Roger Gordon’s plans for ammonia could be a central component of a carbon-free future. Advocates of America’s Green New Deal or other radical efforts to decarbonize the world economy in the face of a looming climate crisis may well have one of their greatest champions in a rumpled 65-year-old who lives in the Toronto suburbs. Roger Gordon wears a navy wool coat that extends well past the bottom of his green knit sweater on a chilly day in February. He talks with a quintessentially Canadian politeness as he rails against what he sees as a massive conspiracy to suppress his...