Yellow line: solar radiation: when it gets to the atmosphere, it can be reflected, it can be absorbed by the atmosphere, or it passes through the atmosphere to the earth"s surface, most of it is absorbed. Large of it bounces off the atmosphere and warms the earth up. Greenhouse gases: atmospheric gases that absorb infrared radiation ( radiatively active gases ) The greenhouse effect is normal and has been occurring for centuries: the anthropogenic, or human-generated, contributions to the greenhouse effect is what we are concerned about today. The relative ability of one molecule of a given greenhouse gas to contribute to warming: expressed in relation to carbon dioxide (potential = 1) The effect of any given greenhouse house reflects: Its global warming potential: property of particular molecules. Its abundance in the atmosphere: how its abundance is changing over time, when we think about what greenhouse gas are more important, it is not necessarily the highest global warming potential.