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Alexander Koch


IMG_20160813_171859.jpgDepartment of Geography
University College London
Pearson Building
Gower Street






Primary: Dr Chris Brierley (UCL)

Secondary: Prof Simon Lewis (UCL)





Current Research

The 7-10 ppm decrease in atmospheric CO2 between 1550 and 1650 is the largest pre-industrial change in CO2 over the past 2,000 years. Natural forcing and natural feedback mechanisms appear not to explain either the full magnitude or the short time period of the CO2 drop. Recent studies therefore suggest that the collapse of the indigenous Meso- and South American population after 1492 and land cover change due to near-cessation of farming thereafter contributed significantly to decreasing CO2 concentrations. Uncertainties in population dynamics and land use patterns prevented climate modelling efforts so far from adequately resolving the magnitude of anthropogenic influence on the CO2 anomaly. This PhD will bridge the gaps between climate modelling, archaeology and tropical vegetation science by combining updated regional population estimates, land use practices and ecological feedbacks on farming abandonment to improve an anthropogenic land cover change dataset (HYDE 3.1). This will then be used to force an Earth System model (HadGEM2-ES) to model carbon fluxes and climatic feedbacks from the Columbian depopulation. The results of this modelling study will contribute to efforts in dating the beginning of the Anthropocene by determining the degree of anthropogenic contribution on pre-industrial variations in the carbon budget and climate.



  1. Review current anthropogenic land cover change datasets against archaeological, historical and paleoecological evidence
  2. Creation of an “best-estimate” land use dataset for 1500 based on existing ALCC dataset and recommendations from Objective 1 to be used in Earth System model
  3. Analyse the effects of neotropical reforestation from 1500 to 1650 on the global carbon cycle in an Earth System model
  4. Analyse the ocean carbon cycle feedback to abrupt variations in atmospheric CO2 with an simplified ocean carbon cycle model


Academic Qualifications

2014-present University College London, United Kingdom

PhD “Modelling climate and carbon cycle feedbacks from large scale neotropical reforestation following 16th-century Columbian depopulation events


2011–2012 King’s College London, United Kingdom

MSc Global Environmental Change

Thesis title: “The effects of the London 2012 Olympic Games on air pollution”


2007–2010 Philipps-University Marburg, Germany

BSc Geography

Thesis title: “Geoarchaeological investigations on Dumat Al-jandal, Saudi Arabia”



2013-2014 Centre for Environment, Fisheries and Aquaculture Science (Cefas)



Grants & Summer Schools

London NERC DTP studentship award

NCAS Climate Modelling Summer School 2015

Teaching & other activities

Teaching Assistant, Department of Geography, UCL (2015-Present)

GEOG3063: Overseas Fieldclass Greece

GEOG2005: Geomorphology

GEOGG065: Environmental GIS

GEOGG134: Climate Modelling

NERC DTP Core Training


Co-organiser of the joint London NERC DTP & SSCP Imperial DTP PhD student conference 2016 “Perspectives on Environmental Change”



Conference Presentations

-       Oral Presentations

Perspectives on Environmental Change DTP conference September 2016

“16th-century America’s population demise, land use and carbon cycle changes”

-       Poster Presentations

ICES Annual Science Conference, 2013, Reykjavik, Iceland

“Modelling framework for the assessment of human impacts on marine seabed”