A theory that had been dismissed as inadequate was re-examined in 1956: Rising levels of carbon dioxide could be responsible for a warmer climate. “According to a theory which was held half a century ago, variation in the atmosphere’s carbon dioxide can account for climatic change,” Waldemar Kaempffert wrote in The Times on Oct. 28, 1956. “The theory was generally dismissed as inadequate.” According to Dr. Gilbert Plass, “the carbon dioxide theory stands up, though it may take another century of observation and measurement of temperature to confirm it.”

Source: The New York Times