The scientists behind the Paris accord use data (a span since the Industrial Revolution) that is too brief to be helpful. Much longer data is required to get a sense of earth's fluctuating climate. So why did the Paris accord, alongside American politicians, use shorter data? What percentage of the earth's history has been ice age? Is CO2 dangerous or beneficial for plant life? Is it—I know it sounds crazy—but is it possible the carbon dioxide we pump into the atmosphere is beneficial for life on earth? What is going on?