BBC: Seventy-five years ago an amateur scientist made a breakthrough discovery in the field of climate change.
Guy Stewart Callendar linked global warming to CO2 emissions but his work went largely unnoticed at the time.
Now the anniversary of his discovery has been commemorated by two leading climate scientists.
Prof Phil Jones, from the University of East Anglia in Norwich, and Dr Ed Hawkins, from the University of Reading, have published a paper looking at Callendar's legacy.
Prof Jones...