John Tyndall
Notes
John Tyndall (1820–1893), Irish physicist at the Royal Institution. In 1859 he measured the absorption of infrared radiation by gases and showed that water vapour and carbon dioxide trap heat while nitrogen and oxygen do not, which is the physical basis of the greenhouse effect and so of climate change. Also explained why the sky is blue and was a prominent agnostic and defender of science against clerical interference.
Wikipedia: https://en.wikipedia.org/wiki/John_Tyndall