Download Climate Change Notes

Climate
Change
Weather vs. Climate
• The earth’s climate is
dependent on the weather
over a long period of time.
•Weather is what is
happening now or in
the near future.
Weather includes:
temperature, rainfall,
wind & humidity.
•Climate refers to the
average weather
over a long period of
time.
Climate Variability
•Variability is the
changes that occur in
daily temperature &
precipitation.
• Although an area's
climate is always
changing, the changes
do not usually occur on a
time scale that's
immediately detectable
to us.
• Weather patterns and
climate types take similar
elements into account, the
most important of which
are:
•The temperature of
the air
•The humidity of the
air
•The type and amount
of cloudiness
•Air pressure
•Wind speed and
direction
•Although weather and
climate are different,
they are very much
interrelated.
•A change in one
weather element
often produces
changes in the others
and in the region's
climate.
• For example, if the average
temperature over a region increases
significantly, it can affect the amount
of cloudiness as well as the type and
amount of precipitation that occur. If
these changes occur over long
periods of time, the average climate
values for these elements will also
be affected.
•Good and accurate
weather records have
only been recorded for
the last 130 years.
•Scientists use the
following techniques
to find the climate of
the earth’s past.
Clues in the ice –
• looking for tiny air
bubbles that form
when greenhouse
gasses are emitted
•Also looking for soot
particles to indicate
when forest fires
happened
Clues in Sediment
•Often have stored
pollen grain, plant
parts that grew in the
past
Clues in tree rings
• All of these methods provide
clues to past temperature,
precipitation, and wind
patterns as well as the
chemical make-up of the
atmosphere.
Greenhouse Gas Effect
• Greenhouses are structures
that are designed to hold in
heat.
Greenhouse Gas Effect
• The heat-trapping ability of
a greenhouse is influenced
by several factors:
1. Transparency of the
greenhouse cover
2. Color of inside
surfaces
3. Types of surfaces on
the inside
•The earth’s
atmosphere acts like
an insulating blanket
that is just the right
thickness.
• The “blanket” is a collection
of atmospheric gases
called greenhouse gases
that trap heat just like the
glass walls of a greenhouse.
• While the earth’s
temperature is dependent
upon the greenhouse-like
action, the amount of
heating & cooling are also
influenced by several
factors:
1. Type of surface that the
sunlight first encounter
Forests, grasslands, ocean,
ice caps, deserts & cities
all absorb and reflect light
differently
• Sunlight falling on white
glaciers will strongly reflect
back into space.
• Sunlight falling on a dark
desert soil is absorbed.
• Cloud cover
Greenhouses Gases
• any gas in the atmosphere
capable of absorbing
infrared radiation (heat)
reflected from the earth’s
surface
Carbon dioxide
• Sources:
• Burning fossil fuels
• plant matter
• Deforestation
• volcanic eruptions
Water Vapor
• Source:
• Evaporation (water cycle)
Nitrous Oxide
• Sources:
• Fertilizer production
• burning fossil fuels & wood
• agricultural soil (nitrification
& denitrification)
Methane
• Sources:
• Decomposition
• livestock waste
• decomposing waste in
landfills
CFCs
• Sources:
• Manufacturing &
industrial processes
Global Warming vs. Climate Change
• Global warming: trend towards
increasing temperatures. 10
warmest years on record have
occurred since 1990.
• Global climate change: changes
in precipitation, temperatures,
storm intensity. Global warming can
lead to global climate change.
Proof….
• 20th century was hottest on record
• Since 1861, average global temperature
has risen between 1o- 1.4o F (most of
that has been since 1980)
• 16 hottest years on record have been
since 1980, 10 hottest have been since
1990.
• Glaciers and sea ice are shrinking.
• Sea level rising (4 to 8 inches)
1979
2003
Artic sea ice
Factors affecting Earth’s temps
• Oceans can store heat and
CO2, but no one knows
how much.
• Cloud cover: can warm by
trapping and releasing heat
or cool by reflecting heat
back to space (albedo
effect)!
Factors affecting Earth’s temps
• Outdoor air pollution:
aerosols can either warm
or cool the atmosphere
(much like clouds)
Factors affecting Earth’s temps
• Stimulate photosynthesis:
more CO2 can temporarily
cause higher
photosynthesis.
Temporary because plants
will “level off” and die,
releasing their CO2
Factors affecting Earth’s temps
• Methane trapped under ice
is released when the ice
melts.
Implications of
Climate Change
Implications:
1) Plant growth
changes
2) Water supply
3) Diseases
4)
5)
6)
7)
8)
Soil quality
Displaced pollution
Droughts/Floods
Glaciers melting
Sea levels rising
9) Warmer water temps
10) Coral bleaching
–Algae & coral are
losing their bright
colors…b/c the algae
are dying from the
warm temps.
10) Ocean acidity
11) Migration patterns
12) Food production
13) Desertification
–An area experiencing
desert like condition…
lack of water, etc.
1. Use and production of
energy
• Efficiency and conservation
• Alternative sources – Wind,
solar, hydroelectric
2. Transportation
• Efficiency of vehicle
• Drive less….public
transportation
3. Agriculture and Forestry
• Soil and forest absorb carbon
dioxide
• Careful farming practices can
keep soil in place to help it
hold carbon.
• Trees planted to replace
those that are cut down.
4. Cap-and-Trade
• Government put a limit or
cap on the amount of
greenhouse gases that can
be released by an industry.
If industry releases less
than they are allowed to
sell their “allowances” to
another company.
5. Carbon Tax
• A fee that a government
changes polluters for each
unit of greenhouse gases
they emit.
• European countries have
done this.
• Downside…extra costs
passed on to the
consumer.
6. Carbon Offsets
• Instead of reducing
greenhouse gas emissions,
an industry or person
voluntarily pays another
group or person do to so.
Example: Someone taking an
airplane ride…feels guilty about
the amount of greenhouse
gases emitted so pays an
organization to plant trees that
will absorb carbon dioxide to
compensate for the emissions
used by the plane.
7. Carbon Sequestration
• Way to capture and store
carbon
• Stored underground but
no guarantee that is may
not leak out
8. Kyoto Protocol
• Is an international agreement
that seeks to limit
greenhouse gas emissions
The treaty is binding which
means the countries that
signed it MUST commit to
reducing greenhouse gases.
• The US did NOT sign the
treaty.
9. Copenhagen Accord
• Developed nations pay
billions of dollars to
developing nations to fund
the reduction of
greenhouse gases.
• Developed nations also
agreed to set specific
targets for emission
reduction by 2020.
• This is not a binding treaty
& a disappointment to most
nations.