“There is no question that climate change is happening; the only arguable point is what part humans are playing in it.” –David Attenborough If the Earth didn't have any global warming at all, our planet's mean temperature would be 255 K, or about -1º Fahrenheit: the mean temperature of the Antarctic continent. As it stands instead, our planet is much warmer than that, owing to the warming, insulating effects of the atmosphere, which is largely transparent to (incoming) visible light, but traps a fair amount of the (outgoing) infrared radiation.