Willis Carrier
Willis Haviland Carrier (November 26, 1876 – October 7, 1950) was an American engineer, best known for inventing modern air conditioning. Carrier invented the first electrical air conditioning unit in 1902. In 1915, he founded Carrier Corporation, a company specializing in the manufacture and distribution of heating, ventilation, and air conditioning (HVAC) systems.
Guy Stewart Callendar
Guy Stewart Callendar (; February 1898 – October 1964) was an English steam engineer and inventor. His main contribution to knowledge was developing the theory that linked rising carbon dioxide concentrations in the atmosphere to global temperature. This theory, earlier proposed by Svante Arrhenius, has been called the Callendar effect. Callendar thought this warming would be beneficial, delaying a "return of the deadly glaciers."