Human Population Growth

The Carrying Capacity of Earth?

The carrying capacity of Earth is not known and at present it is impossible to determine when the human population will stop growing

DemographyDemography The study of human The study of human

population growth trendspopulation growth trends Looking at past trends helps Looking at past trends helps

in determining future trendsin determining future trends Demographers study the birth Demographers study the birth

rates & death rates (rates & death rates (which which determines growthdetermines growth), fertility ), fertility ((factor of birth ratefactor of birth rate), and age ), and age structures of populationstructures of population

Human Pop Growth

• Tends to increase, just like other organisms – however – the rate of increase has changed dramatically

Growth over the last 2000 years…

• http://www.globalchange.umich.edu/globalchange2/current/lectures/human_pop/human_pop.html

By the numbers…• World Population Growth• Year 1 200 million • 1000 275 million • 1500 450 million • 1650 500 million • 1750 700 million

• 1804 1 billion • 1850 1.2 billion • 1900 1.6 billion

• 1927 2 billion • 1950 2.55 billion

• 1955 2.8 billion

• 1960 3 billion • 1965 3.3 billion• 1970 3.7 billion • 1975 4 billion • 1980 4.5 billion • 1985 4.85 billion • 1990 5.3 billion • 1995 5.7 billion

• 1999 6 billion • 2006 6.5 billion • 2009 6.8 billion • 2012 7 billion • 2027 8 billion • 2044 9 billion • 2050 9.2 billion

Largest Countries in the World

China - 1,330,044,544 India - 1,147,995,904 United States - 303,824,640 Indonesia - 237,512,352 Brazil - 196,342,592 Pakistan - 172,800,048 Bangladesh - 153,546,896 Nigeria - 146,255,312 Russia - 140,702,096 Japan - 127,288,416

India - 1,628,000,000China - 1,437,000,000 United States - 420,000,000Nigeria - 299,000,000Pakistan - 295,000,000Indonesia - 285,000,000Brazil - 260,000,000Bangladesh - 231,000,000Democratic Republic of

Congo - 183,000,000Ethiopia - 145,000,000

2008 2050

Predictions of Future Population Growth

• Predicting how a population’s size may change…–Begins with determining information about individuals in each of the population’s age classes

–Creating an age-structure graph…

Demographic Transition

• A dramatic change from high birth rates and high death rates to low birth rates and low death rates (slowly growing)

• The US, Europe, and Japan have completed this demographic transition

• Parts of South America, Asia, and Africa are in stage 2 of 3, where death rate is down but birth rate is still high

Interesting Tidbits..• The Ecological Footprint data suggest that 3 – 4

planets with the Earth’s bioproductive capacity would be required to support the current population at the consumption level of North Americans

• The ten countries which will contribute most to world population growth over the next 30 years are India, China, Pakistan, Nigeria, Ethiopia, Indonesia, United States of America, Bangladesh, Zaire, and Iran

• 171,000 517,000 density 1950-2050