When CO2 absorbs longwave radiation, is that analogous to a microwave oven heating water molecules?

Question

Since CO2 absorbs radiation in the infrared spectrum, is this the same principle that microwave ovens use? The microwaves vibrates the water molecules, causing them to heat up.
I'm just trying to find a way to explain how the greenhouse effect works.

Answer 1

You're on the right lines. The important difference between incoming solar radiation and outgoing thermal radiation is that thermal radiation has a longer wavelength.

It's not so much that the radiation is absorbed by CO2 and the other greenhouse gases, more that the longer wavelength radiation has difficulty escaping from our atmosphere. The passage of shorter wavelength solar radiation through the atmosphere isn't impeded by the molecules of greenhouse gases unlike the progress of thermal radiation.

Answer 2

Microwaves excite rotational modes of water molecules, not vibrational bands. The rotationally excited water molecules then start spinning into each other and translate the rotational energy into vibration and motion so the temperature rises. Climate forcing by CO2 involves exciting vibrational bands of CO2, not rotational.

Aside from that what you have described is similar, CO2 absorbs outgoing infrared radiation in a few specific bands, this heats up the troposphere a little, and then the troposphere re-radiates some of this excess heat back to the surface. This process is known as climate forcing and given in units of a power flux, watts per meter sqaured.

If you google "climate forcing" you can get more long-winded explanations of the above.

Answer 3

The idea is light loses energy when it passes through the atmosphere, or any other transparent medium (glass, clear plastic) .

That shifts it toward the red (heat) end of the spectrum. Because it's lost some of it's energy it doesn't have enough to pass back out through the atmosphere if it gets reflected back, so it stays within and adds to the warmth of the planet. It's exactly what happens within a glass greenhouse, or a car in bright sunlight.

Answer 4

No:
It is more like your glasses absorbing the ultraviolet light. A specific molecular resonance.

Water is the great energy absorber of all kinds of energy. You can shoot a bullet into water it will bring it to a halt and dissipate the heat that results also. Water absorbs all kind of energy. Electrical, heat, all electro magnetic radiation including light of all spectrums, and motion.

Answer 5

Not like a microwave, more like an easy-bake oven you played with as a kid.

The light bulb inside is like the sun. And now it's like someone put a 75watt bulb in place of the standard 60 watt bulb.

Just like the sun is hotter today, the 75 watt bulb is warmer than the 60 watt bulb, and things cook faster.