The environment is the fundamental antagonist in Forgive Us, the first book in the Odemark Series. The earth is toxic, and the very air itself is a corrosive poison. All resources are limited or non-existent. The discovery of green grass and clean water is astounding.
This grim situation (caused by the pollution from Ignium, a new energy source) is the very reason that Arcardia, the space station in the third timeline, even exists. Thus, pollution is the major cause of the actions related to survival.