What is the nearest planet suitable for human habitation?

Let me say something. At present, no planets suitable for human habitation have been found in the solar system, but some planets will be naturally suitable for human habitation after modification or in the next few hundred million years. Human habitation should at least have a basic living environment, such as water, oxygen and temperature. At present, it is closest to Mars, but Mars has no atmosphere, so the temperature is low. At present, we are looking for water. After years of scientific research, it has been proved that there was water on Mars, and water may exist in underground fires in the form of ice. There are plenty of carbon dioxide dry ice in Antarctica and the Arctic. As long as the temperature rise will cause the greenhouse effect and make Mars form an atmosphere, it may be suitable for human habitation. Titan is closer to the earth than Mars, but it's too cold there. The environment of other planets is quite bad and uninhabitable.