Forty years of ice-core records of CO 2

In 1980, a method was found to determine the amount of carbon dioxide in ancient air trapped in polar ice — providing direct evidence that CO2 is coupled to climate, and affects global temperatures in the past, present and future. In 1980, a method was found to determine the amount of carbon dioxide in ancient air trapped in polar ice — providing direct evidence that CO2 is coupled to climate, and affects global temperatures in the past, present and future.