Some reasons for sustaining our biosphere

It has been estimated that our sun is in its half-life and has another five billion years before it uses all of its hydrogen gas. It will eventually expand its size so great that surrounded planets including the earth would be engulfed. Between now and the point in time when that event comes, we must learn to sustain the biosphere to the upper limit and hope that space travel to distant stars would be available before that time. For the moment it is crucial to convince the public to sustain the environment in every way they can, for it is the only place we have to live now. The environmental crisis as we all know lies in the actions that we, the 21st century people, take to preserve and sustain our biosphere.