In 1958, a scientist named Dr. Charles David Keeling invented an unusual object that caught the attention of the scientific world. The instrument Keeling designed and built was called a manometer, and its purpose was to measure levels of atmospheric carbon dioxide (CO2). Like all scientists, Keeling knew that CO2 and other gases existed naturally in the earth's atmosphere. He suspected, though, that CO2 levels were steadily growing higher. Since the Industrial Revolution, a period of rapid industrial growth in Europe and America during the eighteenth and nineteenth centuries, manufacturing had flourished. This caused more CO2 than ever before to be pumped into the air. Keeling suspected that this might be lingering in the atmosphere, and some scientists agreed with him. However, until the invention of the manometer there was no way to measure CO2 levels, so no one...