Global Issues Global Issues and Human and Human

ImpactImpactWhat are YOU doing to help?What are YOU doing to help?

What are YOU doing to hurt?What are YOU doing to hurt?

Treat the Earth well, it was not given to you by

your parents, it was loaned to you by

your children. We do not inherit the

Earth from our Ancestors, we

borrow it from our Children.

OverpopulationThe first homo sapiens walked the earth 200,000 years ago.

It took until 1804 for the global population to reach 1 billion.

123 years later in 1927, it reached 2 billion.

34 years later in 1961, it reached 3 billion.

13 years later in 1974 it reached 4 billion.

13 years later in 1987 it reached 5 billion.

12 years later in 1999 it reached 6 billion.

Today it reached 7,010,830,027

In 2025 it is projected to hit 8 billion!

OverpopulatiOverpopulationonEarth’s Carrying Capacity

• In 1961 the earth had 3 billion people. They were using ½ of the Earth’s resources.

• In 1987 the earth had 5 billion people. They were using ALL of the resources.

Ever since then we have been putting TOO MUCH

stress on the planet!!

►overexploiting fisheries. ►overgrazing to the point of desertification. ►destroying forests. ►polluting the waters and atmosphere, including greenhouse gasses.

At the rate we are going, we will need 2 WHOLE planets to sustain our appetites by 2050.

Something has obviously

got to give!!

How it How it Hurts!!Hurts!!Because of the stress we are putting on the planet

several global issues are now SERIOUS problems. DeforestationDeforestation Acid RainAcid Rain Ozone DepletionOzone Depletion Biological MagnificationBiological Magnification Global WarmingGlobal WarmingThese are NOT the only problems caused by overpopulation…but they are the ones we will focus on.

DeforestatiDeforestationon

Two MAIN reasons:1. Raw materials (paper, housing, firewood, etc.)2. Space (industrial use – homes, schools, factories, etc)

The cutting down of trees WHY?

There are, of course, other reasons…but these are the main reasons

So What!?!So What!?!What are the consequences of deforestation? NUMEROUS!!

Here are the main consequences:

1.More CO2 and Less O2 – due to a lack of photosynthesis2.Increased soil erosion and lower soil quality3.Loss of habitats for animals – this disrupts food webs & ecosystems4.Screws up the water cycle - lessens the amount of transpiration & lowers the water table

In 1960 a person with leukemia had a 1 in 5 chance of survivalIn 1980 the chance of survival was 4 in 5

This was due to the Rosy Periwinkle

Out of 32 common chemotherapy drugs…28 of them came from plants!!

So far scientists have only explored 1% of plant and animal species for medicinal use.

Scientists estimate that 100 species go extinct every day!!

Loss of Loss of BiodiversityBiodiversity

What happens if you need a medicine one day to survive…but we killed off the plant species that it comes from?

BiodiversitBiodiversityyThe Pacific Yew tree

Source of Taxol a widely-used breast cancer medicine

Acid RainAcid Rain

• Sulfur Dioxide (SO2) and Nitric Oxides (NOx) are emitted as car exhaust and factory emissions.

• They combine with water vapor in the atmosphere forming acid droplets.

• They become part of the water cycle…and fall to the Earth as acid

precipitation.

So What !?!So What !?!• Rivers, streams and lakes become acidic

– Fish and other aquatic species die

• Ground water can become acidic – Vegetation and trees die

Acid rain affects trees by washing away the minerals and nutrients in the soil that help trees to grow.

Normal RainAcid Rain

Concrete, marble and stone are weakened

Over 40% of the nations bridges and overpasses and

“structurally deficient”That means they could

collapse!!

BEFORE

AFTER

Ozone Ozone DepletionDepletion• We have already explored the Ozone…what

does it do for us?

CFC’s – Banned in CFC’s – Banned in 19781978Chlorofluorocarbons were found in:

styrofoamair conditioners & refrigeratorsaerosol cans

How Does CFC Destroy How Does CFC Destroy Ozone?Ozone?

Is it Worth Is it Worth it?it?

Ozone Depletion was recognized as a Global issue around 1975.

It took until September 24, 2010 for the ozone damage to FINALLY stop!

Scientists thinkthat the Ozonewill regain itshealthy densityaround 2050.

75 years later!!

Can we afford to wait 75 years tosolve our otherGlobal Issues?

BiomagnificatBiomagnificationionWhen chemicals (like pesticides) are added to the ecosystem, they get into the food web…

Pesticides are often NONBIODEGRADABLE, this means they DO NOT BREAK DOWN!!

As animals eat other animals, the chemicals build up in their body…causing serious illness or death!!

DDT (a spray to kill mosquitoes) caused the death of most Bald Eagles – putting them on the Endangered Species List for 40 years (1967-2007)

Thiscan

food

affectANY

chain!!

Even the ones HUMANS are a part of!

Biological Biological MagnificationMagnification

Biological Biological ControlsControlsUsing a natural predator is an environmentally

friendly way to control pests!!

No chemicals added into the ecosystem!

BUT BUT BEWARE!!BEWARE!!You need to be careful when adding a species

into an environment…they could TAKE OVER!!

Cane Toad

Global Global Warming!!Warming!!

Greenhouse Effect vs. Global Greenhouse Effect vs. Global WarmingWarming

Greenhouse Effect ☼ NORMAL trapping of some of the Sun’s heat ☼ Keeps our planet warm enough to support life

Global Warming

☼The thickening of the atmosphere with greenhouse gasses (CO2, CH4 and N2O)☼More of the Sun’s heat gets trapped…increasing the planet’s temperature.

Causes of Global Causes of Global WarmingWarming

• Two main causes for higher levels of CO2

1. Increased burning of fossil fuels (cars, factories, etc.)

2. Increased deforestation is limiting the conversion of CO2 back into O2 for us to breathe

An Inconvenient An Inconvenient TruthTruthhttp://learningaboutpolitics.eu/greeksite/tag/climate-change/

So What!?!So What!?!Spread of disease

As northern countries warm, disease carrying insects migrate

north, bringing plague and disease with them.

Some of the consequences of global warming:

Warmer Waters – More Hurricanes

As the temperature of oceans rises, so will the probability of more

frequent and stronger hurricanes.

Increased Probability and Intensity of Droughts and

Heat WavesAlthough some areas of Earth will

become wetter due to global warming, other areas will suffer

serious droughts and heat waves. Africa will receive the worst of it, with more severe droughts also expected in Europe. Water is already a dangerously rare

commodity in Africa, and according to the Intergovernmental Panel on Climate Change, global warming

will exacerbate the conditions and could lead to conflicts and war.

Polar Ice Caps MeltingThe ice caps melting is a four-pronged danger.

First, it will raise sea levels. With all glaciers melted, the seas would rise about 230 feet.

Second, melting ice caps will throw the global ecosystem out of balance. The ice caps are fresh water, and when they melt they will desalinate the ocean, or in plain English – make it less salty.

The desalinization of the Gulf current will "screw up" ocean currents, which

regulate temperatures.

Third, temperature rises and changing landscapes in the Arctic Circle will endanger

several species of animals. Only the most adaptable will

survive. Fourth, global warming

could increase with the ice caps gone. Ice caps are

white, and reflect sunlight, much of which is reflected back

into space, further cooling Earth. If the ice caps melt, the

only reflector is the ocean. Darker ocean absorbs

sunlight, further warming the Earth.

Other Other ConsequencesConsequencesFloodsStronger Storms

WildfiresDesertification of Soil

Loss of Biodiversity & HabitatsSpecies Extinction

Diminished Food & Water SupplyDeath of Phytoplankton

Phytoplankton do MORE THAN 50% of the planets

photosynthesis!!

Phytoplankton do MORE THAN 50% of the planets

photosynthesis!!

Time to Change Your Time to Change Your Thinking!?!Thinking!?!

How Do We Fix These How Do We Fix These Issues?Issues?• We will talk about this when we get back from

the break!!How can

YOU reduce

your human

footprint?