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HS415
 Environmental Health
 Unit 6
 Greenhouse Gases, etc
Greenhouse Gases
 Carbon Dioxide 35% increase since industrial age
 Combustion of Fossil Fuels
 Deforestation
 Methane 154% increase since industrial age
 Animal (cattle and sheep) gas
 Nitrous Oxide
 Water Vapor
Climate Change Controversy
 Nobody argues that the earth is getting warmer and
that climate change is occurring.
 Controversy is global warming part of the natural
planetary cycle or does man have influence?
 Other issue is whether curbing CO2 emissions now
will have a real impact in the immediate future.
Kyoto Protocol: UN Agreement
 Protocol signed by 167 countries: US and Australia
notable exceptions
 China and India have signed on
 Cut greenhouse gas emissions by 5% less than 1990
emissions.
 If unable can purchase carbon credits but are
penalized in the future.
 Treaty expires 2013
Unintended Consequences of Climate
Change
Overpopulation: Feed Me!!!
 Pollution
 Improper Waste Disposal
 Depletion of Natural Resources
 Overcrowding/ Slums: Mixing of Human and Animal
populations
 Increased Consumption
What’s the cause?
• Power plants, cattle, and cars are some of the major
contributors of greenhouse gases such as carbon
dioxide and methane. For decades human factories
and cars have spewed billions of tons of soot and
greenhouse gases into the atmosphere, and the climate
has begun to show some signs of warming. We
produce millions of pounds of methane by allowing
our trash to decompose in landfills and by breeding
large herds of methane-belching cattle. Nitrogenbased fertilizers, which we use on nearly all our crops,
release unnatural amounts of nitrogen oxide into the
atmosphere.
What’s the cause? (cont.)
 Once these carbon-based greenhouse gases get into
the atmosphere, they stay there for decades or longer.
According to the Intergovernmental Panel on Climate
Change (IPCC), since the industrial revolution, carbon
dioxide levels have increased 31 percent and methane
levels have increased 151 percent. Paleoclimate
readings taken from ice cores and fossil records show
that these gases, two of the most abundant greenhouse
gases, are at their highest levels in the past 420,000
years.
Overpopulation
 Scientists estimate that around 10,000 years ago, only
about 5 million people inhabited the earth.
 By C.E. 1650, there were perhaps 500 million, and by
1800, 1 billion.
 Between 10,000 years ago and C.E. 1650 population size
doubled 71 times.
Overpopulation
 Dates and associated population estimates up to the
present are as follows:
 mid-1800s, 1 billion
 1930s, 2 billion
 mid-1960s, 3 billion
 mid-1980s, 4 billion
 present, 6.5 billion +
Overpopulation
• Human Population Growth
– Rate of growth increased due to better:
•
agriculture, sanitation, medicine, energy sources
• Overpopulation
– Started few centuries ago
– Is a global problem
• Population Grows Exponentially
Effect of Population on Earth
Resources
 Degradation of the environment by pollution
 Pollution: Unfavorable alteration of our surroundings,
wholly or largely as a by-product of human action
 Serious shortages of resources (including food)
 Is brought by straining Earth’s ability to provide food,
clothing, shelter, and energy
 e.g., on the average, each of us, on a yearly basis, uses:

500 kg of steel, 25 kg of Al, 200 kg of salt
Human Influences …
• Our daily activities are having measurable
effects on:
– Rainfall
– Climate
– Air
– Water quality
– Erosion
– Mineral resources
•
In North America, we use 20 tons of
mineral resources per person/year
Deforestation
• Deforestation contributes to global warming, since
we’re reducing the number of trees available to absorb
carbon dioxide.
• In the tropics, trees are burned as land is cleared, a
practice that releases yet more carbon dioxide.
• An estimated 20% of all carbon dioxide emissions are
accounted for by the burning of the Amazon rain
forest alone.
System Approach
• The whole Earth behaves like an organism
• It is a self-regulating network of interdependent
physical and biological systems
• A disturbance (e.g., deforestation) in one part of the
system (Earth) must result in adjustment in other
parts (e.g., global warming)
Quick Quiz
The problem that is linked to all other life forms and is
therefore the most important problem facing
human beings is
a)
b)
c)
d)
population increase.
competition for resources.
polluted air.
loss of biodiversity.
Tag…..your it.
 So what are YOU and your family going to do?
 Getting involved does not mean having to give up the
comforts we work so hard to get and provide.
 Call or email your Congressperson and Senators on
both the Federal and State levels.
 Meet your local Water Authority, City Council, Public
Health Dept….etc.