My father, Brian Orr, who has died aged 88, was a scientist, a civil servant and an activist in the London Federation of Green Parties. He had predicted the impact of global climate change from his youth in the 1950s, his ongoing theme being the loss of biodiversity.
Having joined the party when it was the Ecology party in 1982, he played a crucial role in restarting Brent Green party as an effective political body in the 1990s: as party chair and election agent he ensured that candidates stood in all elections; he stood as a candidate twice himself and was treasurer for the federation when Noel Lynch was chair.
Brian was born in Portsmouth to Thomas Orr, who worked in communications at the Royal Navy Admiralty in London, and Daphnea (nee Wilson), an executive officer at the Ministry of Defence. His childhood involved frequent relocation. Thomas was posted abroad at the height of the siege of Malta and his young family sheltered from the bombing in the Maltese catacombs. In 1940 they moved to South Africa; the Drakensberg mountains were where Brian’s fascination with wildlife began.
Returning to Portsmouth in 1944, Brian did a milk round on Portsdown Hill and won a scholarship to Portsmouth grammar school. He completed an electrical engineering apprenticeship at the Signals Research and Development Establishment in Christchurch, Dorset, then graduated from Nottingham University in 1959 with a degree in electrical engineering. He married Marilyn, a fellow student, and finished his PhD at Nottingham while they started a family.
In 1963 Brian took the family to Australia as “ten pound poms”. He worked alongside other world-class engineers on the Snowy Mountain scheme, a gigantic hydroelectricity complex, living in Cooma, then a small township in New South Wales, in a corrugated-tin house on stilts. In 1965 they were forced to return home for a diagnosis for their eldest son, Richard; it was eventually established that he was severely autistic.
Brian then worked as a researcher at the Military Engineering Experimental Establishment in Christchurch, Dorset, and in 1976 became a principal scientific officer in the Department of the Environment. Brian and Marilyn divorced in the 1980s and he later met Liz Caesar, a civil service colleague; they married in 2007.
On his retirement in 1995 he was finally able to commit himself full time to the Greens and find joy with Liz, his garden, his rescue cats and teaching bridge to a local group.
Brian is survived by Liz, his children, Richard, Joe and me, and his nephew David and niece Kate.