But scientists are nothing if not resourceful. Below is a measurement in the amount of infrared energy reflected (more technically, absorbed and re-emitted) back from the atmosphere to earth — the “Greenhouse Effect”. This measurement isolates wavelengths where CO2 is the sole contributor of the reflection. And lo, the amount of reflected energy not only tracks the long-term trend in CO2, but it also tracks the seasons, as atmospheric CO2 decreases in the spring as plants grow, and increases in the fall when they go dormant. It clearly shows a dose-response relationship.