As the earth is constantly heated by the sun and we have the law of conservation of energy. Why is the Earth not constantly warming up?


So we have long-term Ice-Ages, but also relatively short term ([](

When the temperature is going down (on average), where does the energy go?


PS. I am fully convinced we have climate change, we are the problem, etc. I only care about the ‘scientific’ answer.

In: Earth Science

The planets emit heat energy out into space. The vacuum of space prevents conduction or convection, how we normally cool ourselves on earth.

Heat loss is through the portion of the electro-magnetic spectrum we call heat/infrared.

we also radiate energy (heat) outwards into space, so only if the difference between energy absorbed and energy emitted is positive we heat up, that’s why the gases in our atmosphere are so important

About 30% is directly reflected back into space. Another 25% is absorbed by the atmosphere with some of that being re-radiated back into space. A lot of heat goes into evaporating water from the oceans. During Ice Ages more heat is reflected due to high albedo of the ice (kind of a self-reinforcing loop).

The sunlight warms up the earth, earth radiates its warmth in infra red, it is also a kind of light, but not visible to you. Luckily our atmosphere is transparant for both visible and some invisible kinds of “light”.. UV for example (on the other end of the spectrum) is mostly blocked, but infrared can and will escape, so our earth radiates its warmth into space.

Now, CO2, methane and other nasty gasses are not transparent for infrared, it reflects it. That is, in a nutshell, the greenhouse effect.

The Earth is basically a giant light bulb, emitting light (technically “electromagnetic radiation”) into space. This uses energy.

You may not think of the Earth as emitting light. All objects do, but the color (technically “frequency”) of the light depends on the temperature of the object. In general we can only see colors emitted by objects that are hotter than we are (e.g. the Sun), since there’d be no point in being able to see the light emitted by our own eyeballs.

(This is how “heat”-seeking missiles and some types of night-vision goggles work. They don’t actually detect heat; they detect the *light* emitted by objects that are hotter than their surroundings.)