According to UN data (https://population.un.org/wup/DataQuery/), the world population will reach 9.7 billion (9.7 × 109) by the end of 2050. It's presumed that almost 70% of that population will be an urban population with many cities having over 10 million inhabitants. It's a significant number and, as the number grows, not only are we presented with new opportunities, but we also face many unique challenges:
The most difficult challenge is making resources and energy available to all of the inhabitants and, at the same time, avoiding environment deterioration. At present, cities consume 75% of the world's resources and energy and generate 80% of greenhouse gases; while there's a trend towards green energy sources, we all understand that the earth's resources, such as food...
