Global Warming Is Not a Hoax, It`s An Unproved, and Likely Unprovable, Hypothesis

Donald Trump is reported to have said that global warming is a hoax. In fact, the claim that the climate is being warmed due to human activity is not a hoax, but a hypothesis, and quite an old one.

Svante Ahrrenius, in 1896, was the first to quantify the contribution of carbon dioxide to Earth's temperature and to speculate on whether variations in the atmospheric concentration of carbon dioxide have contributed to long-term variations in climate. In later publications he suggested that the combustion of coal would affect global temperature.