Apocalypitic Stories

the world has been destroyed by global warming and nuclear war, in France a group of scientists have the task of trying to make plants grow again so that food supplies don't run out. earth is almost inhabitable as the air is toxic and the temperatures are below minus 50 degrees. Is this the last hope for humanity or can they turn things around? hi, this is a story that I wrote for English and I am deciding to continue writing. can I get some feedback or ideas on how the plot should carry out?

It was a perfectly normal morning on Saint Bridget's street. Or so they thought. Today was the day that 14 year old Kim would be made to make a decision. To stay with her family and their profession or to leave the country to seek a new adventure. After the World War III, everywhere was ruined to shreds except for the place which was formerly known as Europe. To live they must leave their family's to provide for the world using their job. Each country has their own profession but it is up to the 14 year olds to decide what to do. What will Kim pick? And who will she fall in love with?