Kl

1
Klímaváltozások Adatok, nagyságrendek, modellek
Rácz Zoltán
Institute for Theoretical Physics Eötvös
University E-mail racz_at_general.elte.hu Homepage
general.elte.hu/racz
Problémakör Mi a klíma és mit jelent a
változása? Mi a szokatlan?
Jégkorszakok 100 ezer éves periódusának
eredete. A tudományos
és társadalmi problémák keveredése.
Kérdések Mit ismerünk a múltból
(adatsorok)?
Releváns ido- és távolságskálák
Mi hajtja a klímát meghatározó
folyamatokat?
Energia- és energiaáram-skálák
Modellek Térbeli struktúrák jelentosége
Lehetséges-e
hirtelen változás?
Skálák- és effektusok keveredése
Üvegház jelenség
atmosphere
ocean
Epilógus A véleményváltás valószínusége,
avagy
léteznek-e boszorkányok?
2
Boszorkányok és a kis jégkorszak
W. Behringer Witches and Witch-Hunt, A Global
History
(Cambridge, 2004).
E. Oster, J. Econ. Perspectives (2004).
Pápai bulla (1484) Boszorkányok képesek
idojárásváltozást okozni.
s
elégetett boszorkányok száma
átlag
homérséklet eltérése az átlagtól
év
-s
1520 1600
1700 1770
Következtetések Boszorkányokról
Klímakontrollról
Központi beavatkozásról
Racionalitásról Statisztika
problémáiról
L. Reynmann (1514) Von warer erkantnus des
Wetters (Igaz ismeretek az idojárásról)
3
Kontinensvándorlások és klímaváltozások
4
14 millió évvel ezelott
5
ice
Last 65 million years
water
natural
6
Last 5 million years
M.E. Raymo and K. Nisancioglu, Paleoceonography,
20, PA1003 (2003)
?
7
Accuracy of data
Last 725 thousand years
pressure shear roughness
8
The last 430 thousand years
Slow cooling
Fast increase (starting from low T-s!)
9
Az utolsó 123 ezer év a jégkorszak
finomszerkezete
DO (Dansgaard-Oeschger) oszcillációk
Fiatal driász
10
Last 15 000 years Differences between north and
south
11
Last 120 000 years Fluctuations of temperature
12
Az utolsó 40 év
13
Features we would like to understand

• t gt -800 ky
• strong 100 ky period
• weaker 41 ky period
• Directionality
• Saw-tooth Slow cooling, fast warming
• t lt -800 ky
• 100 ky period disappears
• 41 ky period dominating
• North and south are synchronized

• Fluctuation spectrum is continuous
• S(?) ?-1.8 ?-2.2

14
Energies and energy fluxes Characteristic times
energy perturbation
relaxation time of the perturbation
incoming energy flux
Atmosphere
Ocean
Ice fields
Ice field height
Tropo- sphere
Thermal mixing
albedo
Weather fronts
Gulf stream eddies
15
Glacial periods and orbital eccentricity
M. Milankovich (1930)
Problems
(1) Two orders of magnitude missing (2) 400 ky
period
16
Spectrum of orbital eccentricity
Power spectrum
Problems
400 ky period missing 100 ky not quite well
placed extra periods
17
Periods of Earth (Milankovich 1930)
G. Bacsák
Excentricity (100 ky) small effect 0.1
Precession of axis of rotation (19, 23 ky)
Affects intensity of seasons.
Angle of inclination (41 ky)
Changes distribution of insolation. Insolation
at North Pole
max min 90 0
http//www.ncdc.noaa.gov/paleo/
18
Insolation intensity at the edges of the
icefields
How do we get a 100 ky period from JE?
19
Insolations and insolation differences
20
Threshold models
J. Imbrie and J.Z. Imbrie, Science. 207, 943
(1980)
Complexity of models Number of parameters in
data model
-V(t)
dO18
D. Paillard, Nature 391, 378 (1998)
21
A threshold model in more detail
W. H. Berger, Int. J. Earth Sci. 88, 305 (1999)
- ice volume
Ice fields grow

• Ice fields unstable if
• It is too large
• (gravitation)
• Insolation is large
• and growing

30 ky
Fitting
22
Problems with the treshold model
W. H. Berger, Int. J. Earth Sci. 88, 305 (1999)
Power spectrum
Problems
400 ky period missing extra frequencies
23
Improving the threshold model
W. H. Berger, Int. J. Earth Sci. 88, 305 (1999)
t
Memory effects
(Effects of the ice flields?)
Average ice volume in the last t years
Fit
24
Internal drive Feedbacks and oscillations
E. Kallen, C. Crafoord, and M. Ghil, J. Atm.
Sci. 36, 2292 (1979)
B. Saltzman and A. Sutera, J. Atm. Sci. 41, 736
(1983)
H. Gildor and E. Tziperman, J. Geophys. Res. 106,
9117 (2001)
How to get oscillations?
( nonlinear terms)
Example
Mapping on to d1
Temperature (T)
Precipitation (P)
Ice (V)
Albedo (a)
Thresholds and/or memory is needed.
25
Sea-ice switch
H. Gildor and E. Tziperman, J. Geophys. Res. 106,
9117 (2001)
Box model for Tland, Tsea, Vland, Vsea
Warm
rate
rate
model for growth (M) and ablation (S)
Cold
rate
rate
26
Sea-ice switch 100 ky period
H. Gildor and E. Tziperman, J. Geophys. Res.
106, 9117 (2001)
Rate of growth of ice-shields
ablation rate
maximal minimal precipitation rate
Rate of decay
Period
ice
hard to determine but use
27
Stochastic resonance and the 100 ky period
R. Benzi et al., Tellus 34, 16 (1982), C.
Nicolis, ibid. 34, 1 (1982)
Temperature (T)
time
0.07C
eccentricity drive
3C
U(T)
internal noise

T
timescale
deterministic dynamics
28
Are there two stationary states?
U(T)
T
Does it follow? No.
Prob. distribution of T
J.D. Pelletier, J. Geophys. Res. 108, 4645 (2003)
T
29
Stochastic resonance The mechanism
R. Benzi et al., Tellus 34, 16 (1982) C. Nicolis,
Tellus 34, 1 (1982)
Temperature (T)
T
time
time
U(T)
T
eccentricity

noise
timescale
deterministic dynamics
30
Derivation of the deterministic part
G. Matteucci Clim. Dyn. 3, 179 (1989)
Energy balance
outgoing infrared radiation, parametrized as
incoming radiation
albedo
greenhouse may be included here
a0
large ice-fields
no ice
heat capacity of Earth
T
T0
31
Adding the drive
G. Matteucci, Clim. Dyn. 3, 179 (1989)
outgoing infrared radiation may be affected by
the seasonality
Energy balance
incoming radiation
nonlinear effect
Noise
Gaussian white noise
32
Adding memory
J. D. Pelletier, J. Geophys. Res. 108, 4645 (2003)
noise
bistability
Vostok
memory
(lithospheric effects)
solves the problem of directionality
Similar observations
Vostok
E. Koscielny-Bunde et al., Phys.Rev.Lett. 81, 729
(1998)
J. D. Pelletier and D. L. Turcotte,
Hydrology, 203,
198 (1997)
33
Adding noise to sea-ice switch model
Y. Ashkenazy et al. J.Geophys.Res. 110, C02005
(2005)
Dynamics of ice-shields of volume V
noise
ablation
Growth slows down when ice volume is large
off
on
Memory of and !
V0
memory term needed for directionality
34
Bolygóközi por és a Föld pályasíkjának billegése
R.A. Muller and G.J. MacDonald, Nature 377, 107
(1995)
Problémák 33000 éves memória, Mechanizmus?
35
Üvegházhatás Por, vulkán, aeroszolok, CO2,
36
Üvegházhatás CO2 Mi hajt mit?
Pozitiv visszacsatolás?
37
Üvegházhatás CO2, H2O, CH4
bejövo
kimeno sugárzás spektrális
felbontása
11 km magasan
Üvegház gázok absorbciós spektruma
tenger- szinten
38
Globális felmelegedés
JONES e-mails CHRISTY
July 5, 2005. The
scientific community would come down on me in no
uncertain terms if I said the world had cooled
from 1998. OK it has but it is only 7 years of
data and it isn't statistically significant.
1120593115.txt
39
17300010 w
Energy fluxes
12
1
tides
Direct reflection
0.30
-5
210
0.47
Direct change into heat
Volcanos, hot springs
-6
210
Energy storage
0.23
Evaporation, precipitation, etc.
in water, ice
-3
210
Energy flow from Earth
Wind, waves, currents, convection
-4
210
-4
decay
210
Photosynthesis
Energy storage by living matter
-6
310
humans
-6
-4
110
210
industry
Earth
coal, oil, gas
Nuclear and thermal energies
40
Az energiafelhasználás fejlodése
Szükséges terület 100 napenergiából 100-os
effektivitás
2
Watt m
Gyüjtögeto életmód 100
0.3 A tuz megszelidítése
200 0.6 Kezdeti
mezogazdaság 600
1.8 Kezdeti iparosodás (1850) 3500
10 USA (1970)
11500 34 USA (2008)
13000 38
41
Energy-future Where will it come from?
The level would we like to live US2008.
Tides No Volcanos,
hot springs No Heat flow from Earth
No Photosynthesis No Coal, oil,
gas Yes Nuclear energy
? Wind
? Solar ?
Needed area for 100 solar energy 10
effectivity
The level would we like to live US2008. World
population 6.8 109 Land area of Earth 4p
(6106m)20.3
1.5 1014 m2 Area needed 6.8
109 380m2 2.5 1012 m2 Europe
1.0 1013 m2

42
Gates on Copenhagen
Agreement in Copenhagen Channel
100 billion per year to developing
countries to combat climate change by 2020.
Has a 34 billion fundation for fighting
malaria etc. in developing countries.
Gates 100 billion per year is more
than ¾ of foreign aid currently given
by the rich countries. I am concerned
that some of this money will come from
reducing other categories of foreign aid,
especially health. If just 1 of the
100 billion came from vaccine funding
then 700 000 more children could die
from preventable diseases.
Taking the focus away from health aid could be
bad for the environment in the long run because
improvements in health, including voluntary
family planning, lead people to have smaller
families, which in turn reduces the strain on the
environment.
43
Do witches exist if there are two large
hurricanes in a century?
hurricans are caused by witches (idea)
more than 2 hurricans occurs in a
century (phenomena)
If , then the probability of is big
Outset we do not know
If , then the probability of is small
Probability of and
Probability of if happens
h
44
IPCC 2007 interpretációk
Fig. SPM-3
1850 1900
1950 2000
International Kiwi
International Papaya
Az utolsó 9 évben nem emelkedett a
Föld homérséklete
Legmelegebb évek 150 év óta 10-bol 8 az
utolsó évtizedben
IPCC Report
IPCC Report
Suzy Rácz
Nóra Rácz