Write a commentPresident Lyndon B. Johnson addressed Congress a few weeks after his inauguration in 1965.
President Johnson told Congress, "This generation has altered the composition of the atmosphere on a global scale through a steady increase in carbon dioxide from the burning of fossil fuels."
Near the end of his first year in office, President Johnson's Science Advisory Committee warned the President (and the world) what the impact of a steady increase in CO₂ would be. "The climatic changes that may be produced by the increased CO₂ content could be deleterious from the point of view of human beings."
In 1977, the Department of Energy asked a committee of elite scientists, the Jasons, to review the Department of Energy's research on CO₂. The Jasons committee of elite scientists demonstrated that if the CO₂ in the atmosphere doubled, it would lead to "an increase of average surface temperature of 2.4 °C." It was a startling admission, but the Jasons predicted that warming at the polar ice caps could reach a petrifying temperature increase of 12°C.
The climate model provided by the Jasons was followed up by a report by an arm of the National Academy of Sciences. In that same year, the National Research Council had a committee led by Robert M. White. The committee for the National Research Council knew in 1977, "industrial wastes, such as carbon dioxide released during the burning of fossil fuels, can have consequences for the climate that pose a considerable threat to future society."
By 1977, a portion of the scientific community recognized that global warming wasn't a crisis for the future; it was a crisis now. By the 1980s, the Climate Research Board asked Bill Nierenberg to develop and lead what would be named the Carbon Dioxide Assessment Committee. They released their findings in a 519-page report. "There is widespread agreement that anthropogenic carbon dioxide emissions have been rising steadily, primarily driven by the combustion of fossil fuels."
Chapter 8 of the report provided evidence that an increase in CO₂ in the atmosphere destabilized the West Antarctic Ice Sheet. It was disintegrating, and if CO₂ levels continued to rise, it would raise global sea levels. "The resulting worldwide rise in sea level would be between 5 and 6 m. The oceans would flood all existing port facilities and other low-lying coastal structures, extensive sections of the heavily farmed and densely populated river deltas of the world, major portions of the state of Florida and Louisiana, and large areas of many of the world's major cities."
The mayors of major coastal cities took the threat to hundreds of millions of people seriously. A global network of nearly 100 mayors of the world's leading cities formed a group called C40. They used the reports by the World Bank, NASA, Britain's Royal Society, the U.S. National Academy of Sciences, and the International Energy Agency to conclude that by 2050, over 800 million people would live in 570 cities that rising sea levels would erase.
