Branko GrisogonoDept. of Geophysics, Faculty of Science

Thanks to: . Brankovi & I. GttlerCroatian Weather Service (DHMZ)

On Recent Climate Change and Modeling Future Climate Scenarios

Data: Global Past, Present ? Future

Numerical Models (Simulators)

Climate vs. Weather

More of Current Results: Present Future

Regional Climate Change

Tentative Conclusions Discussion

IPCC 2007

Observed Data

bgrisog - Podaci motrenja i mjerenja nedvojbeno ukazuju na klimatske promjene od druge polovice proslog stoljeca pa sve do danas.

5th IPCC, late 2013 - observed data

5th IPCC, late 2013 - observed data

BASIC ISSUES:

- MEASUREMENTS, WITH THEIR ERRORS, ARE SPARSE IN SPACE & TIME. THUS, INITIAL STATE OF THE ATMOSPHERE & OCEAN IS ONLY KNOWN PARTLY

- NUMERICAL WEATHER PREDICTION (NWP) & CLIMATE MODELS CAN'T FULLY RESOLVE IN SPACE & TIME ALL THE RELEVANT PHYSICAL PROCESSES (ASIDE APPROXIMATIONS)

- ATMOSPHERES & OCEANS ARE INHERENTLY CHAOTIC BESIDESSTRONG DETERMINISTIC COMPONENTS

- The atmospheres behavior is governed by a set of physical conservation laws telling how the air moves (Newtons laws of motion), about heating-cooling (laws of thermodynamics), roles of moisture

- The governing Partial Differential Equations (PDEs) cant be solved analytically only numerical (i.e., approximate) solutions are possible

* Given the current state, I.C. & B.C., the equations may be used to pass the info forward in time forecast

* The observations give the sparse current state an incomplete picture, the weather & climate models may process the obs. a fuller picture of reality

Unresolved Processes ParameterizedParameterized: Radiation, Moist Processes, Turbulence,

Predictability, like Turbulence, is Flow Dependent

Weather vs. Climate ModelsResolution & integration length of the governing PDEs (motion, mass, thermodynamics, spicies)

Parameterizations (different space - & time-scales) e.g., weather models might have slight drift (may avoid some feedbacks, etc.) climate modes not!

Sometimes numerics, due to numerous couplings (feedbacks) being modeled differently, etc.

Oceans, soil, biosphere, ice, treated differently

IPCC 2007

ModelSimulations

Cedo Brankovic - Ako (globalni) modeli uvaze samo prirodno forsiranje, bez porasta plinova staklenika, onda ne dolazi do zagrijavanja. Ako se uz prirodno forsiranje uvazi i utjecaj covjeka (povecana koncentracija plinova staklenika), dolazi do zagrijavanja.

srednjak ansamblaTemp. at 2m, Summer (2011-2040) minus (1961-1990)

Branko - Razni modeli imaju razlicite parametrizacije fizikalnih procesa, pa tako mogu dati nepodudarne rezultate. No, u ovom primjeru se vidi da 3 globalna modela (EH5OM, HadGEM i GFDLCM) idu u istom smjeru - zagrijavanje atmosfere.

Regionalni model (RegCM) forsiran je s EH5OM rubnim uvjetima. Daje finiju strukturu polja koja je vezana uz bolju reprezentaciju orografije

Extreme EventsNo. Summertime Warm DaysNo. Wintertime Cold Days

Branko - Klimatske promjene ce imati, pored znacajnog utjecaja na srednjak, veliki utjecaj i na ekstremene vrijednosti raznih parametara.

Broj toplih dana u razdoblju 2011-2040.s ce se povecati u cijeloj Hrvtaskoj, osobito na Jadranu. Broj hladnih dana u zimi ce se smanjiti (noci ce postati toplije).

Global Cloud-Resolving Models (CRM)Satellite imageNICAM simulation at x = 3.5 kmFuture of Numerical Climate Modeling ?

5th IPCC, late 2013 - numerical simulations

Current surface temp. upward trends & future predictions are unusual, unexplained by natural internal climate variability

Predictions are based on greenhouse gas emission scenarios & a link between the gases concentrations & temp. through modeling & simulations

Included: population growth, economic development, technol. change, social interactions

Besides large spatio-temporal variations, global warming is real, it exceeds in magnitude & pace natural changes over the last 103 yr.TENTATIVE CONCLUSIONS

Immediate changes seem needed: lowering emissions of green-house gasses to meet the scenario with global ~ +2oC in yr. 2100

Targeting and promoting more human technologies, renewable energies, healthier food & water Humanistic approach needed!

It is wrong to deploy instrumental rationalism (max. efficiency only) & blind pragmatism based on e.g., large resources & markets

Make reliable regional climate economy projections for next few decades (agronomy, energy, tourism, education, etc.)TENTATIVE CONCLUSIONS contd

* Klimatske promjene imaju utjecaj na gotovo sve oblike ljudske aktivnosti

* Istraivanje meteorolokih aspekata klimatskih promjena - jedan od najveih izazova suvremene klimatologije (kompleksnost, prediktabilnost, ...)

* Istraivanje utjecaja klimatskih promjena na socio-ekonomske faktore (ublaavanje i prilagodba)

* U istraivanje klimatskih promjena ukljuen je veliki broj institucija i znanstvenika

* Vano definirati jasnu znanstvenu poziciju kako bi se mogue odluke zasnivale na znanstvenim injenicama primjer: potrebna je solidna znanstvena podloga kako bi se mogla opravdati novana ulaganja u energiju iz obnovljivih izvora

* Uloga klimatskog modeliranja i simuliranja nezaobilazna jedini nain kako predvidjeti klimatske promjene

* Odgovornost institucija i grupa ukljuenih u klimatsko modeliranje

* Poboljanje i unaprijeivanje globalnih i regionalnih klimatskih modela vezano i vrlo ovisno o razvoju: primjenjene i numerike matematike (PDE !), geofizike i raunalne tehnologije Za dalju diskusiju

IM ANAIR-CONDITIONED MIAOU-UU..but soon maybe dead..bgrisog@gfz.hrwww.pmf.unizg.hr/geof

5th IPCC, late 2013 - numerical simulations

Precipitation, winter (2011-2040) minus (1961-1990)

Branko - Slicno kao za temperaturu na 2 m. RegCM daje fragmentiranu oborinu, pa je signal nesto drugaciji od onog koji indiciraju globalni modeli (dipolnu strukturu promjene oborine - vlazniji sjever, suhlji jug).

Science humanities: many people are interested in global warming What are reliable temp. reconstructions for the past? -What are the best available temperature & climate predictions for this century? - Here well try to offer condensed & succint answers to those 2 questions.Znanost humanost: Mnoge ljude zanima opce zatopljenje kakve su pouzdane rekonstrukcije temperature u proslosti i kakve su najbolje raspolozive predikcije temperature i klime za ovo stoljece. Ovdje cemo pokusati ponuditi kondenzirane i sublimirane odgovore na ova 2 pitanja. Govoricu o klimi u zadnjih nekoliko 100 god. pa do nekoliko desetljeca u buducnosti.

1] DATA 1ST THEN NUMERICAL MODELS( SIMULATORS, NONE OF WHICH IS PERFECT BUT ONLY AN APPROXIMATION TO REALITY). NEXT: 1 of 2 MOST IMPORTANT SLIDES HERE.2] the climate is what you expect, the weather is what you get roughly speaking3] past climate change may be attributed to orbital changes, variations in solar output, volcanic eruptions, etc. For the recent period, anthropogenic forcings can be added.4] http://www.whitehouse.gov/photos-and-video/video/2014/01/08/polar-vortex-explained-2-minutesAGU EOS 2010, Fig.1 N.H.: A2 population grows at current rate to 15 bill. in 2100, heterogen. economic growth, local identities remain, +4C by 2100. A1B growth to 8.7 bill. by 2050 & drop to 7 bill. By 2100, efficient & balanced technologies, +2.5 C by 2100. B1 popul. like in A1B but countries come together, better technologies, envir. controls, < +2 C by 2100. C3 Keep everything as in 2000 effects of inertia, +0.4 C!- UZ SVE OVO, 90% LEDENJAKA NA SVIJETU SE TOPI VEC > 15-TAK GOD*Observations and measurements show climate change, definitely from the mid-20th century onward. Now focus on the last ~150 yr of the data as in the former plot!Climate is conventionally defined as the long-term statistics of the weather.Weather forecasting is usually treated as an initial value problemclimatology deals primarily with a boundary condition problem and the patterns and climate devolving (=prenijeti, ~= conveying) & evolving there from*Glob. zagrijavanje je nedvosmisleno jasno, i jako je vjerojatno da je covjek dominantan uzrok tome.CO2, CH4 [metan] i N-oksidi su postigli glob. koncentracije kakve nisu bile barem u zadnjih 800 000 god.1983-2012. je globalno vjerojatno najtopliji 30-god. period u zadnjih 1400 god. a 1. dekada 21. stlj. je najtoplija dekada od svih.Zajedno s topljenjem ledenjaka i ledenih ploha dolazi do globalnog porasta nivoa oceana, sto iznosti oko 20 cm od 1901. i taj porast se ubrzava.Uoceno je usporavanje porasta glob. temp. od 1998. Ima vise razloga za to usporavanje trenda, 1 je toplinski efekt El-Nina oko 1998., kao i prirodna varijabilnost te toplina apsorbirana u gornje oceane.*http://www.whitehouse.gov/photos-and-video/video/2014/01/08/polar-vortex-explained-2-minutes*Climate collective state (average, std. dev., extremes,..) of atmospheric & (sub-)surface parameters over a certain region and time, e.g., 30 yr.Climate Change systematic departure from a mean climate state, i.e., a trend in collective state of atmos. & (sub-)surface parameters over a certain region compared to the basic climate state, e.g., the climate in 1961-1990.*-THE OBS. GIVE THE CURRENT STATE AN INCOMPLETE PICTURE; THEN THE NWP &/or CLIMATE MODELS MAY PROCESS THE OBS. -> A FULLER PICTURE.-ATMOS. VARIABILITY: almost all of the variability comes from a background continuum of timescales, not from a finite number of periodic undulations!*RESOLVED vs. UNRESOLVED (PARAMETERIZED) PROCESSES- TU SPADAJU: ZRACENJE (RADIJACIJA), MOKRI PROCESI (OBLACI, OBORINA, SNIJEG, LED, PRIPADNI POD-TIPOVI) I TURBULENCIJA (U OBZIR SE UZIMAJU SAMO VERTIKALNI TURB. TRANSPORTI PROGN. VELICINA I TO SE NAJCESCE TRETIRA KAO BRZA, TJ. TURBULENTNA VERTIKALNA DIFUZIJA)2 GL. IZVORA POGRESAKA U METEOROL. SIMULACIJAMA: NEODREDJENOST U 1] POCETNIM I RUBNIM UVJETIMA, 2] MODEL (PRETPOSTAVKE, NUMERIKA, PARAMETRIZACIJE). ZA KLIM. MODELE/SIMULATORE 1. JE MANJE VAZNO (JER JE IONAKO IZGLADJENO, TJ. DOVOLJNO USREDNJENO U PROSTORU I VREMENU), ALI JE ZATO 2. IZUZETNO VAZNO!- LINEARNI RAST NA SLICI ~ = DO Forecast timeESSENTIALLY THE SAME, BUT Oceans, soil & ice treated differently (for the NWP e.g. just prescribe & linearly extend it from climatology & obs. no feedbacks) Surface & biosphere treated differently (for the NWP e.g. just prescribe it, i.e., again no feedbacks)- Weather forecasting is usually treated as an initial value problemclimatology deals primarily with a boundary condition problem and the patterns and climate devolving there from

*2nd from 2 most important slides (1st one is with last milenia obs. & clim. Projections to the end of 21st cent.)*The climate reference is that from 1961 through 1990. 3 Global & 1 Regional model (RegCM, forced by EH5OM) are compared all give warming. All results are for A2 scenario (A2 = 2nd most extreme scenario; A1 = business as usual).

Brankovi ., Srnec L., Patari M. 2010: An assessment of global and regional climate change based on the EH5OM climate model ensemble. Climatic Change 98, 21-49.*RegCM results: the difference between the future (P1) & reference (P0) climate for (1961 through 1990 yr.), i.e., (2011 2040) yr. = P1 P0. => General summertime warming & less cold wintertime nights.

Brankovi ., Patari, M., Gttler I., Srnec L. 2012: Near-future climate change over Europe with focus on Croatia in an ensemble of regional climate model simulations. Climate Research, 52, 227-251. http://www.int-res.com/articles/cr_oa/c052p227.pdf

*Ever improving numerical resolution in our simulators. -Still, refined parameterizations will be needed!3 different regimes: Weather Macro-weather =(low freq. weather) Climate.SOMETHING TO GET MORE CONCERNED ABOUT & BETTER DEFINE FUTURE PROJECTS & ACTIONS (IN ACCORDANCE WITH MITIGATIONS OF NEGATIVE EFFECTS OF CLIMATE CHANGE) To mention prof. TONCI MATULIC (bio-ethics) at 3rd arrowVJERODOSTOJNOST, DOSLJEDNOST!Olga Carevic, Drazen Vikic-Topic: znanost + humanizam!OFFER THE MAIN REFERENCES VIA EMAIL, ETC. RELATE AGAIN TO THE MAIN INSTITUTIONSAs the former but for precipitation (A2, etc.). There are more complex fields: dipole structures (NW more, S less precipitation), RegCM give more granular-like smaller-scale features in its precipitation estimates.*