The continuous increase of major urban centers in the world presents several challenges for their populations and the world's environment. Specifically, aerosol-related hazards such as sand and dust storms, wildfires, and urban pollution all affect megacities and are tied to the growth of cities as well. In this chapter, we examine natural and anthropogenic aerosol-related hazards affecting the world's megacities. We concentrate on three geographic areas, Egypt, China, and the Indo–Gangetic Basin, all of which contain large population centers and face acute environmental issues. We examine with specific examples the great potential of remote sensing technology to track, model, and analyze such hazards for the benefit of all concerned.

Introduction

The world's population has more than tripled in the past 70 years. Between 1830 and 1930, the world's population doubled from 1 to 2 billion people. By 1970, it had nearly doubled again, and by the year 2000, there were about 6 billion people on Earth. This rapid increase in population is sometimes called the population explosion because the exponential growth of the human population results in an explosive increase in numbers, illustrated in Figure 10.1. The continuous increase in world population is expected to reach 9 billion by the year 2050 (Figure 10.2).