Even though currently the world is at it's most technologically advanced stage, we still have problems to worry about. At this time in modern history, the human economy and population faces a big problem. Sustainable growth has become an issue because of the ever-growing human population.
To add to that, in the future, certain cities and areas might not be able to support so many people. And this could lead to health issues and other problems. Countries that aren't fully economically stable are a special concern, since they probably won't have enough resources for everyone.
Yes, the population is growing at an extremely fast rate. By 2050, the human population is expected to be about 9.8 million.
Yes, and at this time, scientists are working to maintain food supplies and other necessary things equal with the rate of human growth.