We lay there and looked up at the night sky and she told me about stars called blue squares and red swirls and I told her I’d never heard of them.Of course not, she said, the really important stuff they never tell you. You have to imagine it on your own.

- Brian Andreas -

POPULATION

POPULATION SIZE YEAR TIME REQUIRED TO DOUBLE

1 billion 1850 all of human history

2 billion 1930 80 years

4 billion 1975 45 years

8 billion (projected) 2025 50 years

POPULATION IS GROWING AT AN EXTREMELY RAPID RATE.

IN ONE WEEK, APPROXIMATELY 220,000 PEOPLE JOIN THE HUMAN RACE – THE EQUIVALENT OF THE CURRENT POPULATION OF WINSTON-SALEM.

IN 3 YEARS, THE HUMAN POPULATION INCREASES APPROXIMATELY EQUAL TO THE CURRENT POPULATION OF THE U.S.

BY 2025, IT WILL APPROACH 8 BILLION.

WHY??

WHY??

• BETWEEN 8000 BC AND 4000 BC, HUMANS WENT FROM BEING HUNTER-GATHERS TO SUBSISTENCE AGRICULTURE

• IMPROVEMENTS IN AGRICULTURE CONTINUED WITH THE DEVELOPMENT OF THE PLOW AND IRRIGATION

• AT THE START OF THE INDUSTRIAL REVOLUTION, NEW FORMS OF MACHINERY WERE INTRODUCED

• THIS WAS FOLLOWED BY IMPROVEMENTS IN HUMAN HEALTH

• IN THE 1930’S AND 1940’S, ANTIBIOTICS WERE INTRODUCED ALONG WITH PESTICIDES

POPULATION EQUATION

POPULATION CHANGE = (NEW BIRTHS + IMMIGRATION) – (DEATHS + EMMIGRATION)

REALIZE THAT IMPROVEMENTS IN HEALTH PLAY A LARGE PART IN THIS EQUATION.

MOST SPECIES CANNOT IMPACT THEIR CARRYING CAPACITY.

HUMANS ARE UNIQUE IN THEIR ABILITY TO MODIFY THE ENVIRONMENT TO THEIR OWN ADVANTAGE AND CHANGE THE EARTH’S CARRYING CAPACITY FOR HUMANS.

THIS, IN TURN, DECREASES THE PROSPECTS OF OTHER SPECIES.

-USE OF PESTICIDES

-LOSS OF HABITAT

-POLLUTION

-OVER FISHING AND OVER HUNTING

RESOURCES USE PRODUCTS

WASTE

RESOURCES USE PRODUCTS

WASTE

SUSTAINABILITY

WHAT IS THE CARRYING CAPACITY OF EARTH FOR HUMANS?

MANY SCIENTISTS BELIEVE THAT THE 2005 POPULATION OF 6.5 BILLION ALREADY EXCEEDS THE CARRYING CAPACITY.

THE IMPACT OF HUMAN POPULATION CAN BE SEEN EVERYWHERE.

CONSIDER THE CRISES IN:

-EASTERN CONGO

-DAFUR

-BANGLADESH

-MIDDLE EAST

THE HUMAN POPULATION CURRENTLY CONSUMES ABOUT 40% OF THE PLANT MATTER PRODUCED ON LAND.

IF THE POPULATION DOUBLED, EARTH WOULD BECOME ONE HUGE FARM FOR HUMANS.

APPROXIMATELY 20% OF THE WORLD’S POPULATION DO NOT HAVE ADEQUATE SANITATION. THIS INCLUDES CLEAN DRINKING WATER AND SEWAGE.

THE CONDITIONS ARE ESPECIALLY BAD IN LARGE CITIES.

SCIENTISTS USE THE TERM INNER CITY SYNDROME TO DESCRIBE THIS PROBLEM.

DEFINITION: POPULATION DENSITY – THE NUMBER OF ORGANISMS PER UNIT AREA.

“WHEN THE POPULATIOPN DENSITY IS TOO GREAT, ALL INDIVIDUALS ARE INJURED BECAUSE THEY COMPETE SEVERELY WITH EACH OTHER FOR NECESSARY RESOURCES.”

- Enger and Smith, “Environmental Science” -

IN 1819, THE POET SHELLY WROTE, “HELL IS A CITY MUCH LIKE LONDON.”

IF HE WERE ALIVE TODAY, HE MIGHT WRITE, “HELL IS A CITY MUCH LIKE CAIRO, CALCUTTA, SHANGHI, BANGKOK, LONDON, LOS ANGELES, MEXICO CITY, AND OTHER.”

INNER CITY CROWDING AND POLLUTION HAS BEEN LINKED TO A WIDE RANGE OF PHYSICAL AND MENTAL PROBLEMS INCLUDING:

-PRENATAL DEATH - DIVORCE

-CRIME RATES - MENTAL ILLNESS

- ASTHMA

- DRUG AND ALCOHOL ABUSE

GROWTH RATE AND DOUBLING TIME

Region Growth Rate, % Doubling Time, years

World 1.2 58

Developed 0.1 700

Developing 1.5 47

Africa 2.4 29

Asia 1.3 54

North America 0.5 140

Latin America 1.6 44

Europe - 0.2 --

Oceania 1.0 70

SHORT OF NUCLEAR WAR ITSELF, POPULATION GROWTH IS THE GRAVEST ISSUE THE WORLD FACES …….. IF WE DO NOT ACT, THE PROBLEM WILL BE SOLVED BY FAMINE, RIOT, INSURRECTION, AND WAR.

- ROBERT MCNAMARA, FORMER WORLD BANK PRESIDENT -

SCIENTISTS ESTIMATE EARTH’S CARRYING CAPACITY FOR HUMANS FROM 500,000 TO 1000 BILLION.

DIFFERENCES IN ESTIMATES ARE BASED ON THE ASSUMPTIONS MADE ON STANDARD OF LIVING AND AVAILABLE TECHNOLOGY.

THINK WHAT WOULD HAPPEN IF EVERYONE:

- LIVED FRUGALLY

- RECYCLED

- USED PUBLIC TRANSPORTATION

- LIVED IN SMALL HOMES

- USED ENERGY EFFICIENTLY

WHAT ELSE MIGHT THEY HAVE TO DO?

AS POPULATION INCREASES, WHAT GENERALLY HAPPENS TO POLITICAL SYSTEMS?