ASE: Theoretical Methods for the Calculation of Global Warming Potentials

lørdag 10 januar 2009, kl. 14:02 | Publisert i Klima, Konferanser og kurs | Legg igjen en kommentar
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Bilde av Ronald Reagen: Politikere – hva vet de om science? – 1979: 80% av forurensningen komemr fra planter og dyr. 1988: biler mer enn trær. 1966: et tre er et tre

 

Don quayle: 1988 ikke forurensningen, men det som er i luft og hav

 

Hydrocardigans don prescott

 

Outline:

  1. Greenhouse effect
    1. Radiation balance (ujevne fordelingen av solstrålingen på jordens overflate, samt utstrålingen fra jorden, som er mer jevnt fordelt).

                                                               i.      Ein=Fs(1-A)*Pi*R2

                                                             ii.      Eout=4*Pi*R2*s*Te4

  1.  
    1. Temperature of the earth

                                                               i.        Te = 256K (men global temp er 288K)

                                                             ii.      Fs = solar konstanten

  1. Earth and the planets
    1. Plot temperature against 1/r1/2

                                                               i.      Passer ikke for Venus, some r mye varmere

  1.  
    1. Electromagnetic spectrum.
    2. Greenhouse effect can happen because of difference in the radiation from the sun and from the sun
    3. Vibrating molecules – with music Muse

                                                               i.      Reason for temperature absorption

                                                             ii.      Interaction between temperature and vibration, electric field, frequencies (correct one)

                                                            iii.      Atmospheric warming

1.      vibrational energy is transferred to the surrounding molecules (CO2) og varmer atmosfæren

  1.  
    1. why venus hotter?

                                                               i.      965 000 ppm CO2

                                                             ii.      Atmosphere 93 times as dense

                                                            iii.      Why more CO2? Run-away-greenhouse effect

                                                           iv.      Water content – phase diagram for water is important

                                                             v.      Venus never reaches the point where you get water in liquid or solid, all vapour à greenhouse effect and hot

                                                           vi.      At hight temperatures CO2 is released from carbonates in the planetary crust

  1.  
    1. Temperature on earth – 256K or 288K?

                                                               i.      256K – balance between energy going in and energy going out

                                                             ii.      288K is greenhouse effect

1.      look at earthshine viewed from space – black body radiation from the earth

2.      remember CO2, O3 og H2O, stops some of it (not perfect graph)

  1. Carbon dioxide
  2. Particles in the atmosphere
    1. Studerer så strålingspådriv, sammenligner verdier for året 2000 med verdier for 1750
    2. Aerosols

                                                               i.      Reflects radiation

                                                             ii.      Absorbs radiation from the sun

                                                            iii.      Second organic aerosol: look blue, scatter radiation from the sun

  1. Ozone depletion
    1. Ozone in the lab

                                                               i.      Warm up ozone

                                                             ii.      Appelsinskall oppi, inneholder myrcene

                                                            iii.      Reagerer med terpenes (C10H16)

                                                           iv.      Reagerer med organiske forbindelser

  1.  
    1. Climate change and ozone depletion

                                                               i.      Ozonhullet 1987

                                                             ii.      KNMI/ESA

                                                            iii.      Cause of the ozone hole

1.      cold of the Antarctic vortex

2.      angular momentum is conserved (windspeed increases)

3.      low temperatures cause polar stratospheric clouds to form

a.       HCl + ClONO2 à Cl2 + HNO3

4.      sun comes up

a.       Cl2 is photolysed

b.      Fritt Cl bryter ned O3

5.      at high altitudes (low pressures) excited CO2 emits radiation leading to cooling, which may exacerbate the ozone hole problem

  1. Calculating global warming
    1. SF5CF3 – most potent greenhouse gas in the atmosphere
    2. Global warming potensials

                                                               i.      0,99x + 68.93 (men jeg vet ikke hva x er)

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ASE: Climate Change – A Risky Business

lørdag 10 januar 2009, kl. 13:32 | Publisert i Geofag, Klima, Konferanser og kurs | Legg igjen en kommentar
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Dette viste seg å være et foredrag om klimamodellering, som egentlig ikke ga meg så veldig mye ny informasjon. Jeg klipper inn mine notater direkte, uten korrekturlesning…

Policy responses to cc: mitigation and adaptation

Problem w/adaptation or mitigation: need to know how much change

Effect of uncertainties in planning adaptation:

  • planning for highest à waste money
  • lowest prediction: jeopardize
  • procrastination

 

So how do we model the earths climate, what to predict? Why uncertain?

Future climate I determined by: natural variability (chaos)(ex: el nino, la nina, NAO); natural factors as solar radiation (can’t be forecasted), volcanoes (aerosols); emissions of greenhouse gases (power stations, livestock, rice, aircraft); how the climate system responses on the human activities (how clouds, ice, oceans respond to greenhouse heating)

Stages:

Emissions – scenarios from population, energy, economic models

Concentrations – carbon cycle and chemistry models

Heating effect – properties of the greenhouse gases

Climate change – climate gases

Impacts – impact models

A climate model:

Ocean divided into 20 layers (100kmx100km), soil into 5 layers, atmosphere into 19 layers (300kmx300km)

Halvveis: Endelig viser han forskjellene i de ulike modellene! Har brukt en halvtime på å snakke om modellering.

Why uncertain: kjenner ikke bidraget fra naturlig variabilitet, kjenner ikke hvor mye utslipp vi vil ha, og iallfall ikke hvordan responsen vil bli.

Usikkerheten er stor på regional skala (som om det var merkelig?)

 

Hvorfor usikkerhet?

Skyer: lave skyer avkjøler, høye skyer varmer klimaet – MEN skyene vil endres i fremtiden, størrelsen på dråper, ispartikler etc vil endres, og disse vil få en stor feedback på klimaet

 

Dagens modellresultater gir ”eksakte” verdier – målet er å gi statistiske verdier – sannsynligheten for at det blir si eller så. Trenger derfor monte carlo kjøringer

Modelvariabler: atmosfære, hav, soil, …

 

Sannsynlighetsfunksjoner: ”Gauss” og akkumulert (pdf – probability distribution … over 10% og under 90%, eksempelvis)

 

Problemer: hva med metan? Gasshydrater, permafrost, våtmarker…

Kan brukes sammen med risk assessment

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