THE HUMAN POPULATION STABILIZING WORLD POPULATION HUMAN POPULATION

THE HUMAN POPULATION STABILIZING WORLD POPULATION

HUMAN POPULATION GROWTH Like other populations, size of human population tends to increase with time Long ago, human population was limited by food, disease, & survival to adulthood rates were low ~500 years ago, human population began growing rapidly w/ agriculture & industry making resources readily available, improved sanitation, medicine & health care Human Population

HUMAN POPULATION GROWTH What type of growth is this showing? Can this go on forever? Why or Why not? Human Population

Human Population

HUMAN POPULATION GROWTH Current World Population? 7. 14 billion Current U. S. Population? 317. 4 million source: U. S. Census Bureau 1/20/2014 2005 Transitions: Prior to 2000, young outnumbered old Until ~2007, rural outnumbered urban From 2003, replacement rate stalls: median woman has too few or just enough children to replace herself & the father in the next generation (Cohen, 2005) Human Population

HUMAN POPULATION DISTRIBUTION Human Population

HUMAN POPULATION GROWTH doubling of population once estimated to occur every 37 years folks who died <1930 never saw a doubling folks born >2050 projected to not observe population more than doubled for folks >52 today: 3 billion in 1960; 7 billion in 2011 (Cohen, 2005) age distributions, fertility, developed vs. developing nations … implications for future? Human Population

Advances in Global Health Result in a Decrease in (d) Greater food production Better and more accessible medical care Improved water quality Improved sanitation Human Population

HUMAN POPULATION GROWTH human population cannot grow exponentially forever, b/c resources limited In 1800 s, Malthus predicted war, famine & disease would limit human population growth Today, scientists study human population including birthrates, death rates, & age structure to predict growth rates = demography Human Population

HUMAN POPULATION GROWTH demographic transition changes in fertility, mortality, makeup epidemiologic transition shift in morbidity/mortality patterns from infectious/ communicable to chronic/ degenerative diseases consequences of population increases urbanization & the environment Human Population

HUMAN POPULATION DEMOGRAPHIC TRANSITIONS Demographers developed hypothesis to explain slowing of population growth using changing in birth & death rates = demographic transition Initially, birthrate & death rate equally high advances decrease death rate, while birth rate remains high (births > deaths �pop increase) modernization decreases birthrate �population growth slows eventually, birthrate & death rates are equally low & population growth stops Human Population

HUMAN POPULATION: DEMOGRAPHIC TRANSITIONS Human Population

HUMAN POPULATION: IMPACT DEBATE Many ecologists suggest that if human population growth doesn’t slow down, there could be serious and lasting damage to the environment and global economy Other scientists believe that science, technology, and positive changes in society will help control negative impacts of humans Human Population

Human Population