Given the task definition and input, reply with output. You are given a passage. You need to construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) its answer is the whole paragraph. Avoid creating questions that can be answered correctly without actually understanding the paragraph.

Global warming has two main applications. The first is that there are certain gases that trap heat in the atmosphere, warming planets. This is known to take place on Venus, Earth, and the gas giants. Earth is the hospitable place that it is because of global warming.\n\nThis takes place because of greenhouse gases, which allow radiation from the sun to pass through the atmosphere and warm the surface of the earth. The surface then re-radiates this energy back towards space in the infrared spectrum. This energy would escape and our planet would be as cold as the moon, were it not for the greenhouse gases (mainly CO2, ozone, methane, and water vapor). They absorb the infrared energy and radiate it back to earth, increasing the overall amount of radiation hitting the earth's surface, keeping it warm day and night.\n\nThat this takes place is clear and indisputable. There is simply too little energy coming from the sun to account for our planet's temperature. The controversial point is when global warming is applied to the current rise in average global temperature that has taken place over the past 50 so years. Most scientists believe that warming of the planet is due to increases in greenhouse gases, mainly CO2, mainly due to human activities on earth.

what is the concept of global warming?