Shock can be tricky; it is all too easy to put people off if it feels needy or overstated. Al Gore did shock quite well in Inconvenient Truth.

But we need to get people's attention, and shock can do that. In my experience many potential readers of this kind of stuff really don't quite get the science, so you have to visualize the problem and the solution, if possible in a simple insight.

An example is the 'we can't exploit the resources of more than 1 planet' insight. That is a very simple way of talking about sustainability. Once you have established that thought in people's minds, it is easier to introduce more complex ideas that relate to it.

You can't be me, I'm taken