75 years ago Callendar published evidence of human impact on the climate

Monday, April 29, 2013

This month marks the seventy-fifth anniversary of a landmark paper, The artificial production of carbon dioxide and its influence on temperature, published in the Royal Meteorological Society. Building on the work of lauded climate scientists, Joseph Fourier, Svante Arrhenius and John Tyndall, amateur weather-watcher and steam engineer, Guy Callendar, was the first to collate temperature measurements from weather stations around the world. His 1938 publication attributed increasing land temperatures to carbon dioxide from fossil fuel combustion. In this paper, Callendar remarked,

Few of those familiar with the natural heat exchanges of the atmosphere, which go into the making of our climates and weather, would be prepared to admit that the activities of man could have any influence upon phenomena of so vast a scale.

While the 1938 paper was published with little fanfare, its significance is being showcased seventy-five years later. Two scientists, Ed Hawkins and Phil Jones have dedicated a co-authored paper (in the same journal) illustrating the accuracy of Callendar’s global land temperature estimates by comparing them with historical reconstructions of near-global land temperatures. This comparison reveals accuracy with modern projections, both reflecting the impressive work of an amateur scientist and providing further validation of modern climate change science. Why it has taken societies seventy-five or more years to pay heed to these critical observations is less about the science and more about socio-economic and political forces, which are slow to admit the incredible influence mankind exerts on “making of our climates and weather”.