[Over]population and [Over]consumption
Population per Square Kilometer Original “Native” Habitat Remaining (50 countries – Paul Harrison)
The sheer impact of people on biodiversity (from McKee, J. K., Sciulli, P. W., Fooce, C. D. & Waite, T. A. Forecasting global biodiversity threats associated with human population growth. Biological Conservation(2003)).
294 people or less = 59% 379 people or less = 45% 454 people or less = 33% 1,190-1,888 = 15%
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So, how many people are there? http://www.ibiblio.org/lunarbin/worldpop
Overpopulation
According to the United Nations, in 2000 (sometime, September?) world population reached 6 billion people. In Asia, a baby 6 billion was welcomed at a Colombo hospital by her mother, Chrishanti Priyakumari; UNFPA's Sri Lanka Representative, Ms. Mukherjee; and Director of Maternal and Child Health, Dr. Vineetha Karunaratne.
A personal perspective
Why is this significant?
The same day as “baby 6 billion,” some 356,000 babies were estimated to be born in the world, 90 per cent of them in developing countries.
It took all of human history up to 1804 to reach a global population of 1 billion. It took just 12 years to leap from 5 billion to 6 billion.
This represents more than a doubling of population from the 1950 level of 2.52 billion.
I was born in 1968, the first of one
The world had about 3 billion people in it
My father’s generation
The world had about 2 billion when my father was born in Harrisburg, PA in 1936, as the 3rd of 6.
My son’s generation
The world population reached 6.6 billion people 11 August 2006 when my son was born
We are presently adding another 95 million every year!
By 2025, the world population, at current rates, will elevate to 8.6 billion people
My grandparent’s generation
The world had only about 1 billion when my maternal grandfather was born in 1906, as the first of 3.
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This class goes for about an hour. There will be about 15,000 more human beings on this planet at the end of my lecture than there were when I began. If I stop and take a deep breath--we are joined by about another 20 people.
Years per Billion Added to the Population (3) Year
Population
Time Increment
1804
1 billion
4 million years
1927
2 billion
123 years
1960
3 billion
33 years
1974
4 billion
14 years
1987
5 billion
13 years
1999
6 billion
12 years
2013
7 billion
14 years
2028
8 billion
15 years
2054
9 billion
26 years
World Population Distribution Dot Map
Satellite Monitoring of Artificial Light
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What has driven population growth?
The massive decline in infant mortality rates in the 20th century was the major cause of the population increase.
Changes in infant mortality rates
In 1950 the infant mortality rate exceeded 15%.
More than 15 children died for every 100 born (or one died for every 6 or 7 born).
By 1998 rate < 6%, or for every 17 or 18 children born, only one did not survive.
Infant Mortality
Fertility rates also are critical
Fertility = children produced per mother
A remarkable decline in fertility rates has occurred recently
Average global fertility has been halved
From a high of about 6 children per woman in the 1950s to 2.9 per woman today.
Demographers have been amazed at how rapidly fertility rates have dropped over the last few decades
Infant Mortality
Crude Birth Rate
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Total Fertility Rate
Factors related to lower fertility rates in women
Basic rights: decision-making in the home, voting, owning land, having a job
Education/Literacy
Knowledge of reproduction and contraceptive methods
Access to contraception
Income independent
Industrialized Nations: shifts in fertility
The United States, with 2.03 children per woman, has the highest fertility rate in the developed world.
The average fertility rate for European countries and Japan is 1.4.
Even in some developing nations such as South Korea and Taiwan, the rate is at or below 1.6.
So why doesn’t population growth slow down?
Even assuming a continued decline in fertility rates, the United Nations projects a population of 8.9 billion in 2050.
Under current trends, world population isn't projected to stabilize until sometime after 2080.
Why?
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“Population Momentum”
Where does the future lie?
• In many developing countries, more than half of the entire population falls within child-bearing ages (15-45).
The issue is the 3 billion people worldwide under the age of 25
Their reproductive and life choices will have an enormous impact on population growth rates
• The demographic structure of these countries means that their absolute population continues to grow, although the overall rate of increase is declining. • This phenomenon is known as population momentum.
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Where will future population growth occur?
Africa, with 13 percent of the world's population, is projected to see 34 percent of the globe's population increase over the next 50 years.
India and China combined will account for another 25 percent of the increase.
The United States
The current U.S. population is 299 million, making it the world's third most populous country
Projected to grow to 335 million by 2025
Most U.S. population growth is due to immigration and lower mortality rates
Where are we headed globally?
7.5 billion -- 11 billion?
Decline of fertility rates in developing countries will accelerate as a result of:
increased family planning efforts,
empowerment of women,
increased economic activity
Or death rates will soar as a result of water scarcity, starvation or disease, as has already begun in some areas
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[Over]Consumption
“Everything comes from somewhere”
How many is too many? •Pre-agricultural humans were at densities around 1.0 to 1.5 persons per square kilometer •Exploiting every corner of Earth’s habitable terrestrial surface = 130 million to 200 million pre-agricultural people.
Consumption
As a species, we are growing "bigger" not just in numbers, but as resource consumers.
In hunter-gatherer times, an average human consumed about 2,500 calories daily, all of it from food.
Today, however, humans use an average of 31,000 calories each day, most of it from fossil fuel.
Critical densities •1-2 people per square kilometer reflects how dense human populations can get, on average, before our species must modify the ecosystems we inhabit for our own survival. •Currently at 44 persons/square kilometer! •Suggests how dramatically we must now control our competitors, predators and parasites, in order to maintain our numbers.
Can our natural resources sustain a population of about 8 to 12 billion by 2050?
Must consider population and impact
Affluent peoples consume more in order to maintain their comfortable lifestyles
They also produce greater waste since they utilize "disposable items" manufactured from plastics, paper, and metal.
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More on energy
US constitutes 5% of the world's population but consumes 24% of the world's energy. On average, one American consumes as much energy as
2 Japanese, 6 Mexicans, 13 Chinese, 31 Indians, 128 Bangladeshis, 307 Tanzanians, 370 Ethiopians (a whole village, no?).
Ecological Footprints
Ecological footprint - the amount of land and resources used to meet a given country's consumption needs and to absorb the resulting wastes. Analogous to concept of carrying capacity When consumption exceeds local capacity, a country's ecological footprint may be greater than its total land area. Wackernagel et al. 2002. PNAS 99: 9266-9271
Globalization
One extreme example of over consumption…Pet food
International trade is a big part of the deficits in ecological footprint
Americans and Europeans together spend $17 billion a year on pet food
Ease of trade means that impacts are highly diffuse
Costs are not reflected in prices paid
$4 billion more than the estimated yearly additional amount needed to provide everyone in the world with basic health and nutrition.
$25 billion would secure all biodiversity hotspots on earth
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Our role?
Paper or plastic?
Consumers should learn about and consider the role of their purchases, their pets, and their daily activities in putting biodiversity at risk.
They should inform themselves about and consider how their lifestyles and their political choices influence native species and ecosystems.
The primary choices
Driving cars and light trucks Meat and poultry production … Growing produce and grains Household appliances and lighting Home heating and cooling Home construction Household water and sewage …
Driving - Transportation
Cars and light trucks cause the most environmental damage overall
Responsible for nearly half of the toxic air pollution and more than one-quarter of the greenhouse gases traceable to household consumption.
Fragmentation, sprawl, wildlife mortality
Because cars cause so much harm, even modest changes matter
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Food
Food is second only to transportation as a source of consumer-related environmental impacts.
Red meat causes especially high amounts of environmental damage for the nutrition it delivers.
Cutting the average household's meat consumption (both red meat and poultry) in half would reduce
food-related land use by 30 percent
common water pollution by 24 percent
Trophic pyramids and carnivory
Transfers of energy from one trophic level to the next are not very efficient. The usual approximation is that
10% of the energy in one level is converted to mass at the next level.
Choosing to have children…
How did we get to this point? Do we live in a myopic fog?
No longer a choice made in isolation -personal choices now have societal repercussions
"We have become the central organizing reality around which non-human life will evolve." Cincotta and Engelman.
Neanderthal
The brain evolved into its present form during a long stretch of evolutionary time People existed in small, preliterate huntergatherer bands. Life was precarious and short. Near future and early reproduction, and little else Quality of short-term decisions was the premium
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E. O. Wilson’s perspective…
Today the mind still works comfortably backward and forward for only a few years, spanning a period not exceeding one or two generations. Those in past ages whose genes inclined them to short-term thinking lived longer and had more children than those who did not. “Prophets never enjoyed a Darwinian edge!”
Subsequently…
Individuals place themselves first, family second, tribe third and the rest of the world a distant fourth.
Inherent conflict in an era of sudden globalization
Our genes seem to predispose us to plan ahead for one or two generations at most
The paradox: selfishness selfinterest
Being human and condoning biodiversity conservation are not incompatible
Individuals do act in their own self-interest and show restraint when realize future benefits outweigh future costs
All long-term conservation solutions must recognize this
In other words, collapse isn’t inevitable
End: Overpopulation and Over consumption
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