It's only been 12 years since we passed 6 billion, in 1999. In contrast, the world population growth from 1 billion to 2 billion took 120 years.
What's next?Our human population is expected to hit 9.3 billion in 2050. Some scientists project human population growth to begin leveling off between 9 and 10 billion. Others predict continued geometric growth well beyond 10 billion.
Caption: world population growth between the years 1800 to 2100
Growth is due to reduced death ratesThe growth is due to reduced death rates rather than increased birth rates. The decreased death rate is attributed to the distribution of effective vaccines and antibiotics, as well as improvements in public health conditions. These recent medical advances have improved life expectancy most dramatically in developing countries, where most of the population growth is happening.
As the poorest populations expand, scientists say unrest will growBy 2050, the population of India will surpass that of China. Nine of the most populous countries at that time will be developing nations where poverty is widespread. Issues of unequal distribution of world resources will loom larger; borders of industrialized and wealthy countries will grow increasingly porous.
U.S. will be only developed country among the most populousIn 2050, the U.S. will be the only industrialized nation among the 10 most populous countries. Our over-consumption of the world's resources will be even more out of proportion to the rest of the world than it is now.
Oil has fueled this growthAlthough medical advancements have played a role in reducing death rates, it's been the abundance of oil that's allowed populations to grow so large. With cheap oil it's been possible to power the machinery to build large cities and support them. Take it away and you can't sustain New York, Tokyo, Delhi, Mexico City, etc. All cities, even those of moderate size, will suffer dramatically when we run out of oil, which many scientists predict within 50 years (see http://www.worldometers.info/).
Keywords: population growth 7 billion oil end of oil