Why population growth is a public health concern?

In most contemporary models of the earth there is only a finite amount of resources so as populations rise the amount or resources available to each individual shrinks. Studies show us that this informations is not really accurate since less than 2% of the entire human population control use and access to 90% of all material resources on the planet. This unequal distribution makes it nearly impossible to know how many people the earths resources are actual capable of maintaining since most people are denied free access to resources due to laws and regulations that are created my people who already have access to resources and thus  can deny access to other. In many ways the concepts of ownership and profit prevent fair distribution of resources. 

Pretty bad i would assume.