Timeline

—5 Billion Years Ago: Planet Earth forms 

—10,000 years ago: Last Ice Age ends

—1500-1850: Little Ice Age occurs, temperatures in Northern Hemisphere drop by approximately 1 degree Celsius, triggering disease and famine.

—Mid-1700s: Industrial Revolution begins and manual labor-based economy is replaced by industry and coal-burning machinery.

—1824: French mathematician and physicist Joseph Fourier discovers that atmospheric gases could raise the Earth’s surface temperature. His observations would later be known as the greenhouse effect.

—1896: Swedish chemist Svante Arrhenius predicts increased levels of carbon dioxide in the air due to burning of fossil fuels by humans will cause a slow increase in Earth’s temperature.

—1938: British engineer Guy Callendar publishes one of the first studies demonstrating how the burning of fossil fuels is raising the Earth’s surface temperature. His work is largely ignored. Read the full story