The rapidly increasing population has many effects on the ecology of the planet. One of the main effects is the food supply. More people will obviously require more food, thus putting a strain on the planet as we try to grow an ever increasing amount of food. This accelerates soil depletion (loss of beneficial nutrients from the soil) and stresses water supplies due to increased irrigation. Another major effect of population growth is the harvesting of raw materials. More people are going to need and want more manufactured goods, particularly if they increase their general standard of living over time. This will require more raw materials to be harvested from the planet (metals, minerals, fossil fuels, etc.) which in turn will have an increasingly negative impact on the planet. Finally, the waste products (trash) from all of these people will continue to increase in size and will be difficult to adequately dispose of. As you can see, we will need to find more efficient and less destructive ways to live as the population of the planet increases.