Building a whole world

Yesterday I finally got back to writing Panthera : Death Plain after a week of distractions.  Although this book is set on Earth, the world I'm writing about has changed, and although I'm using familiar reference points things are different.

Earth is already overpopulated, and I've assumed that it will continue to be so even when humans  spread out over a vast amount of space.  Earth will always be the home world of humans, and there'll be many millions of us who won't leave home even when space travel is safe and relatively easy,

But I wanted to reflect some of the current environmental debates in my picture of the planet.  So I have a massive re-greening project going on at the southern edge of the desert.  These schemes are getting under way now, but I wanted to make this bigger than anything we're currently doing.

Because I have a passion for big cats I wanted to create a world in which they still have space to exist. So I have several reserves on the continent of New Africa.  But I also expected that the same issues will dog conservation as today - pressure on land for human development, poaching, ranchers killing cats who take cattle.

I've built my world in each of the three Panthera books around the story I wanted to tell.  I wanted the habitats on each world to show off the qualities of the big cats I was writing about.  But you might equally start from the other end, with a world hostile to human life and see how your characters deal with that.  World-building that way could take your characters mining gas giants, exploring ice worlds for incredibly rare and valuable metals or minerals, or terraforming a barren planet to suit their needs.  How you build your world will be shaped by the story you want to tell, but there's still scope for dazzling invention in the details.  Think Avatar and Pandora.