evidence: With CO2 and other greenhouse gases, it’s different. Carbon dioxide, for example, absorbs energy at a variety of wavelengths between 2,000 and 15,000 nanometers — a range that overlaps with that of infrared energy. As CO2 soaks up this infrared energy, it vibrates and re-emits the infrared energy back in all directions. About half of that energy goes out into space, and about half of it returns to Earth as heat, contributing to the ‘greenhouse effect.’ [...] Before humans began burning fossil fuels, naturally occurring greenhouse gases helped to make Earth’s climate habitable. Without them, the planet’s average temperature would be below freezing. So we know that even very low, natural levels of carbon dioxide and other greenhouse gases can make a huge difference in Earth’s climate. [...] In the case of greenhouse gases, the planet’s temperature is a balance between how much energy comes in versus how much energy goes out. Ultimately, any increase in the amount of heat-trapping means that the Earth’s surface gets hotter. (For a more advanced discussion of the thermodynamics involved, check out this NASA page.)