The time has come when we cannot be so careless. Unless we do better, we may suffer through a stark emergency of the environment. We may create a hostile world: a world to bruise ourselves against; a world of sprawling cities, unplanned or badly planned; a world whose water is full of sludge, whose winds are full of soot; a world whose landscape has been totally neglected, stripped, marred, and wasted. All of this need not happen if we choose well, and particularly if we plan well and if we act well.