"God may exist, but science can explain the universe without the need for a Creator."
Science can "measure" & come up with a "theory" of what it "measures". As for an explanation of this "theory", & if it is "accepted", as being "valid", I "hope" is a better way to explain.
"The scientific account is complete, theology is unnecessary."
As long as there's money in that account, that account is "complete". Theology offers something that doesn't require funding, but does encourage work to achieve money.
"We are in danger of destroying ourselves by our greed and stupidity. We cannot keep looking inward at ourselves on this small and increasingly polluted and overcrowded."
Self restraint requires looking inward, greed is a bi-product of this inability to look inward. The world is growing increasingly nationalistic & territorial, so imperialism will require genocide. This itself is inhumane, something that happens when we loose faith & Humanity.
"If we can get through the next few hundred years, we should have spread out into space. Then, an isolated disaster will not wipe out the entire human race."
It won't matter what happens in the next few hundred years, that's not our concern, nor the concern of our children, but maybe their children's, children's, children.