Weather

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WeatherClimateClimate ChangeOzone Depletion

• what does it all MEAN?

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Question Whats in the atmosphere?

• N2 (78)
• O2 (21)
• Ar (0.9)
• WV
• CO2
• O3
• Particulates

(greenhouse gas)
(greenhouse gas)
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Thermosphere
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TROPOSPHERE

• Gases here moderate flow of energy to E.
• 10 mi thick _at_ tropics 5 mi thick _at_ higher lats.
• Contains all the WV clouds.
• Weather occurs here!
• Temp ? as altitude ?.
• Pollutants can rise to top within days...
• TROPOPAUSE caps it...temp stops decreasing.

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(higher...) STRATOSPHERE

• Temp ? as altitude ?...
• Contains O3 (it absorbs radiation).
• Persistent substances

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What happens to TEMP as you go farther away from
E?Why does it warm up in the stratosphere?
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What happens to the TEMP as you move farther from
E?
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Good to know...

• Weather day-to-day variations in temp, precip,
  wind, pressure, humidity.
• Climate long-term regional weather patterns.
• Factors affecting climate
• Latitude
• Atmospheric circulation
• Oceanic circulation
• Topography
• Solar activity
• Volcanic activity

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Latitude
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Latitude

• LOW latitudes close to equator receive more
  direct (vertical) rays more concentrated E per
  surface area.
• No winterno summerall hot.
• HIGH latitudes receive less direct (oblique)
  rays less concentrated E per surface area.
• Wider temp range, seasons!

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Warm air rises (low pressure...)Cold air sinks
(high pressure...)Pressure flows from HIGH to low
Atmospheric Circulation (wind)
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Latent Heat

• Warm air holds more WV than cool air
• Warm air rises (less dense)
• As moist/warm air rises, it cools WV condenses
  to liquidclouds form
• Latent heat (trapped in WV) is released
• Energy source for t-storms, tornadoes,
  hurricanes.
• QUESTION will increased temps lead to more
  WVmore latent heatresulting in more intense
  severe weather?

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How OCEANS affect temp...

• HEAT CAPACITY water stores heat more effectively
  than solid earth (heats up cools more slowly
  than land).
• HEAT TRANSFER ocean currents carry warm
  equatorial water towards poles.
• SOURCE for WV when wv condenses in the
  atmosphere it releases latent heat.

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Surface Currents
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One cycle 1,000 years
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El Nino-Southern Oscillation (ENSO)
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• Solar Maximum
• - Increased UV
• - Increased O3
• - Increased temps

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• - SO2 gas reaches
• upper atmosphere.
• SO2 dust WV
• form haze.

- Haze reflects sun- light, global temps
decrease.
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the seasons!
And finally
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Greenhouse Effect

• Analogy sunlight pours into your car heats up
  the interior (gets absorbed by seats, dash, etc)
  as its converted from light energy to heat
  energy (IR).
• The light energy escapes back out through the
  glass...but the heat energy is blocked by the
  glass and so cannot leave the car.
• Much like a greenhouse.

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Greenhouse Effect

• The Greenhouse Gases - WV, CO2,CH4, N2O are
  analogous to the glass in a greenhouse.
• Light energy from Sun passes through them,
  strikes E and is converted to heat energy
  (IR)...the converted IR is absorbed and
  re-radiated back into the troposphere by the
  GHGs.

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Your diagram goes here!
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ABSORBED 70 REFLECTED 30
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An important 70...

• The solar energy not reflected back into space
  (70) gets transferred to the atmosphere as IR
  energy...
• This warmed-up air becomes less dense, rises, and
  creates air currents called convection cells.

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...its actually a good thing...

• The greenhouse effect moderates the temp and
  makes it warm enough for many ( a word that often
  leaves you guessing) life forms to exist...

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...a force to be reckoned with.

• HOWEVER... If the concentration of these GHGs
  changes, their insulating effect changes
  also...and so will our climate.

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Enhanced Greenhouse Effect

• 1958 Charles Keeling begins measuring CO2 levels
  on Mauna Loa

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Anthropogenic warming

• Warming of the Earth derived from human activity

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...climate change is such an important issue
today because we depend on those orgs for vital
goods services we need to survive...
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If the global climate changes, can these
ecosystems change with it - so those vital goods
services continue?
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CLIMATES

• ...remember how ecosystems biomes result from
  different combos of temp precip?
• ...and the orgs that inhabit a particular biome
  are adapted to those limits?
• HUMANS can live anywhere (we dont have to adapt
  we control the environment...)

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Past Climates

• Global surface temps fluctuate!
• This chart is
• modern... stats
• come from actual
• weather stations.

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...but what about long ago?

• Proxies are used to provide info about ancient
  climate conditions.
• Pollen deposits...marine sediments...coral...ice
  cores... historical data

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Pollen!
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Marine sediments

• Biological
• Changes in fossilized orgs (type amount)
• Oxygen isotope concentrations in shelled remains

• Inorganic
• Clay mineralogy
• Aeolian dust

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Coral

• Greer and Swart were investigating the
  relationship between non-radioactive or stable
  isotopes of oxygen in the calcium carbonate of
  the coral. The ratio of normal to heavier oxygen
  depends on the temperature of the water the coral
  grew in and its salinity. In warmer water, the
  coral incorporates more of the normal oxygen into
  its structure, but if the water is cooler, the
  coral will incorporate a higher percentage of the
  heavier oxygen isotope.

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Medieval Warming PeriodLittle Ice Age
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What does it MEAN?

• Es climate has oscillated between ice ages and
  warm periods.
• Milankovich cycles Earth rotational
  revolutionary movements combine to affect global
  climate.
• Theory Ice ages are caused by 100,000 year
  coincidences of these cycles.

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...during the ice ages, major amounts of water
were tied up in glaciers ice sheets...sea
levels dropped hundreds of feet below current
levels.
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Rapid changes...

• Younger-Dryas Event at the end of the last ice
  age, E warmed up 7o C in just 50 years!
• Scientists scratch heads most likely due to
  atmosphere / ocean / global temp combo... kind of
  an El Nino gone bad...

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THERMOHALINE Circulation

• Whats THAT mean?
• Thermo heat......Haline salty...
• Cold water is more dense than warm water
  Saltier water is more dense than fresher water.
• Warm salty water cools sinks _at_ poles...flows
  along ocean bottom towards equator where it warms
  rises.

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One cycle 1,000 years
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...could the conveyor belt be STOPPED?

• Recent evidence shows that it has been
  interrupted in the past...six times.
• Large quantities of fresh water in the North
  Atlantic (glacier/ice pack melting...) would
  lower the salinity (density) of the water up
  there... water would stop sinking...
• The northward flow of warm water would be blocked
  and the belt shifts south.
• Results in ABRUPT global cooling.
• Scientists are monitoring salinity in the
  northern ocean...

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Climate Change the DATA.
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1 CO2

• Released by burning of fossil fuels!
• Annual oscillations are due to seasonal changes
  in NH terrestrial ecosystems photosynthesis
  Apr-Sep CO2 ? respiration Oct-Mar CO2?
• As of 2012, CO2 levels _at_ 399ppm (40 higher than
  before the Industrial Revolution)...higher than
  theyve been in 400,000 years!

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Sources Sinks

• 1 kg combusted fossil fuel 3kg CO2
• 6.6 GtC (gigaton billion metric tons) per year
  of fossil fuel carbon.
• 1.6 GtC per year from burning forests.
• Sinks carbon sequestration.
• Oceans uptake by phytoplankton _at_ 2 GtC/year
• Forests _at_ 3 GtC/year

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2 WV

• Absorbs IR...the most abundant GHG! Atmospheric
  concentration variable...
• Major factor in Supergreenhouse effect in
  South Pacific, wv traps/reradiates heat over
  ocean, resulting in MORE evaporation, thus more
  wv, thus more greenhouse effect...positive
  feedback.

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3 Methane (CH4)

• Sources microbial fermentation (swamps,
  livestock, landfills, coal mines, natgas
  production, rice cultivation, manure).
• Atmospheric methane has doubled since Industrial
  Revolution is leveling off!

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4 Nitrous Oxide (N2O)

• Sources agriculture biomass burning fossil
  fuel combustion
• 15 increase in past 200 years.
• Particularly unwelcome because its so
  persistent residence time 114 YEARS!
• Also bad for O3...

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5 O3

• Sources motor vehicle exhaust, biomass burning.
• Short-lived, but potent.

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6 CFCs Halocarbons, et al

• Entirely anthropogenic.
• Sources refrigerants, fire retardants, solvents.
• Extraordinary capability for IR absorption
  (x10,000 CO2s rate)
• Long residence time (100 years)
• Double whammy GHG AND O3 destroyers!
• Good news manufacture use has been curtailed.

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IPCC

• Intergovernmental Panel on Climate Change.
• est. 1988 by UN and World Meteorological Society
  to provide accurate, relevant information on
  anthropogenic climate change.
• Three working groups
• I Assessment of scientific issues
• II Impact of climate change possible
  adaptations
• III Mitigation of effects

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IPCC

• More than 2,000 experts from over a hundred
  countries.
• Unpaid...recoup only the cost of their research
  associated professional activities.

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Most recent report Sep 2013
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The report finds that it is very likely that
emissions of heat-trapping gases from human
activities have caused most of the observed
increase in globally averaged temperatures since
the mid-20th century...
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...evidence that human activities are the major
cause of recent climate change is even stronger
than in prior assessments...
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It is unequivocal that Earths climate is
warming...
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...as is now evident from observations of
increases in global average air and ocean
temperatures, widespread melting of snow and ice,
and rising global mean sea level...
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...atmospheric concentrations of CO2 and methane
exceed by far the natural range over the last
650,000 years.
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Further findings/evidence

• 11 of last 12 years rank among top 12 hottest
  years on record since 1850.
• Tropical storms, precipitation, and severe
  drought incidence have all increased.
• Mountain glaciers and snow fields are in
  world-wide decline.
• Summer Arctic sea ice has decreased 20 since
  1978.
• Global mean sea level is rising.

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Whats been done...

• Rio 92 Earth Summit calls for voluntary
  reduction of GHGs.
• Failure all increased...
• Kyoto 97 binding agreement to reduce emissions.
• Failure major players non-participants.
• Copenhagen 09 ill-willmistrust between
  developed/developing nations.
• Details of the accord

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Latest IPCC Report (Sep 2013)

• The warming is unequivocal.
• Humans caused the majority of it.
• The warming is largely irreversible.
• Most of the heat is going into the oceans.
• Current rates of ocean acidification are
  unprecedented.
• We have to choose which future we want very soon.
• To stay below 2C of warming, the world must
  become carbon negative.
• To stay below 2C of warming, most fossil fuels
  must stay buried in the ground.

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Carbon Credit Trading

• Countries (both developed developing) receive
  an allowance of carbon production.
• Developing countries can initiate cleaner
  technologies using less carbon.
• They can trade unused carbon credits to other
  countries and use the profit to grow.
• Developed countries will either pay or change
• Market based.

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The future...?

• Confidence in computer models to predict future
  scenarios has increased...
• Human influences will continue to change
  atmospheric composition throughout the 21st
  century.

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B1 scenario pop? then?, economies governments cooperate to achieve sustainability
A1T scenario pop? then?, global shift to non-fossil fuel energy sources
B2 scenario pop?, significant efforts to achieve sustainability
A1B scenario pop? then?, balance of all energy sources
A2 scenario pop? then?, countries act independently with varied economic/technological change
A1F1 scenario pop? then?, fossil fuel intensive society
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Projected Surface Temp./Sea-Level Rise at Year
2090
Temp. (oF Change _at_ yr 2090) Sea-Level Rise ( _at_ yr 2090)
Case Best Estimate Likely Range Model-based range (excluding future rapid dynamical changes in ice flow)
Constant Year 2000 concentrations 1.1  0.5 - 1.6  NA
B1 scenario 3.2 2.0 5.2  7.1 - 15.0
A1T scenario 4.3 2.5 - 6.8  7.9 - 17.7
B2 scenario 4.3  2.5 - 6.8  7.9 - 16.9
A1B scenario 5.0  3.1 - 7.9  8.3 - 18.9
A2 scenario 6.1  3.6 - 9.7  9.1 - 20.1
A1F1 scenario 7.2  4.3 - 11.5  10.2 - 23.2
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Projected Surface Temp./Sea-Level Rise _at_ Year 2090
Temp. (oF Change _at_ yr 2090) Sea-Level Rise ( _at_ yr 2090)
Case Best Estimate Likely Range Model-based range (excluding future rapid dynamical changes in ice flow)
Constant Year 2000 concentrations 1.1  0.5 - 1.6  NA
B1 scenario 3.2 2.0 5.2  7.1 - 15.0
A1T scenario 4.3 2.5 - 6.8  7.9 - 17.7
B2 scenario 4.3  2.5 - 6.8  7.9 - 16.9
A1B scenario 5.0  3.1 - 7.9  8.3 - 18.9
A2 scenario 6.1  3.6 - 9.7  9.1 - 20.1
A1F1 scenario 7.2  4.3 - 11.5  10.2 - 23.2
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What Must Be Done.

• World-wide cap on GHG emissions.
• Investment in, deployment of renewable energy
  technologies.
• Removal of fossil-fuel subsidies.
• 10 billion/yr in Europe...15-35 billion/yr
  U.S.A.
• Develop nuclear power.
• Cost-effective, reliable, waste, spent fuel...
• More stringent energy conservation measures.

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What Must Be Done.

• Stop TRF loss plant more trees.
• Reduce the amount of fuels used in
  transportation.
• Sequester CO2 emissions.
• Slow HPG.

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Depletion of the Ozone Layer
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UV that penetrates the atmosphere may be absorbed
by biological tissues, where it damages proteins
and DNA molecules.
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If the full amount of UV from the sun reached Es
surface (without being absorbed by the
atmosphere), it is doubtful that any life forms
could survive.
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Fortunately, over 99 of UV is absorbed by ozone
in the stratosphere...
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...the small amount that does reach E is
responsible for more than 700,000 cases of skin
cancer/precancerous conditions per year, just in
North America.
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Formation and Destruction of Stratospheric O3

• O2 UVB ? O O
• O O2 ? O3
• O O3 ? O2 O2
• O3 UVB ? O O2

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Seasonal changes in distribution of solar
radiation cause ozone concentrations to vary...

• (High in summer, low in winter)

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Ozone concentrations are higher near the equator,
and diminish as latitude increases...also a
function of distribution of solar radiation.
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CFC (chlorofluorocarbon)

• Nonreactive, nontoxic, nonflammable organic
  molecules in which Cl Fl have replaced
  hydrogens gases _at_ normal temp pressure...
• ...they liquefy at modest pressure, giving off
  heat in the process, becoming cold...
• ...used in refrigerators, heat pumps, production
  of foam plastic, as propellants in aerosol cans.

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CFCs break down O3 in stratosphere

• CFCI3 UV ? Cl CFCI2
• CI O3 ? ClO O2
• CIO ClO? 2 Cl O2

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Chlorine acts as a catalyst a chemical that
promotes a chemical reaction without itself being
used up in the reaction.

• ...each chlorine can last from 40 to 100 years in
  the stratosphere...it has the potential to break
  down 100,000 molecules of ozone.

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...its not really so much a hole...

• ...its more like a bald spot.

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Rowland Molina

• Called it in 1974...published a paper that
  concluded CFCs would damage the stratospheric
  ozone layer, increasing UV radiation on Es
  surface, resulting in more skin cancer.
• Won Nobel Prize for their work (1995).

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1985

• British researchers in Antarctica report a hole
  over the South Pole (about the size of the United
  States) in the fall of 85...levels were 50
  lower than normal.
• NASA satellites would have discovered it first
  but they were programmed to reject anything over
  a 30 drop as an instrument failure!

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Surprise...

• Scientists thought that ozone loss would be
  gradual uniform all over the planet not a
  hole!
• The hole came as a surprise...if it had
  happened anywhere other than South Pole, UV
  damage to life would have been extensive.

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Why it happens where it happens

• Summertime creates chlorine reservoirs (Cl gets
  locked up in methane nitrogen compounds)
• Wintertimes extreme cold traps stratospheric
  gases within a ring of air circulating around the
  Antarctic...clouds form...clouds provide surfaces
  on which Cl2 gets unlocked from its reservoir.
• When sunlight returns in spring, UV attacks the
  Cl2, releasing free Cl which begins the ozone
  destruction cycle.

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Sad days in the Outback, mate...

• Ozone-poor air shifts over the Southern
  Hemisphere...
• UV radiation increases up to 20 above normal in
  Australia...
• Three out of four in Queensland (thinnest layer)
  are expected to develop skin cancer.

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Montreal Protocol

• 184 participating nations must phase out
  ozone-destroying chemicals by 2000 (developed
  countries) and 2010 (developing countries).
• ..in most industrialized countries, CFCs are no
  longer produced or used.
• Prediction the ozone shield will reach full
  recovery by 2050.