Why are many scientists concerned about population growth? they're afraid the unemployment rate will increase. they're worried about running out of land to build houses on. they're not; they think it's a good thing. they think it could lead to a lack of natural resources in the future.

The last option is the correct answer. Scientists are concerned about population growth because the planet's resources are finite. The more people, the greater the difficulty to make an efficient use of resources, and thus, the harder life gets. Thomas Malthus, English scholar, says: "The power of population is indefinitely greater than the power in the earth to produce subsistence for man" and the biologist Paul Ehrlich states "We have a finite planet with finite resources. In such a system, you cannot have infinite population growth". It is, without a doubt, a problem that should be more present in the individuals' lives.