Transcript Document

Resources and the Environment
 Natural resource- is found in nature and can be used
by humans
 Renewable resources – can be replenished within a
lifetime
 Ex. water, wind, solar, geothermal
 Nonrenewable resources - form over millions of years
 Ex. nuclear power and fossil fuels (coal, natural gas,
oil)
 Sun is the ultimate source of most energy on
Earth.
– The Sun’s energy is transferred from photosynthetic organisms to
all other living things.
Traditional Sources of Energy
Biomass- material from living or recently
living organisms
• Wood
• Field crops
• Dried fecal material
• Peat
These are all renewable sources
Energy Resources Worldwide
• Industrialized countries90% nonrenewable sources
(petroleum, coal, natural gas, nuclear)
10% renewable sources (biomass,
water, solar, wind, geothermal)
• Developing countries59% nonrenewable sources
41% renewable sources
2004 Worldwide Energy Sources graph
Global energy usage in successively
increasing detail (2005)
Nonrenewable Energy Sources- Fossil Fuels
Fossil Fuels- coal, oil, natural gas
 Fossil fuels, such as natural gas, coal, and
petroleum, are non-renewable resources formed
from organisms that lived millions of years ago.
Pros:
 Can be used for both vehicles and electricity
generation
 Efficient energy source
Cons:
 Burning of fossil fuels releases sulfur and nitrogen
oxides into the atmosphere; creates air pollution.
 Burning produces carbon dioxide and water vapor
(greenhouse gases) which may contribute to global
climate change.
Another Nonrenewable Energy
Source- Nuclear Energy
• Nuclear energy involves the fission of U235
Nuclear Power Pros and Cons
Pros:
• Does not release greenhouse gases
• Does not contribute to acid rain
• Very efficient energy source
Cons:
• Safety concerns (accidents, terrorist strikes)
• Radioactive waste
Alternative Energy Resources
These are all renewable
• Solar
• Water (Hydroelectric)
• Wind
• Geothermal
• Biomass
Look over pros and cons for each in the
table on page 184 of your Resources handout
Land Resources
• Soil
• Fossil fuels- formed from ancient
remains of plants and animals
• Ore- a mineral or rock that can be
mined for profit
Human Impact on Land Resources
• Agriculture may lead to a loss of topsoil and
also involves fertilizers and pesticides
• Urbanization involves loss of ecosystems due
to construction of cities
• Deforestation occurs when trees are removed
and not replanted;
– Leads to topsoil erosion
– Also changes the carbon cycle
http://www.ozcoasts.org.au/indicators/Images/carbon_cyclefig1.jpg
Carbon “sinks” and “sources”
Human Impact on Air Resources
• Air is 78% nitrogen, 21% oxygen and less than
1% water vapor, carbon dioxide, argon
• Burning fuel (wood, coal, etc.) produces
particulate matter (small particles) that may
damage lung tissue
• Burning of fossil fuels release greenhouse
gases (such as water vapor; CO2, methane)
• Burning fossil fuels also releases sulfur
dioxides and nitrous oxides which contribute
to acid rain
The Greenhouse Effect
• Short wavelength radiation from sun passes
through the atmosphere and warms Earth
• Long wavelength (infrared)energy is trapped
by greenhouse gases (H2O; CO2, methane,
nitrous oxide, ozone) and keeps Earth
consistently warm
• Increased GH gases can lead to increased
temps on Earth (now that’s global warming)
Greenhouse Effect
The greenhouse effect results from the trapping of
radiation by gases in the atmosphere (H2O; CO2,
methane, nitrous oxide, ozone are major greenhouse
gases)
-this is a natural process, but humans are adding
increased levels of greenhouse gases to the
atmosphere by burning fossil fuels
Global Warming
• Many sci believe increased levels of
greenhouse gases are leading to global
warming (gradual increase in Earth’s temp)
Climate change info…
• Earth’s average surface temp has increased
about 1°F in last century
• According to NOAA: 7 of the 8 warmest years
on record have occurred since 2001 and the
10 warmest years have all occurred since
1995.
Natural v. Human Causes of
Global Warming
• Greenhouses gases (like CO2, H2O) heat Earth’s
atmosphere and cause global warming
– Natural sources of CO2 gas- volcanic
eruptions, decay of organic (plant, animal)
matter, cell respiration, etc.
– Human sources- burning of fossil fuels for
transportation, heating, energy production
Greenhouse Gases
continued….
• Each greenhouse gas differs in its ability to
absorb heat in the atmosphere.
– Carbon dioxide (CO2) – 1
– Methane (CH4) - 21 times CO2
– Nitrous oxide ‐ 310 times CO2
– HFCs ‐ 1,300 to 6,500 times CO2
• These numbers convert everything into carbon
dioxide equivalents
Why does burning fuel create
greenhouse gases?
Remember the equation for combustion?
Fuel + oxygen  carbon dioxide + water + energy
– Combustion causes almost every atom of carbon in
the fuel to combine with 2 atoms of oxygen
-1 gallon of gasoline yields about 19 pounds of carbon
dioxide (plus water vapor, and soot) when burned.
Add to that the 6 pounds of CO2 needed in the
manufacturing and transportation of the fuel, for a
total of 25 pounds of carbon dioxide
From the Counting Carbons article
• 1 gallon of gasoline  25 pounds CO2
• 1 kilowatt‐hour of electricity  1.64 pounds of CO2
• 1 cubic foot of natural gas  0.12 pounds of CO2
• 1 gallon of heating oil  26.04 pounds of CO2
Ozone (O3)
• “Good” ozone occurs naturally
in the Stratosphere (upper atmosphere)
-absorbs harmful UV radiation from sun
• “Bad” ozone occurs in the troposphere (near
the ground) as a result of pollution (sunlight
breaks up NOx, CO, other hydrocarbons);
makes up smog
CFCs- Chlorofluorocarbons
• Used in propellants, fridges; ACs;
cleaning electronic parts
• Montreal Protocol banned the use of
CFCs (1987)
• Ultraviolet (UV) radiation breaks down
CFCs and the chlorine destroys “good”
ozone
http://www.thewe.cc/
weplanet/poles/antarc
ti/ozone.html
CFCs- Chlorofluorocarbons
• Used in aerosol cans,fridges; ACs;
cleaning electronic parts
• Montreal Protocol banned the use of
CFCs (1987)
• UV radiation breaks down CFCs and the
chlorine destroys “good” ozone
Montreal Protocol 1987
• International treaty designed to protect the
ozone layer
• Called for the phasing out of production and
use of CFCs and HCFCs (responsible for ozone
depletion)
Kyoto Protocol 1997
• Set targets for 37 industrialized countries and
the European community for reducing
greenhouse gas emissions
• Reductions amount to an average of five per
cent (against 1990 levels) over the five-year
period 2008-2012.
Water Resources
• 97% of water on Earth is salt water
• 3% is freshwater, but less than 1% is potable
(drinkable)
Why?
• Water shortages occur mostly in Africa and
Middle East; we see shortages in the U.S. in
western states (CO, AZ, CA)
Water Cycle
Human Impact on Water
• Point pollutionfrom a single
location (ex.
sewage treatment
plant, factory)
• Nonpoint pollutionfrom many
locations (acid rain,
runoff, fertilizers,
manure)
Some Major Water Pollutants
Pollutant
Source
Nitrates
Phosphates
Metals (Mercury, Lead)
Fertilizers, wastes
Fertilizers, detergents
Industry, fuels, acid rain
drainage
fuels
Oil, gasoline
Sustainable Energy
• Policy that will meet energy needs without
causing harm to the planet
– Involves energy efficiency and renewable energy
• Only possible if many countries work together
and are committed to this