Terraforming of Mars is a hypothetical process of planetary engineering by which the surface and climate of Mars would be deliberately changed to make large areas of the environment hospitable to humans, thus making the colonization of Mars safer and sustainable.
There are a few proposed terraforming concepts, some of which present prohibitive economic and natural resource costs.
[1] As of 2018 it is not feasible, using existing technology, to carry out any activities that significantly increase the atmospheric carbon dioxide (CO
2) pressure[clarification needed] or provide any significant warming of the planet. Any climate change induced in the near term is likely to be driven by greenhouse warming produced by an increase in atmospheric CO2 and a consequent increase in atmospheric water vapor. These two gases are the only likely sources of greenhouse warming that are available in large quantities in Mars.