Sir Crispin Tickell, who has died of pneumonia aged 91, was a career diplomat. He advised four prime ministers, had formidable intellect and displayed impeccable timing when intervening in policy. For example, when John Major was desperate for a big idea to present to the Earth Summit in Rio in 1992 to help the UK seem visionary, Tickell reached into his briefcase and pulled out his plan for the Darwin Initiative, a scheme to protect biodiversity in the poorest countries. He had been working on the idea for some time and been waiting for the right moment to appear. Major was delighted with it, the scheme was launched in a speech at Rio and Tickell became the first chair of its advisory committee. In a long career he had often found himself in the right place at the right time. In 1956, as a junior Foreign Office official, he dispatched a Royal Navy destroyer to deter a threatened Argentinian invasion of the Falkland Islands, an intervention that was successful.
He was involved in many negotiations on behalf of the British government, from arms control with the Russians, to entry talks to the European Community in 1972. But perhaps his greatest contribution to forming policy was on the environment. In 1977, while taking a sabbatical at Harvard he wrote Climatic Change and World Affairs. This was one of the first, and for at least a decade, the only book on the coming climate crisis, and what governments should do to prevent it. He argued for mandatory international pollution control, something that is finally taking shape. Margaret Thatcher credited him with convincing her of the science of global warming and the danger that it posed for the planet, which resulted in her speech on the subject to the Royal Society in September 1988. This brought climate change into the mainstream of British politics. Tickell was also concerned with the controversial subject of world population and the fact that extra billions of people were inevitably going to cause problems for biodiversity and the climate. But rather than draconian measures to curb population growth his emphasis was on being positive – better reproductive health, education for women and lifting millions out of poverty. He thought economic security was the best way to reduce family size. Whenever the government position allowed him to do so he helped to steer environment goals in the right direction – and was proud of his successful efforts as permanent secretary at the Overseas Development Administration (1984-87) to put an end to all aid for anything to do with tobacco. Tickell was born in London, the son of the writer and historian Jerrard Tickell and his wife, Renée (nee Haynes), also a writer. Their son was described early in his career as one of the brightest men of his generation, attending Westminster school and graduating from Christ Church, Oxford in 1952 with a first in modern history. He then went straight into the Coldstream Guards as a second lieutenant to do his national service before joining the Foreign Office in 1954. His first job was to look after the British Antarctic Territory, something that was strongly linked to the politics of South America and the Falklands, but was also central to the academic study of this pristine wilderness and the science of climate. There followed a series of postings to British embassies as his career progressed, including The Hague, Mexico City and Paris. By 1970 he was private secretary to various chancellors of the Duchy of Lancaster and his impressive grasp of detail was found to be vital in the negotiations for the UK entry into the European Community. He married Chloe Gunn in 1954 and they had two sons and a daughter. The marriage ended in divorce in 1976. Tickell’s career continued to prosper and a second posting to Mexico was as ambassador, a job that allowed him to indulge his passion for studying the pre-Columbian art of the region. It was during that posting that the Queen knighted him, in 1983, on board the Royal Yacht Britannia while she was on an official visit to the country. His final diplomatic post was as British ambassador to the United Nations and permanent representative on the UN Security Council from 1987 until 1990. It was in this post that he played an active part in the talks to end the Iran/Iraq war. But in no sense did Tickell retire after that. He chaired Major’s government panel on Sustainable Development from 1994 until 2000 and was a member of two Labour government taskforces. He returned to Oxford to be warden of Green College from 1990 to 1997 and was chancellor of the University of Kent from 1996 to 2006. He became president of the Royal Geographical Society (1990-93) and of the Marine Biological Society (1990-2001). He found time in 1996 to write a biography of Mary Anning, the now celebrated Lyme Regis fossil hunter who was his great-great aunt, and he continued to give lectures on a variety of subjects well into his 80s. Tickell was showered with honorary degrees and fellowships in the UK, US and in Europe, and had a minor planet and a Mexican volcano named after him. In 1989 he was appointed GCMG. All his life he believed in staying fit, being a cycling commuter on a folding bike from his home in St John’s Wood to the Foreign Office, and latterly going on long walks near his home, a converted barn in the Cotswolds. True to the civil service tradition he always remained politically neutral. He is survived by his second wife, Penelope (nee Thorne), whom he married in 1977, and the two sons, James and Oliver, and daughter, Oriana, from his first marriage. • Crispin Charles Cervantes Tickell, diplomat and academic, born 25 August 1930; died 25 January 2022