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Why "Greenhouse" Effect is Wrong Well, the Greenhouse effect isn't really wrong, it's the name "Greenhouse" that's the problem. Because the analogy of how our atmosphere warms has nothing to do with how a greenhouse warms!
The greenhouse warms because it is surrounded by a glass enclosure. This allows sunlight energy to enter the greenhouse, and then heat the plants and ground which then emit heat into the air. Here's the key, the glass enclosure prevents this heated air from mixing with the cooler air outside the glass confines. Specifically, it limits the convection of air. If the word "convection" is confusing, it's basically a term to describe how heat energy circulates. In meteorology it refers to how warm air flows upward and cool air sinks to the surface. So warm air in a greenhouse rises to the ceiling and stops. Some of the heat energy in the air is absorbed by the glass which then emits some heat energy back down towards the plants. As more sunlight energy enters, very little energy "escapes" the confines of the glass enclosure and thus the air gets warmer and warmer. That's how a greenhouse warms. But in the atmosphere there is no glass enclosure!
What happens in the atmosphere: Sunlight energy (short-wave) passes through the air to earth, most of it not being absorbed by the atmosphere. This is because most of the gases in our atmosphere absorb heat energy in a different form called long-wave. It just so happens that the earth, both land and oceans, absorb the sunlight energy and also emit long-wave energy. So, the long-wave heat energy being emitted by the earth back into the air is absorbed by "greenhouse" gases like water vapor, carbon dioxide, methane and others. As these gases warm, they release more of their own heat energy back to earth. So, the surface of earth receives heat energy both directly from the sun and from the greenhouse gases radiating heat back to the surface. In fact, the surface gets more heat radiation from gases in our atmosphere than from the sun! Yeah, pretty cool to think that the reason our planet is even warm enough for life is not because of the sun directly, but because of just the right amount of water vapor, carbon dioxide and other "greenhouse" gases in our atmosphere. But in a greenhouse, this process is happening too. So far, there's not much difference between the atmosphere and the greenhouse. The key is that the atmosphere has no glass enclosure that prevents convection. If the earth's atmosphere had no convection, the global mean surface temperature would be 85°F(1). But then why is the actual global mean temperature 60°? Convection of course. As warm air near the surface rises, it cools (called adiabatic cooling). This makes for warm air near the surface and cooler air aloft. Because cool air is denser than warm air, the cool air will sink and the warm air will rise, thus driving convection in our atmosphere. Because the sun heats the surface and because as warm air rise it cools aloft, there is a replenishing of warm air near the surface and cool air aloft. This makes for a regular cycle of warm air rising and cool air sinking. This type of convection is limited in a greenhouse and that's why "greenhouse" effect is a bad name.
A Picture of the less controversial Green House!
(1) http://bostonreview.net/BR32.1/emanuel.html
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What happens in a greenhouse: