Science
An engineer warned about man-made global warming in 1938 — and was ignored
Guy Stewart Callendar was a steam engineer, not a climatologist, when he compiled global temperature and CO2 records and argued fossil-fuel emissions had already warmed the planet's land by about 0.3°C. Most meteorologists at the time dismissed him as an outsider. Retrospective studies decades later found his hand-calculated estimates were remarkably close to the real numbers.