Tim Nicholson, 42, former head of sustainability at Grainger, one of the UK's largest property companies, claims his views on climate change were so serious it led to clashes with other senior staff.
Nicholson, from Oxford, accused Grainger's chief executive, Rupert Dickinson, of showing "contempt" for his concerns, and claimed he once flew a member of staff to Ireland to deliver his BlackBerry which he had left in London.
His case can now go ahead after an employment appeal judge ruled in his favour, based on a ruling that such a strong environmental conviction is akin to a religious belief.
His solicitor, Shah Qureshi, said: "Essentially what the judgment says is that a belief in man-made climate change and the alleged resulting moral imperative is capable of being a philosophical belief and is t