This is New Delhi, India, population 22 million. The city has a population density of 30,000 people per square mile.

India is the world’s most populous democratic country with a population of 1.4 billion inhabitants and according to the World Health Organization Delhi is the fourth most polluted city in the world in terms of suspended particulate matter. The growing pollution is responsible for increasing health problems, and the deteriorating environment is the result of population pressure and haphazard growth.

There are now more than 7,800,000,000 people on planet Earth.

It took until the early 1800s for the world population to reach one billion. Now we add a billion every 12-15 years.

Population is a dynamic field. There have been significant changes in birth rates and the population trajectories of countries and continents in recent years. Global population is still growing by more than 80 million a year, however, and is most likely to continue growing for the rest of this century unless we take action.

Photo courtesy of Global Population Speak Out. PopulationSpeakOut.org