Climate change.

What is climate change/global warming?

How are the greenhouse effect and climate change/global warming linked?

What is the runaway greenhouse effect, where does it occur, and could it be an issue for the Earth?

1. The climate, or global warming is basically the process of changes in the climate on Earth. The climate has constantly been changing throughout the past of our planet, and it continues to do so. There have been periods of cooling, and periods of warming, often causing dramatic changes on the planet.

The current climate change has caused lot of panic and attention, with the main reason being that the human activity has been having influence on it. While this is true, the human influence has often been exaggerated, as it is still only a small fraction of what the nature manages to do. That doesn't mean though that precaution measures don't need to be taken, on the contrary, something has to be done so that the human activity doesn't become too big of a factor in it.

2. The greenhouse effect is a natural effect caused by the gasses in Earth's atmosphere. The gasses like carbon dioxide and methane have the property to trap the heat into the Earth's atmosphere, and as they do, they manage to increase the global temperatures. The more of these gasses there are in the atmosphere, the warmer it gets, so the end result is a warm and wet planet, kind of like a greenhouse.

The global warming is directly caused by the greenhouse gasses. As mentioned, when the concentrations of these gasses in the atmosphere rise, there is more heat trapped in the atmosphere. The more heat there is in the atmosphere, the more heat the surface of Earth will experience, with the temperatures being on the rise all over the planet.

3. The runaway greenhouse effect is a situation where the atmosphere is so saturated with greenhouse gasses that it is no longer able to radiate heat out of it and into space. That causes constant warming up of the planet and drying out of all the water bodies, making it a dry planet.

This process would happen in the atmosphere, more specifically in the second layer, the stratosphere, where the accumulation of the greenhouses will happen. Also, the water vapor will be going up to this layer and managing to escape the atmosphere through hydrodynamic escape.

The Earth doesn't seem to be anywhere near a situation like this, and it hadn't come in such a situation even when the greenhouse gasses concentration was much higher than what it is nowadays. If something like that happens though, than the Earth and every living organism on it will be in huge trouble. The temperatures will rise so much that most organisms will not be able to sustain them. On top of it, the water will be escaping the planet, and eventually there will be none left, so the living organisms will be left without the basic thing that enables life. This scenario will cause the biggest mass extinction on Earth, and very likely put end to the life on it.