Early Climate Science

People have been interested in the weather for centuries, but scientists have only had the tools to study climate for about 200 years.  The idea that the global climate has changed over millennia emerged about 170 years ago from research by geologists and paleontologists.  Examination of fossil remains by early paleontologists led them to realize that animals they thought of as warm-climate creatures had once lived in northern Europe.  They debated whether the climate of Europe had been different, or whether the fossil animals had adapted to live in a colder environment.

Geologists who studied glaciers and their activity in shaping the Alps settled the question.  In the late 1830s, Louis Agassiz and other geologists discovered that much of Europe had once been covered by glaciers.  This discovery led to a realization that earth’s climate was much warmer in the nineteenth century than it had been in the past.  Agassiz’s work on the Ice Age made him a celebrity and launched scientific interest in paleoclimatology.

Although Agassiz and his colleagues knew the climate could change, they did not understand how or why. A group of physicists in the late nineteenth century supplied the next pieces of the puzzle. Joseph Fourier and John Tyndall conducted work on the greenhouse effect, explaining how gases in the atmosphere both trap and conducts heat from the sun. In 1896, Svante Arrhenius made the connection between human activity and the greenhouse effect, calculating that doubling the carbon dioxide in the atmosphere through industrial activity would raise the global temperature by about 4 degrees Celsius.