Born on 22 February 1953 in Karima, Sudan. Received MSc (1988) & PhD (1989) from Iowa State University, USA; BSc (1977) & MSc (1983) from Univ. of Khartoum, Sudan; Currently Professor and Director of the Centre for Environmental Economics and Policy in Africa (CEEPA), Faculty of Natural and Agricultural Sciences, University of Pretoria (since 1997) and previously Program Director at CSIR, South Africa (1995-1997), Regional Economist at CIMMYT International (1992-1995); Rockefeller Fellow post-doc (1990-1992); Iowa State, Khartoum and Juba universities before that.

Served as a member of many national and international advisory boards & committees including: The CGIAR Independent Science and Partnership Council - ISPC (2010), the Human Sciences Research Council (HSRC) of SA (2009), The South African Forestry Company-SAFCOL (since 2007), CGIAR Climate Change Challenge Program (CCCP) Steering Committee (2008-2010), External Academic Advisory Panel For The World Development Report 2009 On Climate Change, World Bank (2008-09), Steering Committee of The African Centre For Climate and Earth Stewardship Science - ACCESS (2008-present), Stockholm Resilience Centre Board of Directors (2006-present), GEF Science and Technical Advisory Panel-STAP IV (2005), Science Panel and Co-Chair of the Condition and Trends Working Group of the Millennium Ecosystem Assessment (2005-2007) Leader of the Africa-Wide GEF/World Bank Funded Project On: Impacts of climate change on agriculture, water and ecosystems; Academy of Science of South Africa (2005-2008); Elected Senior Fellow of the African Association of Agric Economists (2010), Elected Fellow of the Academy of Sciences for the Developing World - TWAS (2010), Two times recipient of the Univ. of Pretoria "Achiever: Academic Excellence" (2005, 2008); Senior Associate, Program on Ecological And Environmental Economics (EEE), Abdus Salam International Centre for Theoretical Physics-ICTP, (2003-2005); Associate editor and member of Editorial Boards of many international and regional journals: Founding Chief Editor of the African Journal of Agric and Resource Economics, More than 140 refereed publications including 12 books (Edward Elgar, RFF, Cab Int., Island Press, Earth Scan, Springervelag).