about the possibility. He thought it would take 3,000 years for CO2 to double in the atmosphere, and in any event that would be a good thing. He later mused that the increased CO2 concentrations would not only prevent a new ice age but would actively allow mankind to “enjoy ages with more equable and better climates,” especially in “the colder regions of the earth,” and that would “bring forth much more abundant crops than at present for the benefit of rapidly propagating mankind.” And that did not sound at all bad to a lonely Swedish chemist who knew all too well what it was like to live, year after year, through long, dark, cold winters.10
“My grandfather rang a bell, indeed, and people became extremely interested in it at that time,” said his grandson Gustaf Arrhenius, himself a distinguished chemist. “There was a great flurry of interest in it, but not because of the menace, but because it would be so great. He felt that it would be marvelous to have an improved climate in the ‘northern climes.’ And, in addition, the carbon dioxide would stimulate growth of crops—they would grow better. So he and the people at the time were only sad that in his calculations it would take [so long] to have the marked effect.”11
In time, however, attention drifted away from the subject of carbon and climate. Arrhenius himself turned to a number of other topics. In 1903 he was awarded the Nobel Prize in chemistry—not bad for someone whose Ph.D., which initiated the research for which he won the prize, was almost rejected.
In the decades that followed, the world became much more industrialized. Coal was king, both for electric generation and factories, which meant more “carbonic acid”—CO2—going into the air. But there was little attention to climate.
In the Depression years of the early 1930s, drought struck the American Midwest. Poor cultivation techniques had left the topsoil loose and exposed, and winds swept it up into great dust storms, sometimes so intense as to block out the sun, leaving the land barren. The economic devastation drove hundreds of thousands of farm families to pack their belongings on their Model Ts, and, like the fictional Joad family in John Steinbeck’s Grapes of Wrath, living in a “dust-blanketed land,” take to the roads and head to California as migrant refugees from the Dust Bowl. 12
But those droughts were “weather,” not “climate.” No one talked about climate for decades. Or almost no one.
THE EFFECT OF GUY CALLENDAR: CALCULATING CARBON
In 1938 an amateur meteorologist stood up to deliver a paper to the Royal Meteorological Society in London. Guy Stewart Callendar was not a professional scientist, but rather a steam engineer. The paper he was about to present would restate Arrhenius’s argument with new documentation. Callendar began by admitting that the CO2 theory had had a “chequered history.” But not for him. He was obsessed with carbon dioxide and its impact on climate; he spent all his spare time collecting and analyzing data on weather patterns and carbon emissions. Amateur though he was, he had more systematically and fully collected the data than anyone else. His work bore out Arrhenius. The results seemed to show that CO2 was indeed increasing in the atmosphere and that would lead to a change in the climate—more specifically, global warming. 13
While Callendar found this obsessively interesting, he, like Arrhenius, was hardly worried. He too thought this would make for a better, more pleasant world—“beneficial to mankind”—providing, among other things, a boon for agriculture. And there was a great bonus. “The return of the deadly glaciers should be delayed indefinitely.” 14
But Callendar was an amateur, and the professionals in attendance that night at the Royal Meteorological Society did not take him very seriously. After all, he was a steam engineer.
Yet what Callendar described—the role of CO2 in climate change—eventually became known as the Callendar Effect. “His claims rescued the idea of global warming from obscurity and thrust it into the marketplace of ideas,” wrote one historian. But it was only a temporary recovery. For over a number of years thereafter the idea was roundly dismissed. In 1951 a prominent climatologist observed that the CO2 theory of climate change “was never widely accepted and was abandoned.” No one seemed to take it very seriously.15
22
THE AGE OF DISCOVERY
Quite late in his life, Roger Revelle ruminated on his career in science.
“I’m not a very good scientist,” he said. But then he added, “I’ve got a lot of imagination.” One of the