Theoretically, humans, if they were good, could create a world that would last quite a while before the sun destroys the planet. However, humans aren't good. If I didn't believe in the Christian Gospel, I wouldn't have much hope for the world.
Discussion
Earthlings have an appointment with Sol’s fury in 1 billion years.
If the descendants of humanity are to escape that fate, how big of a window do people feel we have before humans lose dominion over the means to escape?