- Demographics
- Human revolutions
- Planetary boundaries


[SLIDE 1]

Demography is the field of collecting, compiling and presenting information about human populations.

Terms used in demography include:
- growth rate or the rate of growth of a population
- total fertility rate (the average number of children a woman has over her lifetime)
- replacement-level fertility (the fertility rate to replace a woman and her partner)
- infant mortality (the number of infant deaths per 1,000 live births)
- population profile (the bar graph showing numbers of males and females for successive ages in the population)
- population momentum (the effect of current age structure on future population growth)
- crude birthrate (the number of live births per 1,000 in the population in a given year)
- crude death rate (the number of deaths per 1,000 in the population in a given year)
- epidemiologic transition (the shift from high death rates to low death rates in a population)
- fertility transition (the decline of birth rates from high levels to low levels in a population)
- demographic transition (the tendency of a population to shift from high birth and death rates to low birth and death rates)


[SLIDE 2]

Human beings have changed dramatically over the years in every aspect. There has been steady growth in every part of human life, often led by organized groups and new inventions or methods. The first known revolution is the Neolithic Revolution that happened 40,000 years ago. Human beings foraged for food and came together in groups to hunt and find food. About 12,000 years ago, the next major change happened with the  Agricultural Revolution where human beings actively cultivated food. There was a division of labor and the growth of cities occurred. By the 17th century, two revolutions occurred - Industrial and Medical. The Industrial Revolution brought mechanization with tools and the birth of industries and mass production. It also began the heavy use of fossil fuels to supply energy for growing needs. The medical revolution brought vaccinations, water treatment and better nutrition. Prior to these medical breakthroughs, many human beings died of simple diseases and most people combated life on a daily basis as a simple flu could be deadly. After World War II, the Green Revolution occurred where farmers had access to better farming tools and methods. Both irrigation and fertilizer use increased crop yields dramatically.

Today, we are in the midst of an Environmental Revolution where we are learning how to use green technologies using faster computers and artificial intelligence to increase productivity, while taking care of our planet and our limited natural resources.


[SLIDE 3]

Human population is constantly growing. In prior centuries, natural disasters, disease and other factors limited population growth. It took until 1830 for the human population to reach 1 billion worldwide. Today however the population is growing so fast that it passed 7 billon by 2011. The UN estimates that world populations will surpass 8 billion in the next decade or less and be at 9 billion in 2045.

The Earth has finite natural resources that cannot sustain such large populations at any healthy level. In 2009, a team of 28 academic researchers led by Johan Rockstrom at the Stockholm Environmental Institute suggested a set of planetary boundaries for a safe operating space for humanity.

The scientists proposed a series of limits or tipping points that, if passed, would keep humanity from surviving.