Dear James, dear people
Whether we can save the world depends on the point of view and on what we do in our daily life. (More people does not automatically mean that better ideas will come through.)
The longer the run, the more contraproductive is egoism, it leads to destruction and wars.
So let us see the whole picture, let us help each other and try to safe the planet, which reversely will help our children and humankind - and thus ourselves.
Freedom and tolerance are better than suppression. Laws should play a model role, this is one reason why I am completely against death penalty, no matter what.
Individuals shall have a chance to change and become better persons.
Everyone is able to steer the world a bit, even if we go shopping. Less is sometimes more. Be critical but constructive.
Astronomy and space habitats are very interesting and - under certain circumstances - we might have the right to settle in space - but on the other hand, our priority should be to save planet Earth, not only to save our own species. Biodiversity is precious (even for our own benefit too).
Some fields of knowledge can be exponentially increased to a certain degree and for a certain time but most real singularities of knowledge and technology with infinite potential are probably only a pious dream and even quantum computers and artificial intelligence will not do the whole job, because it takes human resources to convert results into benefit.
Unprecedented physics experiments as particle collider experiments (and a few others) could bear the risk of a typical man-made mousetrap-level steering problem, because it would be too late to steer when a catastrophe occured and no more learning effect could take place after the destruction of Earth.
This is quite seldom in nature, as without feedback there would be no evolution.
Other risks with still grave consequences are much more difficult to avoid, as for example different catastrophic effects of planetary overpopulation.
Will enough people understand the relation between probability and worst case and will we be able to develop and apply the necessary standards to avoid such risks?
Let us expect the worst but do our best whenever we can, before it is too late.
All the best