Obituary: Professor David Hall

DAVID HALL was professor of biology at King's College London for 25 years. His professional interests spanned plant physiology, agriculture, forestry, climate change and environmental policy. His favourite research topic was bioenergy - energy released from plant material - a field where he was a pioneer, emphasising that this was one of the most widely available forms of energy and yet one of the least exploited or even recognised.

He could wax lyrical about the productivity of eucalyptus plantations in Brazil, the scope for agroforestry in arid areas of Kenya, and the climate role of carbon pools in the ricelands of India. He started up a journal, Biomass, that has become the pre-eminent publication in the field. He pressed the claims of bioenergy through projects under the United Nations Environment Programme, the World Bank, the European Commission and the Rockefeller Foundation among many other agencies.

After early life in South Africa, where he was born in 1935, David Hall spent several years at the University of California before establishing his main career at King's College London. He was a leading contributor to two working groups of the Intergovernmental Panel on Climate Change, he became Treasurer of the Scientific Committee on Problems of the Environment, and he was Director of the International Solar Energy Society. He was in demand as a visiting professor at universities such as Princeton, Natal and the University of California.

As humanity grapples with one of the biggest transitions in its history, away from fossil fuels and towards clean and renewable energy, biomass (plant material) will surely come to take its place as a prominent source of energy, especially in the tropics. Hall's work will then be acknowledged as a pioneering endeavour with major import for all our energy futures, and he will be accorded the acclaim that he deserved during his lifetime. He has left us at the height of his professional powers, but fortunately with a bequest that should eventually enhance the lives of communities far and wide.

Hall was a strenuous advocate of innovative agriculture. He was convinced the world could feed all its people provided that agricultural science was given its head with stepped-up support (research funding has been declining), and provided that governments pulled the right policy levers. Such was his confidence in the capacity of science to deliver that he believed we could squeeze through the bottlenecks ahead if only we got to grips with the challenges in their full scope.

I first met Professor David Hall at a scientific conference in Thessaloniki, Greece. Professor indeed. He was one of the protagonists at the conference, and I admired his professionalism on all manner of topics. But I said my first extended hello to him on the beach nearby the conference locale, where he was friendliness itself. I was struck that this new acquaintance could be erudite and affable in equal degree.

From then on he was the best of colleagues and the finest of friends, generous of spirit and optimistic by nature. I met him at conference after conference, at his laboratory in King's College, at London theatres and in an Oxford punt. On whatever occasion, he was ready to share his research findings, to discuss his latest activities, and to swap ideas on issues of all sorts. He would drive to Twickenham stadium in one of the ramshackle cars for which he was renowned, holding forth on the phytochemistry of sugar-cane while pondering whether he should cheer for the Springboks or the Brits.

During his final months of illness he flew off to Paris, Budapest, Washington and Tokyo in order to confer with colleagues and to oversee his many field projects. He spent part of his very last day on support work for several of his PhD students. In this, as throughout his life, his prime motivation was - baldly stated - to make his full contribution to shaping a world fit for those who come after.

David Oakley Hall, biologist: born East London, South Africa 14 November 1935; Fellow, John Hopkins Medical School, Baltimore 1963-64; Lecturer in Biology, King's College London 1964-68, Reader 1968-74, Professor 1974- 99; married 1981 Peta Smith (two daughters); died London 22 August 1999.