human&population,& environment… · human&population,&...

HUMAN POPULATION, ENVIRONMENT AND MIGRATION

Human popula9on growth: 6 billion •  Popula9ons con9nue to rise in most countries

–  Par9cularly in poverty-‐stricken developing na9ons •  Although the rate of growth is slowing, we are s9ll

increasing in absolute numbers

Humans are Recent Arrivals

•  Earth -‐ 5 Billion Years

•  Mul9-‐cell Biota -‐ 600 Million Years

•  Human Beings ~ 2 Million Years

•  Human Popula9on Growth into Billions -‐ Last 200 years

A Million Years Of Human Growth (1)

6 Billion6 Billion

The human popula9on is s9ll growing rapidly

•  It took all of human history to reach 1 billion •  In 1930, 130 years later, we reached 2 billion, and added the most recent billion in 12 years

Due to exponential growth, even if the growth rate remains steady, population will continue to grow

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Es9mated Human Popula9on Growth

Popula9on distribu9on •  Increased density impacts the environment, but relieves pressure in less-‐populated areas

•  Humans are unevenly distributed around the globe –  Unpopulated areas tend to be environmentally sensi9ve

Two Demographic Worlds

•  Periphery is poor, young, and rapidly growing. •  Contain 80% of world popula9on, and will account for 90% of projected growth.

•  Core is wealthy, old, and mostly shrinking. •  Average age is about 40. •  Popula9ons expected to decline.

•  The forma9on of new borders, such as those created in Africa in the 1960s when former European colonies became independent, has kept nomadic popula9ons within prescribed fron9ers.

•  The result is the overgrazing of marginal grassland and deser9fica9on – the expansion of the desert, se`ng popula9ons of en9re countries, such as Ethiopia, at risk.

Some fear falling popula9ons •  Popula9on growth is correlated with poverty, not wealth

•  Policymakers believe growth increases economic, poli9cal, military strength – They offer incen9ves for more children – 67% of European na9ons think their birth rates are too low

–  In non-‐European na9ons, 49% feel their birth rates are too high

What’s Behind Popula9on Growth

•  Three Factors –  Fer9lity –  Infant Mortality –  Longevity

•  Animal Domes9ca9on and Agriculture –  Provided for a few to feed many

•  Industrial Revolu9on –  Growth of Ci9es and Infrastructure •  Water •  Energy •  Transporta9on

–  Increased Produc9vity –  Nutri9on –  Sanita9on – Medicine

Causes and consequences of popula9on growth

• 

Three Technological Eras

Popula9on & Technology Nexus INDUSTRIAL REVOLUTION

•  First phase: began in the 18th century and lasted into the 19th century. Called as preparatory period. All produc9on were made by hand.

•  This period was marked by a shih from wood as the primary energy source to coal.

•  By 18th century, wood was a scarce resource in Europe and almost all of the European forests had been cut down and replanted.

•  Demand for wood was a driving force behind the English encouragement of colonies in the New World.

•  Transi.on to coal = mass produc.on. •  Dominant technology: handwork


•  Second Phase: involved the replacement of human labour my machine labour. The prime example of this process was the development of the mechanical loom , which replaced coiage handwork with linen nad coion goods woven on mechanical machinery in factories.

•  Energy course: coal •  Dominant technology: steam engine, mechaniza.on of labour


•  Third Phase: beginning of automa9on by 19th century. Development of electricity powered by petroleum and natural gas. Oil was discovered by 1850s.

•  Mass produc9on assembly line: Henry Ford •  The development of plas9cs generated the throwaway society.

•  Energy source: gasoline, electricity •  Dominant technology: Automobile, airplane, electric light


•  Fourth Phase: The microchip, biotechnology and advanced materials ushered in the fourth phase and ohen called as «informa9on revolu9on».

•  Computers revolu9onized society. •  Energy source: Electricity, natural gas, wind, solar

•  Dominant technology: Computer, fiberop.c cable, TV, cellphone, biotechnology

•  This phases also brought unpleasent environmental surprises.

WHAT IS THE IMPACT OF TECHNOLOGY ON PLANET EARTH AND

GLOBAL POLITICS? •  INTERCONNECTEDNESS OF THE INDUSTRIAL REVOLUTION, SCIENCE AND TECHNOLOGY, POPULATION GROWTH AND ENVIRONMENTAL POLLUTION


GLOBAL POLITICS? •  Firstly, technology has served to improve the condi.ons of people and lead to rapid popula9on growth.

•  On the other hand, the cost of housing, educa9on, and the easy First World kind of life style has turned the birth rate on its’ head in the industrialized world and caused a sharp reduc.on in the birth rate in all regions of the world, with the excep9on of Africa.


GLOBAL POLITICS? •  Secondly, with every new scien9fic or technological advance, there is upside and downside.

•  The downside is twofold. As a technology matures, (1) drives out the compe99on and (2) builds economic and social links within society to enable the mass produc9on of the product.

•  The eventual result is «technological monoculture» where alterna9ve modes of the same technology do not come on the market.


GLOBAL POLITICS? •  The third aspect is «environmental surpise» •  Sooner or later, nature responds to every human ac9vity.

Is popula.on growth really a problem?

•  Popula9on growth results from technology, sanita9on, food – Death rates drop, but not birth rates

•  Some people say growth is no problem – New resources will replace depleted ones – But, some resources (i.e., biodiversity) are irreplaceable

•  Quality of life will suffer with unchecked growth – Less food, space, wealth per person

Popula9on growth affects the environment

•  The IPAT model: I = P x A x T x S –  Our total impact (I) on the environment results from the interac9on of popula9on (P), affluence (A) and technology (T), with an added sensi9vity (S) factor

–  Popula9on = individuals need space and resources –  Affluence = greater per capita resource use –  Technology = increased exploita9on of resources –  Sensi9vity = how sensi9ve an area is to human pressure –  Further model refinements include educa9on, laws, ethics

Humanity uses 1/3 of all the Earth’s net primary production

Demography •  Demography = the applica9on of popula9on ecology to the study of humans – Demographers study popula9on size,

– Density and distribu9on, – Age structure, sex ra9o, – And birth, death, immigra9on, and emigra9on rates

Demography •  All popula9on principles apply to humans –  Environmental factors limit popula9on growth

•  Humans can raise the environment’s carrying capacity through technology –  How many humans can the world sustain? 1 – 33 billion

–  Popula9on growth can’t con9nue forever

A changing age structure poses challenges

•  Many popula9ons are ge`ng older – Older people need care and financial assistance –  But, also reduces the number of dependent children and crime rates

Demographic Transi.on

•  Demographic transi.on (DT) refers to the transi9on from high birth and death rates to low birth and death rates as a country develops from a pre-‐industrial to an industrialized economic system.

Popula9on growth depends on various factors

•  Whether a popula9on grows, shrinks, or remains stable depends on: – Rates of birth, death, and migra9on – Birth and immigra9on add individuals – Death and emigra9on remove individuals

•  Technological advances led to drama9c decline in human death rates – Widening the gap between birth rates and death rates resul9ng in popula9on expansion

Immigra9on and emigra9on play large roles

•  Refugees flee their home country as a result of war, civil strife, and environmental degrada9on –  25 million escape poor environmental condi9ons – Movement causes environmental problems with no incen9ves to conserve resources

Emigra9on and Immigra9on

•  Emigra9on and Immigra9on play a large role in human popula9on dynamics.

– Developed regions expect 2 million immigrants a year for next 50 years.

– Locals complain immigrants take away jobs and overload social services.

Poverty and popula9on growth are correlated

•  Poorer socie9es have higher growth rates than wealthier socie9es –  Consistent with the demographic transi9on theory –  They have higher fer9lity and growth rates, with lower contracep9ve use

99% of the next billion people added will be born in poor, less developed regions that are least able to support them

Wealth also produces severe environmental impacts

•  The popula9on problem does not exist only within poor countries

•  Affluent socie9es have enormous resource consump9on and waste produc9on – People use resources from other areas, as well as from their own

–  Individuals’ ecological footprints are huge

One American has as much environmental impact as 6 Chinese or 12 Indians or Ethiopians

GLOBAL COMMONS

•  The concept of global commons derives from the common or commonly used land was once situated at the center of rural towns in England two centuries ago.

•  Today, the global commons define are those parts of the biosphere that are held in common by all humanity.

•  These include oceans, outer space, the seabed, Antarc.ca, the electromagne.c spectrum and the atmosphere.

Our ‘Commons’ are in Danger

•  Atmospheric pollu9on and climate change •  Water pollu9on, including ground aquifers •  Deforesta9on and loss of oxygena9on •  The oceans, •  Na9onal park •  Nonrenewable natural resource deple9on – Fossil fuels, mineral ores, topsoil…..

Biodiversity is in Danger

•  Humanity has spawned a species ex9nc9on to rival the 5 great ex9nc9ons of 65 -‐ 440 million years ago

•  Recovery 9mes from the great ex9nc9ons took 10’s of millions of years

•  Biodiversity is essen9al to life on Earth and holds untold treasures for the future

•  An ecological ethic is emerging

Conclusion

•  The human popula9on is larger than at any 9me in the past •  Popula9ons are s9ll rising, even with decreasing growth rates •  Most developed na9ons have passed through the

demographic transi9on •  Expanding rights for women slows popula9on growth •  Sustainability requires a stabilized popula9on in 9me to avoid

destroying natural systems

Conclusion

•  Environmental problems are not equally distributed and therefore effect each region and each country differently

•  Every environmental remedy has its’ costs •  Every state has a different capacity to pay the cost of environmental remedia9on. The US, Western Europe and Japan can afford to undertake costly pollu9on control problems. On the other hand, poorer states accuse the rich states of having caused the problem and demand the rich states pay for the demage. (China also refuses)

Conclusion

•  Awareness on environmental problems is rela9vely new.

•  Rachel Carson’s book ‘Silent Spring’ published in 1961, turned America on to the extent and scope of our current environmental problems and marked the beginning of the modern environmental movements.

•  Environmental problems are hard to resolve for a variety of factors. Chiefs among these are:

(1) The long period of elapsed 9me between technological innova9on and its’ environmental surprise.

(2) The scien9fic uncertainty surrounding every environmental problem ( global warming?)

(3) The reluctance of governments to take ac9on that may undermine economic growth or destabilize society in the absence of strong public pressure or clear scien9fic evidence.

human&population,& environment… · human&population,&...

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