Hope and despair? how was it developed in the film?

Alfonso Cuarón, the director, paints a grim vision of the near future. His cinematography is very grey. There is a sense of hopelessness. The world is imploding because people simply do not care for a world without children. People simply just get old and die. Schools and playgrounds are rotting. A sense of futility for the future takes over. The only hope lies in Kee (Clare-Hope Ashitey) who is the only woman in the world who is pregnant. As the world unravels it is Kee and her baby that hold the "key" to the future of mankind.