Global Issues and Human Impact What are YOU doing to help? 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.

Overpopulation The 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. Today it reached 7,010,830,027 In 2025 it is projected to hit 8 billion!

Ever since then we have been putting TOO MUCH stress on the planet!! Overpopulation Earth’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 Hurts!! Because of the stress we are putting on the planet several global issues are now SERIOUS problems. Deforestation Acid Rain Ozone Depletion Biological Magnification Global Warming These are NOT the only problems caused by overpopulation…but they are the ones we will focus on.

There are, of course, other reasons…but these are the main reasons Deforestation The cutting down of trees WHY? Two MAIN reasons: 1. Raw materials (paper, housing, firewood, etc.) 2. Space (industrial use – homes, schools, factories, etc) There are, of course, other reasons…but these are the main reasons

So What!?! What are the consequences of deforestation? NUMEROUS!! Here are the main consequences: More CO2 and Less O2 – due to a lack of photosynthesis Increased soil erosion and lower soil quality Loss of habitats for animals – this disrupts food webs & ecosystems Screws up the water cycle - lessens the amount of transpiration & lowers the water table

Loss of Biodiversity In 1960 a person with leukemia had a 1 in 5 chance of survival In 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!! What happens if you need a medicine one day to survive…but we killed off the plant species that it comes from?

a widely-used breast cancer medicine Biodiversity The Pacific Yew tree Source of Taxol a widely-used breast cancer medicine

Acid 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 !?! 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. Acid Rain Normal 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 Depletion We have already explored the Ozone…what does it do for us?

CFC’s – Banned in 1978 Chlorofluorocarbons were found in: styrofoam air conditioners & refrigerators aerosol cans

How Does CFC Destroy Ozone?

Is it Worth 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 think that the Ozone will regain its healthy density around 2050. 75 years later!! Can we afford to wait 75 years to solve our other Global Issues?