Why would an environmental group work to discourage people from moving to florida? to prevent problems related to urban sprawl to prevent crowded schools and classrooms to prevent a redrawing of congressional districts to prevent a rise in the cost of government services

Many environmental groups have worked hard to try to prevent the problems that the city of Florida has related to urban expansion on ecological areas, natural systems, water sources and protection of species habitats. So the first option is the one that is based on more cases. In addition, the problems of school overcrowding, congressional districts or increased government services are not appropriate topics for environmental group discussion. They are more political issues. Only the first issue is a cause of permanent conflict with many environmental issues.

An environmental group would try discourage people from moving to Florida to prevent problems related to urban sprawl.

An environmental group or movement seeks to protect or monitor the environment against misuse or degradation from human forces.

Florida is the third densely state in the USA ( after California and Texas ). In order to accommodate the increasing population new houses have to be built and new infrastructure established. This is done at the cost of the environment ( clearing land, river beds and beaches for building sites), and the animals living there ( forcing them out of their usual habitats ). The water availability and air pollution are huge problems as well ( more people = more cars=more pollution ). If the population  rises constantly there won't be enough space in Florida for all these people. Urban sprawl destroys the environment by creating artificial and heavily polluting living areas where once the nature was untouched.