If we develop the technology to live on Mars, then we may be more ready to deal with Earth getting messed up. Otherwise, the deterioration of Earth might happen

If we develop the technology to live on Mars, then we may be more ready to deal with Earth getting messed up. Otherwise, the deterioration of Earth might happen too suddenly for us to develop technology to deal with. (We could develop the technology without going to Mars, but it might be harder to fund tech for "what if Earth's atmosphere becomes unbreathable" to completion long before that's an issue.)