnillas, C.A. 2014. Species distributions modeling for assessing conservation needs of Tropical Andean biodiversity under climate change.Journal for Nature Conservation, 22(5): 391-404, doi: 10.1016/j.jnc.2014.03.007.
  • Polce, C., Garrat, M.P., Termansen, M., Ramirez-Villegas, J., Lappage, M., Challinor, A.J., Melese-Endalew, A., Potts, S.G., Somerwill, K.E., and Biesmeijer, J.C. 2014. Climate-driven spatial mismatches in British orchards and their pollinators increase risks of deficits in pollination services. Global Change Biology, 20(9): 2815-2828, doi: 10.1111/gcb.12577
  • Khoury, C.K., Bjorkman, A.D., Dempewolf, H., Ramirez-Villegas, J., Guarino, L., Reiseberg, L.H., Jarvis, A., and Struik, P. 2014. Increasing homogeneity in global food supplies and the implications for food security.Proceedings of the National Academy of Sciences, 111(11): 4001-4006,doi: 10.1073/pnas.1313490111.
  • Ramirez-Villegas, J., and Khoury, C.K. 2013. Reconciling approaches to climate change adaptation for Colombian agriculture. Climatic Change, 119(3-4): 575-583, doi: 10.1007/s10584-013-0792-6.
  • Vermeulen, S.J., Challinor, A.J., Thornton, P.K., Campbell, B.M., Eriyagama, N., Vervoort, J., Kinyangi, J., Jarvis, A., Laderach, P., Ramirez-Villegas, J., Nicklin, K., Hawkins, E., and Smith, D. 2013. Addressing uncertainty in adaptation planning for agriculture. Proceedings of the National Academy of Sciences, 110(21): 8357-8362, doi: 10.1073/pnas.1219441110.
  • Warren, R.F., VanDerWal, J., Price, J., Welbergen, J., Atkinson, I., Ramirez-Villegas, J., Osborn, T., Jarvis, A., Shoo, L., Williams, S., and Lowe, J. 2013. Quantifying the benefit of early climate change mitigation in avoiding biodiversity loss. Nature Climate Change, 3: 678-682, doi:10.1038/nclimate1887.
  • Ramirez-Villegas, J., Challinor, A.J., Thornton, P.K., and Jarvis, A. 2013. Implications of regional improvement in global climate models for agricultural impact research. Environmental Research Letters, 8: 024018, doi: 10.1088/1748-9326/8/2/024018
  • Cortes, A.J., Monserrate, F., Ramirez-Villegas, J., Madrinan, S., and Blair, M.W. 2013. Drought Tolerance in Wild Plant Populations: the Case of Common Beans (Phaseolus vulgaris L.). PLoS ONE, 8(5): e62898,doi:10.1371/journal.pone.0062898.
  • Glenn, M., Kim, S. H., Ramirez-Villegas, J., and Laderach, P. 2013. Response of Perennial Horticultural Crops to Climate Change. Horticultural Reviews, 41, ISBN: 978-1-1187-0737-1.
  • Ramirez-Villegas, J., Jarvis, A., and Laderach, P. 2013. Empirical Approaches for Assessing Impacts of Climate Change on Agriculture: The EcoCrop Model and a Case Study with Grain Sorghum. Agricultural and Forest Meteorology, 170: 67-78, doi: 10.1016/j.agrformet.2011.09.005
  • Ramirez-Villegas, J., Jarvis, A., and Touval, J.2012. Analysis of threats to South American flora and its implications for conservation. Journal for Nature Conservation, 20: 337-348, DOI:10.1016/j.jnc.2012.07.006
  • Ramirez-Villegas, J., Salazar, M, Jarvis, A. and Navarro-Racines, C.E. 2012. A way forward on adaptation to climate change in Colombian agriculture: Perspectives towards 2050. Climatic Change, 115(3-4): 611-628,DOI: 10.1007/s10584-012-0500-y
  • Ramirez-Villegas, J., and Challinor, A. J. 2012. Assessing Relevant Climate Data for Agricultural Applications.Agricultural and Forest Meteorology, 121: 26-45, doi: 10.1016/j.agrformet.2012.03.015
  • Jarvis, A., Ramirez-Villegas, J., Herrera Campo, B.V., and Navarro-Racines, C.E. 2012. Is Cassava the Answer to African Climate Change Adaptation? Tropical Plant Biology,5(1): 9-29, doi:10.1007/s12042-012-9096-7.
  • Van den Bergh, I., Ramirez, J., Staver, C., Turner, D., Jarvis, A., and Brown, D. 2012. Climate Change in the Subtropics: Impacts of Projected Averages and Variability on Banana Productivity. Acta Horticulturae (ISHS)928: 89-99.
  • Mulligan, M.; Fisher, M., Sharma, B., Ringler, C., Mahé, G., Jarvis, A., Ramírez, J., Clanet, J-C., Ogilvie, A., and Ahmad M-u-D. 2011. The nature and impact of climate change in the Challenge Program on Water and Food (CPWF) basins. Water International, 36(1): 96-124. DOI:10.1080/02508060.2011.543408
  • Ramirez-Villegas, J., Khoury, C., Jarvis, A. Debouck, D.G., and Guarino, L. 2010. A Gap Analysis Methodology for Collecting Crop Genepools: A Case Study with Phaseolus Beans. PLoS ONE 5(10): e13497.doi:10.1371/journal.pone.0013497
  • Schroth, G., Laderach, P., Depenwolf, J. Philpott, S., Haggar, J., Eakin, H., Castillejos, T., Garcia-Moreno, J., Soto-Pinto, L., Hernandez, R., Eitzinger, A., and Ramirez-Villegas, J. 2009. Towards a climate change adaptation strategy for coffee growing communities and ecosystems in the Sierra Madre de Chiapas, Mexico.Mitigation and Adaptation Strategies for Global Change, 14(7): 605-625, DOI: 10.1007/s11027-009-9186-5.

Book chapters

  • Berry, P., Ramirez-Villegas, J., Bramley, H., Mgonja, M., and Mohanty, S. 2013. Regional Impacts of Climate Change and the role of Adaptation. In: Jackson, M., Ford-Lloyd, B., Parry, M. (Eds.) Plant Genetic Resources and Climate Change. CABI publishing. ISBN: 978-17-0641973.
  • Mathur, P.N., Ramirez-Villegas, J., Jarvis, A. 2012. The Impacts of Climate Change on Tropical and Subtropical Horticultural Production. In: Sthapit, B.R., Ramanatha Rao, V., Sthapit, S.R. (Eds.) Tropical Fruit Tree Species and Climate Change. Bioversity International, New Delhi, India. ISBN: 978-92-9043909.
  • Ramirez-Villegas, J., Jarvis, A., Hanson, J., Leibing, C., and Fujisaka, S. 2012. Crop and Forage Genetic Resources: International Interdependence in the Face of Climate Change. In: Halewood, M., López Noriega, I, Louafi, S. (Eds.) Crop Genetic Resources as a Global Commons: Challenges in international law and governance. Routledge, Taylor and Francis Group, London and New York. ISBN: 978-0-84407-893-6.
  • Ramirez, J., Jarvis, A., Van den Bergh, I., Staver, C., and Turner D. 2011. Chapter 20: Changing Climates: Effects on Growing Conditions for Banana and Plantain (Musa spp.) and Possible Responses. In: Yadav, S., Redden, B. Hattfield, J.L., and Lotze-Campen, H. (Eds.) Crop Adaptation to Climate Change. Wiley-Blackwell.ISBN: 978-0-8138-2016-3.
  • Beebe, S., Ramirez, J., Jarvis, A., Rao, I.M., Mosquera, G., Blair, M., and Bueno, J.M. 2011. Chapter 16: Common Beans and the Challenges of Climate Change. In: Yadav, S., Redden, B. Hattfield, J.L., and Lotze-Campen, H. (Eds.) Crop Adaptation to Climate Change. Wiley-Blackwell. ISBN: 978-0-8138-2016-3.
  • Ceballos, H., Ramirez, J., Belloti, A.C., Jarvis, A., and Alvarez, E. 2011. Chapter 19: Adaptation of Cassava to Changing Climates. In: Yadav, S., Redden, B. Hattfield, J.L., and Lotze-Campen, H. (Eds.) Crop Adaptation to Climate Change. Wiley-Blackwell. ISBN: 978-0-8138-2016-3.
  • Schaefleitner, R., Ramirez, J., Jarvis, A., Evers, D., Gutierrez, R., and Scurrah, M. 2011. Chapter 11: Adaptation of the Potato Crop to Changing Climates. In: Yadav, S., Redden, B. Hattfield, J.L., and Lotze-Campen, H. (Eds.) Crop Adaptation to Climate Change. Wiley-Blackwell. ISBN: 978-0-8138-2016-3.
  • Laderach, P.; Lundy, M.; Jarvis, A.; Ramírez J., Perez Portilla, E., Schepp, K., Eitzinger, A. 2011. Predicted Impact of Climate Change on Coffee Supply Chains. 703–723. In: Leal Filho, W. (Ed.) The Economic, Social and Political Elements of Climate Change. Springer Verlag, Berlin. ISBN: 978-3-642-14775-3.
  • Jarvis, A., Ramirez, J., Anderson, B., Leibing, C., and Aggarwal, P. K. 2010. Chapter 2: Scenarios of climate change within the context of agriculture. In: Reynolds, M. 2010. Climate Change and Crop Production. CABI publishing. ISBN: 978-1-84593-633-4
  • Läderach, P.; Kathleen, S.; Ramirez, J.; Jarvis, A.; and Eitzinger, A. 2010. Impacto del cambio climático para el cultivo de café en Nicaragua. In: Martinez, C. (Ed.) Adaptación al cambio climático y servicios ecosistémicos en América Latina. Centro Tropical agronómico Tropical de Investigación y enseñanza (CATIE). Turrialba, Costa Rica. 145 pp. Publicación CATIE no. 99. ISBN: 978-997-7575-278