The insane temperature rise of our planet

The insane temperature rise of our planet

Climate change is an issue that is not yet capturing the public opinion as it should do. One of the reasons is that the year-be-year temperature variations, at global scale, are much smaller than day-by-day variations at local scale, or seasonal variations at global or local scale. However, there is a certain parallelism between the body temperature of a person and the climate. If one records its body temperature every minute of a day, he will discover some daily variations, which could vary little less than 1 °C. Also, different persons can have different mean body temperatures, with values spanned over 1 °C or sligthly more, depending on each personal condition. An athlete immediately after a competition, or a normal person after a stressing exercise, can have a body temperature even 1°c or more superior to its normal mean. Well, these normal variations represent the “weather” of the person, and do not indicate necessarily the presence of a pathology.

However, if the temperature of a certain person start rising, more or less regularly, in the time, this variation represents a sort of “climate” of the person, with is changing, and may be a symptom of something not necessarily good for the health of the person. This is true even if such “climate” variation could be smaller than those that we have previously called “weather” variations. The scientific problem is thus to distinguish normal variations from abnormal variations, differentiating the scales. While the communication problem is how to inform in a correct but clear way the people about such dynamics.

We have now the fortune of having available more than one century of meteorological observations, carried out in several meteorological stations displaced in various places in the Earth. Several climatic centers have collected a subset of these data and have performed some analyses on such data, in order to exclude anomalous trends or data. And have calculated an estimate of the global mean temperature. Since the choice of stations and the treatment of data has been different from centre to centre, there are some differences among the datasets, but the emerging signal is univoque and incontestable: global mean temperature is increasing.

Furthermore, several climatic models (that, more properly, are now called Earth System Models) have been run by different teams to simulate the future climate of the Earth. Despite each individual model tends to give a particular answer, the current method to consider such kind of projections is to consider the ensemble of the results of a wide set of models. This has been performed, for instance, during the experiment CMIP5, whose preliminary results have constituted the core of the findings of the last IPCC report.

With Stefano Caserini, coordinator of Italian blog climalteranti.it, we have had the idea of combining the two informations, data and models, in a visual way. We have chosen as dataset the GISS and as model the CMIP5 ensembles, by selecting three different scenarios adopted: the RCP 2.6, the RCP 4.5, and the most extreme RCP 8.5, respectively corresponding to low, medium, and high emissions. In particular, RCP 8.5 scenario outlines what we would expect if the emissions will continue to change as they did until now (i.e. with a continuous increment).

Monthly climate change - GISS + RCP 8.5

Evolution of monthly mean temperature anomalies from 1880 to 2100, referred to the period 1880-1909. the observations relative to the period January 1880 – April 2016 are extraxted from dataset GISS, while the simulation data, relative to the period 2017-2100, have been gathered from the ensemble values of experiment CMIP5, in this case selecting the extreme high-emissions scenario RCP 8.5.

This is instead the case of the milder scenario RCP 2.6:

GISS + RCP 2.6

Evolution of monthly mean temperature anomalies from 1880 to 2100, referred to the period 1880-1909. the observations relative to the period January 1880 – April 2016 are extraxted from dataset GISS, while the simulation data, relative to the period 2017-2100, have been gathered from the ensemble values of experiment CMIP5, in this case selecting the low-emissions scenario RCP 2.6.

while this is the animation of the intermediate scenario RCP 4.5:

GISS + RCP 4.5

Evolution of monthly mean temperature anomalies from 1880 to 2100, referred to the period 1880-1909. the observations relative to the period January 1880 – April 2016 are extraxted from dataset GISS, while the simulation data, relative to the period 2017-2100, have been gathered from the ensemble values of experiment CMIP5, in this case selecting one of the intermediate scenarios, i.e. the medium-emissions RCP 4.5 .

Model simulations data are available in the period 1860-2100, while GISS observations refer to the period 1880-2016 (last datum is April). I have merged those two datasets by evaluating in each case the respectively anomaly in the common period 1880-1909 (a 30-year period, as usually it is done in climate analyses).

I have visualized the result with two different methods. I have used the spiral method of monthly anomalies, originally developed by Ed Hawkins for HadCRUT data, and I have considered the linear plot of montly anomalies, as done by myself in a recent post with HadCRUT data.

The first method is discussed in detail in this post of climalteranti.it, thus here I will describe the second, adding some short general considerations (short because I believe that these plots can talk by themselves).

These are, in my opinion, two different but impactive ways to visualize the climate change which is going on. The animations start from 1880 and, month by month, show the temperature variations up to April 2016. It is evident the initial cooling in the first decade of 1900, the warming between 1920 and 1930, the stationariety in the decade of the WWII, another weak warming immediately after, then a stasis between 1960 and 1970, and then rapid increase of warming rate since 1980, with last fifteen years able to update at least one montly record almost every year. Until the anomalous period of last nine months, which places completely out of the above range.

Future climate simulations by CMIP5 scenarios show a continuous warming, almost similar for all three scenarios up to 2030, then rapidly differentiating. Note that warming rate of models is more regular, due to the fact that these data represent an ensemble and are not just the output of a single model. The anomalous warmest records established from January to April 2016 seems to be updated around 2025-2030, when those values would become the regular climate. Then, after 2030, different scenarios start to differentiate from each other, with just the common result to show a larger anomaly in winter. At the end of this century, even in the low emissions scenario (RCP 2.6), a season like the last one will be regarded as a cool period. But, if we look at the most extreme scenario (RCP 8.5, corresponding to high emissions), it will be regarded as a sort of mini-ice age…

The scenarios begin to differentiate from about 2030… there is still a few time for trying to make occurring the mild scenario RCP 2.6 instead of the extreme RCP 8.5 one… not too much time, because greenhouse gases increases inexorably, and consequent global warming too.

We can choose… we must choose!

La temperatura malata del nostro pianeta

La temperatura malata del nostro pianeta

Il cambiamento climatico è una tematica che non cattura ancora l’opinione pubblica come dovrebbe. Una ragione è che le fluttuazioni termiche annue, a scala globale, sono molto più piccole delle variazioni diurne a piccoal scala, o di quelle stagionali a scala locale o globale. Tuttavia, si può notare un certo parallelismo tra la temperatura corporea di una persona e il clima. Se uno monitorasse la propria temperatura corporea in ogni minuto del giorno, noterebbe alcune variazioni diurne di poco meno di 1 °C. Inoltre, persone diverse possono avere temperature corporee diverse, anche in questo caso con variazioni di 1 °C o più, anche in funzione delle proprie condizioni personali. Un atleta, immediatamente dopo una gara, o una persona normale dopo un esercizio stressante, possono avere una temperatura corporea superiore anche di 1 °C rispetto alla norma. Bene, queste variazioni normali rappresentano il “tempo meteorologico” di una persona, e non indicano necessariamente la presenza di qualche malattia.

Tuttavia, se la temperatura di qualcuno inizia ad aumentare, più o meno regolarmente, nel tempo, questa variazione rappresenta una sorta di “clima” di una persona, che sta cambiando, e può essere il sintomo di qualcosa non necessariamente positivo per la salute della persona. Questo è vero anche se queste variazioni “climatiche” sono inferiori a quelle che in precedenza abbiamo chiamato variazioni del “tempo meteorologico”. Il problema scientifico è quindi distinguere le variazioni normali da quelle anormali, differenziandone le scale. Mentre il problema comunicativo è come informare l’opinione pubblica, in modo corretto ma comprensibile, riguardo a queste dinamiche.

Abbiamo la fortuna di avere a disposizione oltre un secolo di osservazioni meteorologiche, eseguite in diverse stazioni dislocate in varie località della Terra. Molti centi climatici hanno raccolto dei sottoinsiemi di questi dati e li hanno analizati, in maniera da eliminare i trend o i dati anomali. E hanno calcolato una stima della temperatura media globale. Poiché la scelta delle stazioni ed il trattamento dei dati è stato differente da centro a centro, ci sono alcune differenze tra i vari dataset, anche se il segnale che emerge è abbastanza univoco e incontestabile: la temperatura media globale sta aumentando.

Inoltre, diversi modelli climatici (ora si chiamano più propriamente Earth System Models, cioè modelli del sistema terrestre) sono stati fatti girare da vari gruppi di ricerca per simulare il clima terrestre futuro. Anche se ogni modello tende a fornire una risposta particolare, oggi si preferisce guardare a questo tipo di proiezioni considerando l’insieme de irisultati di un ampio gruppo di modelli. Questo è stato fatto, ad esempio, nel corso dell’esperimento CMIP5, i cui risultati preliminari hanno costituito il nucleo delle affermazioni riportate sull’ultimo rapporto IPCC.

Con Stefano Caserini, coordinatore di climalteranti.it, abbiamo avuto l’idea di combinare le due informazioni, dati e proiezioni modellistiche, in modo visuale. Abbiamo scelto come dataset quello del GISS, e come dati modellistici gli insiemi dell’esperimento CMIP5, selezionando tre diversi scenari: RCP 2.6, RCP 4.5 e il più estremo RCP 8.5, corrispondenti rispettivamente ad emissioni basse, medie e alte. In particolare, lo scenario RCP 8.5 corrisponde a quello che ci si aspetteremmo che succedesse nel caso in cui le emissioni proseguissero a variare come hanno fatto finora (cioè con un continuo incremento):

Monthly climate change - GISS + RCP 8.5

Evolution of monthly mean temperature anomalies from 1880 to 2100, referred to the period 1880-1909. the observations relative to the period January 1880 – April 2016 are extraxted from dataset GISS, while the simulation data, relative to the period 2017-2100, have been gathered from the ensemble values of experiment CMIP5, in this case selecting the extreme high-emissions scenario RCP 8.5.

Qui vediamo invece la situazione che ci aspettiamo secondo lo scenario “migliore”: RCP 2.6:

Monthly climate change - GISS + RCP 2.6

Evolution of monthly mean temperature anomalies from 1880 to 2100, referred to the period 1880-1909. the observations relative to the period January 1880 – April 2016 are extraxted from dataset GISS, while the simulation data, relative to the period 2017-2100, have been gathered from the ensemble values of experiment CMIP5, in this case selecting the low-emissions scenario RCP 2.6.

mentre qui è presentato qullo intermedio RCP 4.5:

Monthly climate change - GISS + RCP 4.5

Evolution of monthly mean temperature anomalies from 1880 to 2100, referred to the period 1880-1909. the observations relative to the period January 1880 – April 2016 are extraxted from dataset GISS, while the simulation data, relative to the period 2017-2100, have been gathered from the ensemble values of experiment CMIP5, in this case selecting one of the intermediate scenarios, i.e. the medium-emissions RCP 4.5 .

Le simulazioni modellistiche sono disponibili nel periodo 1860-2100, mentre le osservazioni GISS si riferiscono al periodo 1880-2016 (l’ultimo dato è quello di aprile). Ho integrato i due dataset calcolando per ognuno la rispettiva anomalia (differenza rispetto alla media) nel periodo comune 1880-1909 (un trentennio, come di solito si fa nelle analisi climatiche).

La visualizzazione del risultato l’ho fatta in due modi diversi. Ho usato il metodo a spirale delle anomalie mensili, sviluppato orinariamente da Ed Hawkins per i dati HadCRUT, ed ho anche mostrato un grafico lineare delle anomalie mensili, come avevo fatto in un post recente per visualizzare i dati HadCRUT. Il primo dei due metodi è visualizzato in dettaglio in questo post su climalteranti.it, per cui qui di seguito descriverò il secondo e farò alcune brevi considerazioni generali (brevi perché ritengo che i grafici parlino da soli).

Si tratta di due metodi diversi ma efficaci per visualizzare il cambiamento climatico in corso e quello che ci attende. Le animazioni iniziano dal 1880 e, mese per mese, mostrano le variazioni di temperatura fino ad aprile 2016. Si vede bene il raffreddamento nel primo decennio del 1900, il riscaldamento tra il 1920 e il 1930, la stazionarietà nel decennio della seconda guerra mondiale, il successivo piccolo riscaldamento, la nuova stasi tra il 1960 ed il 1970, e poi il rapido incremento del rateo di riscaldamento a partire dal 1980, con gli ultimi quindici anni in grado di aggiornare almeno un record mensile praticamente ogni anno. Fino ad arrivare al periodo anomalo degli

ultimi nove mesi, che si colloca totalmente al di fuori dal range dei valori precedenti.

Le simulazioni climatiche future degli scenari CMIP5 mostrano un continuo riscaldamento, praticamente analogo per i tre scenari fino al 2030, dopodiche gli scenari si differenziano nettamente tra loro. Notiamo anche che il rateo di riscaldamento fornito dai modelli è più regolare, grazie al fatto che questi dati sono rappresentativi di un insieme e non il risultato di un modello singolo. I valori anomali registrati nel quadrimentre gennaio-aprile 2016 sembrano rientrare nelle medie intorno al 2025-2030, quando saranno rappresentativi del “clima normale” di quegli anni.

Dopo il 2030, come si diceva, gli scenari si differenziano rapidamente, con l’unico risultato comune di un riscaldamento più sensibile d’inverno. A fine secolo, anche secondo lo scenario di basse emissioni (RCP 2.6), una stagione come l’ultima trascorsa apparirà come un periodo freddo. Ma, se si guarda lo scenario più estremo (RCP 8.5, che corrisponde alle emissioni alte), apparirà quasi come una sorta di mini-era glaciale…

Gli scenari iniziano a differenziarsi intorno al 2030… c’è ancora un briciolo di tempo per cercare di far verificare lo scenario sopportabile RCP 2.6 invece di quello estremo RCP 8.5… non tanto tempo, perchè i gas serra aumentano inesorabilmente, e il conseguente riscaldamento globale anche.

Possiamo scegliere… dobbiamo scegliere!

Sulle calorie, sull’energia e sul risparmio energetico

Sulle calorie, sull’energia e sul risparmio energetico

Oggi il mio post cambia un po’ discorso rispetto alla tematica del blog. Infatti parlerò di calorie. Traggo ispirazione dal fatto che, nell’università coreana in cui mi trovo in questo momento (la Ewha Womans University – rimando chi volesse approfondire il motivo della presenza di scuole femminili in Corea a questo mio articolo di qualche tempo fa), hanno tentato di invogliare la gente a far le scale (invece dell’ascensore – ma l’iniziativa non pare riscuotere molto successo…) appiccicando sugli scalini l’indicazione delle calorie consumate ogni due gradini, nonché dei secondi di vita risparmiati. Apparentemente si perdono 0,3 calorie ogni due gradini saliti, o meglio 0,3 Cal, che in realtà sono le grandi calorie, quelle usate in scienza della nutrizione, che comunemente si chiamano calorie. Il numero torna con quanto viene indicato su alcuni siti popolari in cui si parla di calorie e nutrizione, come ad esempio questo sito, dove si dice che salire le scale richiede circa 8÷11 calorie al minuto. Beh, nell’ipotesi, non così campata per aria, di salire un gradino al secondo, questo significa un consumo calorico di 0,13÷0,18 calorie al gradino, numero che è in linea con l’indicazione sui gradini dell’università Ewha. Ma è un numero che, in realtà, non ci dice molto, di per sé. Sembra soltanto molto piccolo, e forse è per questo motivo che “non tira”. Ma è davvero piccolo?

2016-03-07 10.03.40

Fig. 1 – dettaglio di una rampa di scale dell’istituto che ospita il Dipartimento di Atmospheric Sciences and Engineering presso la Ewha Womans University, Seoul, Corea.

Proviamo a fare alcuni “conti della serva”. L’altezza media di un gradino varia tra 10 e 15 cm. Se una persona di 70 kg sale verticalmente di un metro, deve spendere energia per vincere la forza di gravità. Tale energia equivale all’energia potenziale gravitazionale, ed è data da E=mgh dove m è la massa della persona (70 kg, abbiamo detto), g l’accelerazione di gravità (9,81 m s-2) e h lo spostamento in verticale (diciamo 10 cm, ovvero 0,1 m). Si ottiene E=68,67 J. E siccome 1 J = 0,239 cal = 2,39 10-4 Cal, questo significa circa 0,016 Cal a gradino. Cioé circa un decimo rispetto al valore indicato… ma questa è solo l’energia spesa per salire… l’energia spesa da un essere umano non si limita alla sola energia contro la forza di gravità. Il dispendio energetico complessivo, stando in piedi inattivi, è quantificato in 1,0 Cal/min (ovvero 0,016 Cal/s) mentre, se si cammina, tale dispendio è circa tre volte maggiore (2,5÷3,5 Cal/min camminando in piano a 4 km/h, pari a circa 0,042÷0,058 Cal/s). Pertanto, se si considera che una persona salga un gradino al secondo, ecco che al lavoro fisico fatto contro la gravità vanno già sommati il consumo di una persona inattiva e il consumo nel camminare in piano (camminare in salita equivale a camminare in piano più lo spostamento verticale), ovvero si arriva in media a circa 0,08 Cal al gradino, che è circa metà del valore indicato. Poi, naturalmente, ci sono altri aspetti da considerare, ma intanto vediamo che l’ordine di grandezza del dato pare sensato.

bressanini_scienze

Fig. 2 – Articolo “Il destino del grasso” pubblicato nella sezione “Pentole e provette” del numero di Marzo 2016 de Le Scienze.

Vediamo di approfondire ancor più il discorso: in questo, prendo ispirazione anche dal magistrale articolo di Dario Bressanini uscito sul penultimo numero de Le Scienze, e dai consumi riportati su quest’altro sito, che è molto ricco di spunti. Qui il consumo energetico richiesto per salire le scale è quantificato in 12,8 cal/min, a cui viene aggiunto il dato di 6 cal/min per la discesa dalle scale. Tali dati sono riferiti ad una persona di 70 kg, e – sempre nell’ipotesi di salire o scendere un gradino al secondo, possono rispettivamente tradursi in 0,21 e 0,10 Cal per scalino salito/sceso. Essi risultano un po’ maggiori rispetto ai dati appiccicati agli scalini dell’università Ewha, ma occorre notare che essi sono riferiti ad una persona con normopeso di 70 kg, mentre presumibilmente le studentesse dell’università della Ewha sono più vicine ai 50 kg: in tal caso le cifre cambiano rispettivamente in 9,2 Cal/min per salire le scale e 4,3 Cal/min per scenderle, pari rispettivamente a 0,15 e 0,07 Cal per scalino, e il primo dei due valori è esattamente il valore riportato sugli scalini.

Sono valori piccoli? Effettivamente lo sembrano… ma in realtà non è così! Infatti, lo stesso sito permette il paragone con molte altre attività fisiche, e si può scoprire che, grossolanamente, il rateo di consumo energetico nel salire le scale è in realtà ragguardevole e del tutto paragonabile a quello relativo ad una partita di calcio o di rugby, nell’unità di tempo: salire le scale è infatti un’attività energeticamente molto dispendiosa, solo che, ovviamente, non è pensabile di farlo per la durata di un’intera partita di calcio: 90 minuti…

In ogni caso, i numeri di cui sopra possono permettere una rapida conversione dell’energia in gradini di scale da fare, o volendo in piani, se si ipotizza che un piano sia composto da trenta gradini da 10 cm. E, quindi, può essere interessante paragonare tali valori a quelli delle riserve energetiche immagazzinate nel nostro corpo, o a quelli degli alimenti che mangiamo. Perché esprimere le calorie in gradini da salire ci può aiutare a quantificare.

Il cibo italiano è notoriamente ricco di carboidrati. Ebbene, 1 g di carboidrati equivale a 3,8 Cal. Quindi, la razione di 60 g di pasta (senza sugo) da sola contiene un minimo di 228 Cal, ed equivale a 1550 gradini da salire (per un individuo di 50 kg), o 51 piani. In realtà, poiché poi bisogna pure scendere, si può usare il dato di 0,15+0,07=0,22 Cal/gradino, comprensivo di salita e discesa, e l’equivalenza sarebbe con soli 1036 gradini, ovvero 34 piani. Naturalmente un individuo di 70 kg consuma di più e pertanto potrebbe permettersi di salire e scendere soltanto per 735 gradini, equivalenti a 25 piani.

Questo giochino si può ripetere abbastanza facilmente per diversi alimenti, e si ottiene la tabella in allegato, nella quale ho riportato alcuni alimenti di uso comune prendendo i dati relativi all’apporto calorico da questo sito. Vorrei soltanto sottolineare che non sto demonizzando il cibo di per sé: ogni persona necessita di un apporto calorico adeguato durante la giornata, che in genere viene quantificato tra le 2000 e le 2500 Cal, a seconda del sesso e dell’attività fisica, e quando tali valori non vengono raggiunti in modo sistematico e prolungato si va incontro alla denutrizione. Il mio scopo è far capire il valore calorico degli alimenti. E far capire che, se le calorie ingurgitate eccedono sistematicamente le soglie (“che sarà mai qualche caloria in più…“), il nostro corpo le accumula producendo lipidi cioé grassi, al rateo di 9 Cal per 1 g. Se uno accumula 1 kg, ad esempio, poi per smaltirlo, dovrà consumare 9000 Cal. Ovvero salire 60000 scalini, ovvero 2000 piani.

La tabella seguente riporta le equivalenze tra calorie, gradini e piani, nell’ipotesi di salire un gradino al secondo e che un piano contenga 30 gradini, per un uomo medio di 70 kg e una donna media di 50 kg, che definirei quindi in gran forma. Ho inserito alcuni alimenti di uso comune, e altri che rappresentano degli sfizi…

tabella

Tabella 1 – Contenuto calorico di porzioni standard di cibo, rapportate al numero di gradini da salire e scendere da parte di un individuo medio di 50 e 70 kg, e/o di piani.

mm_Big Tasty Bacon

Fig. 3 – Per smaltire le calorie di un panino come questo, occorre salire e scendere scale per l’equivalente di un centinaio di piani!

Che dire? Diciamo che alcuni sfizi “costano” molto, in termini di calorie. Non vuol dire che non ce li si può permettere, ma occorre esserne consapevoli in modo da poterli compensare riducendo le calorie nel resto della giornata o nel giorno successivo.

Ora, uno si potrebbe chiedere cosa c’entri tutto questo discorso sulle calorie e sui contenuti energetici del cibo con il clima. Il motivo è presto detto.

gelato

Fig. 4 – Immagine di un succulento e accattivante gelato sormontato da abbondante panna montata.

Da un lato, il nostro corpo richiede un determinato contenuto calorico giornaliero; ingurgitare più calorie del dovuto può magari appagare i sensi (a chi i sensi non andrebbero in subbuglio guardando – ad esempio – un bel gelato sormontato dalla panna montata, come quello in figura 4?), ma ha come risultato che, se l’operazione è ripetuta spesso, si ingrassa e conseguentemente si danneggia la propria salute; inoltre si richiede un maggiore (e inutile) quantitativo di cibo dall’ambiente, per produrre il quale serve un maggiore apporto energetico che, attualmente, in gran parte richiede l’uso dei combustibili fossili, e quindi produce gas serra. Infine, la tendenza all’obesità è poi collegata all’insorgenza di diverse malattie, che generalmente si manifestano più avanti negli anni, ma con un’età media della popolazione che ormai ha superato gli 80 anni diventa poi inevitabile doversi scontrare, prima o poi, con qualche patologia che rischia di diventare invalidante. Nel 1988 negli USA uscì il musical Hairspray, noto in Italia come “Grasso è bello“, poi trasformato in film ed interpretato, tra gli altri, da John Travolta e Michelle Pfeiffer. Beh, il film è certo divertente, ma il messaggio è fuorviante e sbagliato. Grasso potrà anche essere bello, de gustibus, ma sicuramente non fa bene né a se stessi, né all’ambiente. Limitare la nutrizione al quantitativo corretto è dunque una maniera salutare e magari indiretta ma molto utile anche per limitare le emissioni di gas serra, e quindi anche il cambiamento climatico in corso. Questo discorso vale in generale, e vale anche analizzando in particolare il costo energetico di produzione del cibo: non voglio qui parlare nel dettaglio di questo argomento, ma è noto, ad esempio, che la carne bovina ha un altissimo costo produttivo in termini di emissioni, ed un suo consumo eccessivo danneggia la salute in vari modi.

Hairspray

Fig. 5 – La locandina del film Hairspray.

Dall’altro lato, svolgere quitidianamente attività fisica aiuta la salute del nostro corpo e, di nuovo, contribuisce a limitare il dispendio energetico. Ad esempio, si pensi, in un palazzo di pochi piani, all’ipotesi di salire e scendere i piani a piedi usando le scale rispetto ad utilizzare l’ascensore. Da un lato ci sono i benefici sulla salute: l’attività fisica quotidiana richiesta per il nostro benessere, la diminuzione del rischio di mortalità durante la salita, il consumo energetico, la maggiore forma fisica e capacità aerobica, la perdita di peso, il potenziamento muscolare, il miglioramento della quantità di colesterolo “buono” presente nel sangue, solo per citare i più comuni. Dall’altro, uno può farsi un’idea del consumo energetico di un ascensore leggendosi questo interessante e corposo documento, in cui sono prese in considerazione diverse tipologie di ascensori, e dove si può notare come una buona parte del consumo sarebbe abbattibile con l’installazione di ascensori di nuova concezione.

Riassumendo: fare attenzione a ciò che si mangia ed all’apporto calorico del cibo, e fare attività fisica ci fa rimanere in salute e ci permette anche di limitare (un po’) le emissioni di gas serra che alterano il nostro clima. Perché dunque non farlo?

Quel fatidico 17 aprile di ventiquattro anni fa in Piemonte…

Quel fatidico 17 aprile di ventiquattro anni fa in Piemonte…

Questa volta voglio condividere un ricordo personale del tutto particolare, relativo ad un giorno di ventiquattro anni fa che non ho più dimenticato: il 17 aprile 1991. Che non cadeva neppure di venerdì, come quest’anno, ma di mercoledì. Eppure…
Il 1991 è ricordato come l’anno dell’eruzione del Pinatubo, praticamente una delle ultime maggiori eruzioni vulcaniche che influirono, sia pure in minima parte, sull’andamento della temperatura media globale. Ad aprile avvenne anche la tragedia della Moby Prince. Ma il 17 ed il 18 sono ricordati per la neve in pianura, praticamente in tutto il nord Italia.
All’epoca il nostro Dipartimento (di Fisica Generale, Università di Torino) aveva una stazione di misura a Trino Vercellese, sulla torre di 120 metri costruita a fianco della centrale nucleare mai partita, come era prevista dalla legge per il monitoraggio atmosferico nei pressi delle centrali nucleari. Intorno alla torre, presso alcuni cascinali attigui, alcuni colleghi avevano dislocato delle piccole postazioni con degli strumenti (microbarometri e strumenti vari). Io ero dottorando in Geofisica del consorzio interuniversitario Genova-Torino-Modena. Nell’aprile 1991 decidemmo di fare una visita al laboratorio di Trino ed anche a tutte le stazioni vicine, portando anche con noi un laureando che aveva lavorato per quasi un anno sui dati di Trino, tanto per fargli vedere il sito che era stato oggetto della sua tesi.
Già allora, pur non essendoci previsioni dettagliate come oggi, le incursioni di aria fredda da est erano previste meglio di altri fenomeni, per cui già da qualche giorno si parlava di quell’avvezione; ricordo che sconsigliai la visita in tale giorno. Non arrivai a prevedere la neve, ma che avrebbe fatto un bel temporalone con magari grandine molle, graupel e tanto vento me lo aspettavo. Purtroppo, le logiche degli incroci del tempo libero di tutti non ci diedero altra scelta.
Partimmo dunque di prima mattina in cinque: io vestito in pratica da inverno, gli altri meno. Prima di partire, ricordo che consultai il numero telefonico 1911, che all’epoca era praticamente l’unico mezzo per sapere qualche valore meteo in giro per l’Italia, e sentìi che, nel nordest, faceva parecchio freddo, con temperature già sui 3-4°C. A Torino, invece, cielo sereno e temperature da inizio estate. Quando mi videro, vestito col giaccone pesante e gli scarponi, qualcuno dei colleghi mi prese bonariamente in giro… Io continuavo a ripetere: guardate che arriva, in Veneto fa già freddo. Ma quel cielo azzurro e quel caldo sembravano volermi sfottere…
Passammo la mattinata a fare le misure del caso. Ogni tanto qualcuno dei presenti alzava la testa, guardava il cielo azzurrissimo e terso, si detergeva il sudore, e mi guardava soltanto… o diceva “ma il tuo fronte freddo dov’è?” Verso mezzogiorno, c’erano 18°C, una leggerissima brezza, ed un cielo che lasciava presagire solo altro caldo…
Poi… alle 12 circa, cominciammo a sentire un venticello un pochino più teso. Alzammo la testa e, all’orizzonte verso est, scorgemmo dei nuvoloni scuri; contemporaneamente cominciammo a sentire un sommesso brontolio in distanza. In quel momento, pur non avendo mai sperimentato prima un fenomeno simile dal vivo, sentìi che la previsione era stata corretta: il fronte stava arrivando! Nel giro di qualche minuto, fummo raggiunti dal temporale prefrontale, che si manifestò con raffiche fortissime di vento, tuoni e lampi, pioggia orizzontale. Ora i sudori erano non più di fatica, ma di timore…
Avemmo appena il tempo di riparare nell’attiguo laboratorio, ai piedi della torre. Lì c’era il sistema di acquisizione con display che raccoglieva e visualizzava i dati in tempo reale, e ricordo di aver visto la temperatura letteralmente precipitare, con l’impressionante ed insostenibile rateo di circa 0,1 °C ogni dieci secondi.
Mi resi conto che stavo osservando un evento raro, uno di quelli che, per un appassionato di meteorologia quale ero e sono tuttora, si ricordano poi per tutta la vita.
Decidemmo, su mio consiglio, di andare a mangiare, vista l’ora, e visto che il fenomeno non prometteva di durare così poco. Nessuno ora mi diceva più nulla, e soprattutto nessuno mi prendeva più in giro. Nell’aria, c’era la sensazione che stava succedendo qualcosa di particolare. All’uscita dal pranzo, fummo accolti da ventate gelide: eravamo passati – come temperature – da valori tipici di inizio estate al tardo autunno. Il vento era ancora fortissimo, la temperatura era scesa sotto i 10°C, tuoni e fulmini a tutto andare. Recuperammo i pc lasciati in mattinata negli appositi alloggiamenti delle stazioncine, con non poca fatica, visto il vento e la pioggia sferzante. La portina di uno dei boxini venne divelta dal vento all’atto dell’apertura: nonostante la tenessimo, ci scappò di mano, e dovemmo rincorrerla per i campi: una scena veramente da Paperissima. Più tardi, nei pressi di un’altra cascina, all’atto di aprire una portiera della macchina, la portiera stessa venne spalancata da una raffica di vento improvvisa e si incrinò leggermente, tanto che si richiuse a fatica. Ovviamente tutti coloro che non si erano vestiti in modo adeguato (ovvero sia il laureando che gli altri miei colleghi) si ritrovarono bagnati come dei pulcini. In quel frangente, non nego che guadagnai un’enorme considerazione come previsore meteorologo, visto che avevo avvisato tutti da tempo che quel giorno non era proprio adeguato per una missione in campo…
Alla fine, dopo aver fatto tutto quanto si poteva ancora fare nonostante il maltempo, tornammo in macchina; col  riscaldamento acceso al massimo come se fosse inverno, anche per evitare che i colleghi si ammalassero (io invece ero tranquillo…), e via verso Torino. La temperatura nel frattempo era scesa ancora, indicativamente sui 4-5 °C: adesso, a 24 anni di distanza, devo dire che non ricordo i valori esatti, e comunque non avevamo i termometri addosso, né c’erano le app che si collegavano in internet per farci vedere i valori. Non c’erano neppure i siti di meteobufale: che bei tempi! Per dirla tutta, non c’erano neppure i telefonini. Sì, avete capito bene: per chiamare gli altri, si usavano i telefoni a gettone (!); solo i miliardari avevano le auto col telefono dentro; e dico miliardari perché, all’epoca, non c’era l’euro ma la lira; c’era il MEC invede della UE, e la moneta unica esisteva solo come valore fittizio, e si chiamava ECU. Altri tempi, è vero; ma sono ancora vivo e neppure così vecchio!!!
Nel tragitto verso Torino, cominciammo a veder cadere, nell’incredulità generale, i primi fiocchi di neve e, procedendo verso Chivasso, la precipitazione divenne totalmente nevosa, con accumulo al suolo. Inconcepibile, visto che era il 17 aprile. E anche se – ventiquattro anni fa – il global warming non aveva ancora scaldato per bene il nostro pianeta come oggi, anche perché i valori di CO2 erano nettamente inferiori (eravamo sui 351 ppm… oggi ahimé abbiamo superato i 400!!!), veder nevicare in pianura a metà aprile era un vero shock!

Torino il 17 aprile 1991.

Torino il 18 aprile 1991.

In giro, poi, si vedevano scene veramente comiche, imbarazzanti, da ridere: gente intirizzita e senza ombrello (ma anche se ce l’avevano, era inutilizzabile, a causa del vento), alcuni addirittura in pantaloncini e maniche corte, tutti a piedi o in bici sotto la neve, i cui fiocchi saettavano in orizzontale. Anche in città stava nevicando: una cosa rarissima vedere la neve cadere a tormenta nel centro di Torino! Anche d’inverno.
Più tardi, tornando a casa (abitavo a Baldissero Torinese, dietro Superga), scoprìi che la strada per Superga era stata chiusa, come accadeva d’inverno, probabilmente perché qualcuno aveva provato a salire senza gomme da neve e si era bloccato; per cui dovetti fare il giro da Chieri.

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Il mio giardino a Baldissero Torinese, fotografato la mattina del 19 aprile, quando il fronte e il relativo minimo lasciarono il Piemonte.

Nei due giorni, 17 e 18 aprile, nel mio giardino (a poco meno di 500 metri di quota), misurai 24 cm di neve fresca. La nevicata continuò ancora per parte del 18 aprile, poi il fenomeno cessò. Ricordo che le temperature rimasero comunque fresche, per il periodo, fino ai primi di maggio.
Non farò l’analisi meteorologica, in quanto sul web se ne trovano già infinite. Ne cito qui una per tutte di meteoasti, e qui un altro link al forum di meteopassione. Ma voglio comunque dare qualche numero. Presso la mia stazione di Baldissero Torinese, il 17, la minima del mattino fu 9,2°C, la massima fu 17,8 °C, mentre alle ore 20 c’erano -0,3°C; il giorno dopo, minima di -0,3°C e massima di 3,5°C. Precipitazione: 5 cm di neve il 17, e 19 cm il 18; come pioggia e neve fusa, 12,9 mm il 17 e 25,4 mm il 18. A Torino Buon Pastore (stazione ARPA), il 17 minima 0,6°C e massima 16,7 °C; il 18 minima 0,8°c e massima 8,3°C; precipitazioni come pioggia e neve fusa: 41,2 mm nei due giorni.
Qui di seguito, gli articoli di giornale apparsi nelle varie edizioni provinciali de La Stampa: praticamente in ogni provincia il titolo è più o meno lo stesso, ed in quasi tutte le province piemontesi appare lo stesso articolo del giornalista Minetti che lamenta la mancata previsione della neve fino in pianura. In Liguria, invece, la cronaca non riporta tanto il maltempo o la neve, ma l’effetto del vento sull’allargamento dell’enorme chiazza di petrolio che l’affondamento della Moby Prince aveva rilasciato tra Mar Ligure e Tirreno il 10 aprile 1991, ovvero solo pochi giorni prima.

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An epochal-symbolic threshold: the CO2 concentration at Mauna Loa has exceeded 400 ppm!

It was in the air for days, and it has also created a certain expectation, with trepidation. Similarly as when we are awaiting the outcome of a surgery for a family member. But this event has nothing to rejoice. The question is very simple. At the Mauna Loa observatory, CO2 values ​​whose average over an entire day was greater than 400 ppm were recorded. One ppm means one part per million. That is to say, on a million of air molecules, 400 are CO2. It seems a small and harmless number. But it is not, unfortunately. Because these small quantities of gas are those that regulate the greenhouse effect on our planet. The greenhouse effect on Earth is responsible for the fact that the average global temperature, instead of being equal to a chilling value of -18°C, is approximately 15°C, a value much more livable for our species. And this happens thanks to the presence of a number of components, in the terrestrial atmosphere, which leave no escape throughout the infrared radiation that the Earth emits, but retain a certain part. It is a positive effect, then. More greenhouse gases there are in the Earth-atmosphere system, the more the greenhouse effect is big. Variations are small, almost imperceptible, few tenths of a degree, but accumulated can lead to large variations.

The greenhouse effect in short.

The greenhouse effect in short.

Few words on Mauna Loa observatory. Where is it? Here, on Hawaii islands.

An image of Mauna Loa Observatory.

An image of Mauna Loa Observatory.

Erected in 1956, the first CO2 measurements date 1958, thus it is the most ancient observatory measuring CO2 on Earth. Somebody criticizes the choice of the site as nearby there is the Kilauea volcano, whose emissions may affect the measurements. However, the observatory altitude is 3397m, and its elevation and location (in the middle of the Pacific ocean, away from major air pollution sources) make this site as an ideal place to sample the atmosphere. The high elevation of the observatory keeps also far away the lower local pollutants emitted below the observatory (such as also volcanic emissions), due to fact that it is quite higher than the strong marine temperature inversion layer present for most of the time in the region. An “a posteriori” demonstration of the quality of these data is the comparison of the CO2 trend of the Mauna Loa data (1.64 ppm per year) with the global trend (1.66 ppm per year), calculated considering the average of all remote stations in the world: they are statistically indistinguishable.

Global atmospheric CO2 (NOAA) versus Mauna Loa CO2 (NOAA). Credits: Skeptical Science.

Global atmospheric CO2 (NOAA) versus Mauna Loa CO2 (NOAA). Credits: Skeptical Science.

Let’s now came back to the original point. Yesterday, daily mean CO2 concentration has exceeded 400 ppm. It did not happen for about 3 million years. That means this has never happened since man lives on Earth. 400 ppm is a symbolic epochal threshold for the humanity..

The news is not yet official but, after the graph produced by NOAA (National Oceanic Atmospheric Administration), here reported (that on the link is regularly updated), the U.S. federal agency that deals with climate, the CBS has released yesterday a service confirming the measure.

Last year daily and weekly CO2 concentrations at Mauna Loa.

Last year daily and weekly CO2 concentrations at Mauna Loa.

It must be emphasized, once again, that the carbon dioxide enters the atmosphere as a result of the human use (and abuse) of fossil fuels: oil, gas, coal, methane, etc. Since we have started to use them (which means, since the Industrial Revolution, or even better, since the invention of the Watt machine), the history and prehistory of the human race have been accompanied by a carbon dioxide concentration lower than 300 ppm.

A preserved Watt beam engine at Loughborough University. Credits: wikipedia.

A preserved Watt beam engine at Loughborough University. Credits: Ashley Dace.

Still in the middle of the eighteenth century, it was equal to 280 ppm. Then, it started its apparently unstoppable growth till the actual values of 400 ppm.

CO2 in last 1200 years. Credits: IPCC AR4.

CO2 in last 1200 years. Credits: IPCC AR4.

Carbon dioxide, as well known, is the main greenhouse gas (GG). I like the description of the greenhouse effect given in this Italian blog: GGs trap the sun’s heat in the atmosphere, as a duvet traps heat in our body when we are in our bed during the winter. If there were no greenhouse gases, it would be like to sleep without duvet. But having too abundant greenhouse gas is like sleeping with two duvets. Nightmares and sweat are guaranteed…

We said that our Earth experienced for the last time an atmospheric concentration of carbon dioxide of 400 ppm about three millions years ago, i.e. before the appearance of the so-called Homo sapiens. At that time, the temperatures were 3-4°C higher than now, and the sea level was about 25 meters higher than now.

Reconstruction of the atmospheric concentration of CO2 in the last 65 million years: in the distant geological past, there have been periods when this greenhouse gas was vastly more abundant than today. For example, between the Paleocene and Eocene, around 50 to 55 million of years ago, it was about 2000 ppm. But this comparison cannot reassure about the current situation. At that time, indeed, the planet was completely different, with a different geology, climate and environment, and even some prehistoric human species existed. But today we live in a world more and more overcrowded, short of natural resources and plagued by numerous criticalnesses (environmental, demographic, social, economic and alimentary) that make humanity fragile in the face of abrupt climate change. During the Pliocene (between about 3 and 5 million years ago, red line), for the last time before today, a CO2 concentrations next to 400, sometimes 500 ppm was reached. Source: alpineanalytics.

Reconstruction of the atmospheric concentration of CO2 in the last 65 million years: in the distant geological past, there have been periods when this greenhouse gas was vastly more abundant than today. For example, between the Paleocene and Eocene, around 50 to 55 million of years ago, it was about 2000 ppm. But this comparison cannot reassure about the current situation. At that time, indeed, the planet was completely different, with a different geology, climate and environment, and even some prehistoric human species existed. But today we live in a world more and more overcrowded, short of natural resources and plagued by numerous criticalnesses (environmental, demographic, social, economic and alimentary) that make humanity fragile in the face of abrupt climate change. During the Pliocene (between about 3 and 5 million years ago, red line), for the last time before today, a CO2 concentrations next to 400, sometimes 500 ppm was reached. Source: alpineanalytics.com.

Reconstruction of the atmospheric concentration of CO2 in the last 65 million years: in the distant geological past, there have been periods when this greenhouse gas was vastly more abundant than today. For example, between the Paleocene and Eocene, around 50 to 55 million of years ago, it was about 2000 ppm. But this comparison cannot reassure about the current situation. At that time, indeed, the planet was completely different, with a different geology, climate and environment, and even some prehistoric human species existed. But today we live in a world more and more overcrowded, short of natural resources and plagued by numerous criticalnesses (environmental, demographic, social, economic and alimentary) that make humanity fragile in the face of abrupt climate change. During the Pliocene (between about 3 and 5 million years ago, red line), for the last time before today, a CO2 concentrations next to 400, sometimes 500 ppm was reached. Source: alpineanalytics.

Usually, CO2 concentration shows a marked annual cycle, due to the effect of the vegetation respiration: for this reason, the cycle is much more evident in the midlatitudes of the northern hemisphere, where the vegetation covers more extensively the Earth surface. Normally, during the first half of May, the carbon dioxide reaches the “peak” year: the concentration decreases after the forests of the northern hemisphere have completed the foliation. Thus, this year the epochal peak of 400 ppm has been exceeded almost at the end of the increasing period, and soon the mean value will come back below 400 ppm. But, year after year, the peak always grows.

A rough graphic simulation carried out by myself using the monthly (monthly, not daily: this is way the value is significantly lower than 400 ppm!) data measured at Mauna Loa (I have just graphically repeated the last year trend; yes, I know, very rough, but it gives the idea) shows that we have still two years in which we could see some values with daily or monthly values lower than 400 ppm. Then, after 2016, we will enter in a new era: the above 400 ppm CO2 era.

Monthly mean carbon dioxide concentrations measured at Mauna Loa (until April 2013) and hypothized for the next three years by continuing the last year trend. It is evident as September and October 2014 risk to be the last months with a CO2 monthly mean value below 400 ppm.

Monthly mean carbon dioxide concentrations measured at Mauna Loa (until April 2013) and hypothized for the next three years by continuing the last year trend. It is evident as September and October 2014 risk to be the last months with a CO2 monthly mean value below 400 ppm.

Monthly mean carbon dioxide concentrations measured at Mauna Loa (until April 2013) and hypothized for the next three years by continuing the last year trend. It is evident as September and October 2014 risk to be the last months with a CO2 monthly mean value below 400 ppm.

If you do not trust my rough projection, you may enjoy in watching this video, that shows the time history of atmospheric carbon dioxide from 800,000 years before present until January, 2012 (and it is possible to imagine how it will continue).

By the way, the video shows that, at high latitudes, the 400 ppm threshold has already been exceeded in some months several years ago. But here we are talking about Mauna Loa, Hawaii: which is located in an equatorial area and is representative of the world mean (remember the first figure).

And, as now people “old” like me is surprised by thinking that the first year university students had never experienced a world without mobile phone (and few year later we may repeat the same discussion for smartphones, facebook, twitter, …), some years later the young generation will be born in an above-400-ppm-CO2-era.

The effects of increased concentrations of greenhouse gases are not immediately evident. Until now, the planet’s average temperatures has increased only by 0.8°C with respect to before the Industrial Revolution, but already many people complain that no longer exist transition seasons and seasons are no longer those known in the past. The following video from NASA summarizes in 30 seconds how world temperatures have changed in the past 120 years.

The climate destabilization triggered by greenhouse gases that humans have released into the atmosphere also manifest in the increase of extreme weather events: heat or cold waves, drought and floods.

The cold spring in western Europe and a big portion of US, for example, is probably a side effect of the massive melting of Arctic ice which took place last summer. While talking of spring temperatures, let’s give a look on a global map. Here it is shown the map referring to the first two months of 2013 spring (we remember here that meteorologists count seasons starting from the first day of the month, so spring means March, April and May). I have decided to underline these data, as I am reading a lot of nonsense related to actual weather. The map reveals that there are some areas characterized by dark blue, which means cold. These areas (Canada, US and Europe) are densely populated by industrialized humans. There are also several areas characterized by quite large warm anomalies, but they concern some underpopulated, or not populated at all, areas of the planet. This is why we heard only about cold, and nothing about warm. We care only about what happens where we live. But climate do not make such distinctions, and from a climatological point of view, US and Antarctica are equal!

Anomaly of surface temperatures recorded during March and April, 2013, with respect to the period 1981-2010. A large cold area covers a big portion of North America and another one covers most of Europe, while central Asia, Africa, Greenland and both polar regions are experiencing unusually warm periods. Source: NCEP-NCAR.

Anomaly of surface temperatures recorded during March and April, 2013, with respect to the period 1981-2010. A large cold area covers a big portion of North America and another one covers most of Europe, while central Asia, Africa, Greenland and both polar regions are experiencing unusually warm periods. Source: NCEP-NCAR.

The temperature anomalies appear to be strongly connected with the corresponding anomalies of the geopotential pattern at 500 hPa.

Anomaly of 500 hPa geopotential height recorded during March and April, 2013, with respect to the period 1981-2010. Note the almost perfect coincidence between cold areas and areas with negative 500 hPa anomaly. Source: NCEP-NCAR.

Anomaly of 500 hPa geopotential height recorded during March and April, 2013, with respect to the period 1981-2010. Note the almost perfect coincidence between cold areas and areas with negative 500 hPa anomaly. Source: NCEP-NCAR.

A short look on the sea surface temperatures (SST) in the North Pole area reveals as there is a relevant positive anomaly of SST in the zone of the North Pole, which experienced on last September the largest ice-free extension. And it is impossible to think that these phenomena are not connected…

Anomaly of SST recorded during March and April, 2013, with respect to the period 1981-2010. Note the almost perfect coincidence between cold areas and areas with negative 500 hPa anomaly. Source: NCEP-NCAR.

Anomaly of SST recorded during March and April, 2013, with respect to the period 1981-2010. Note the almost perfect coincidence between cold areas and areas with negative 500 hPa anomaly. Source: NCEP-NCAR.

I will use less light (M’illumino di meno) – the Italian Energy Saving day

M’illumino di meno” is a symbolic initiative aimed at raising awareness on energy saving, and represents the most important communication campaign on energy saving in Italy.

The slogan of the day in this poster.

The slogan of the day in this poster: “the festivity of the energy saving”. I vote “I will use less light”.

It was launched in February 2005 by Caterpillar, a popular current radio show on the Radio2 channel of RAI (the Italian Public Broadcasting Service) which announced the First National Day of Energy Saving.

The conductors of the transmission Caterpillar as they appear in the web site of the transmission.

The conductors of the transmission Caterpillar as they appear in the web site of the show.

This year marks therefore the ninth edition of the initiative. The name given to the day is inspired by the famous verses of the hermetic poetry “Morning” (Mattina) by Giuseppe Ungaretti, 1970 Neustadt International Prize for the literature (poetry is composed of only two words: “M’illumino d’immenso”: in English, it may be translated, with more words, in “I flood myself with light of the immense).

An image of Giuseppe Ungaretti soldier.

An image of Giuseppe Ungaretti soldier.

The poetry "Mattina".

The poetry “Mattina”.

The day is organized every year around February 16. There is a reason for such choice: in fact, the February 16th, 2005, is the day when the Kyoto Protocol came into force, following the accession of Russia in November 2004. The day is not fixed because public holidays tend to be avoided. This year, the choice of the Energy Saving Day fell on Friday February 15th, and incidentally this is the day after the popular festivity of St. Valentine day. Here there is the hymn of the day (with Italian words), and in this site only the music.

Lighting on Europe.

Lighting on Europe.

Lighting on Italy.

Lighting on Italy.

The philosophy of “M’illumino di meno” is to convince more people as possible to limit the energy consumption, back saving the biggest energy deposit available in a free way and in a short time, and has been evidenced also by several blogs and social networks. Even if there are also other initiatives connected with the day, the maximum visibility on medias and the largest participation by common people are concentrated on the Energy Saving Day, i.e. in the 15th of February 2013: in that occasion, everybody is asked for reducing at the minimum their own private energy uses during the show time, from 6pm to 7.30pm.

Citizens ,companies, shop-owners, schools, restaurants, gyms and any other kind of association will be participating in their own personal way; turning off shop-windows, computers or electronic machines in laboratories, organizing candlelight dinners and so on.

Candlelight diner.

Candlelight diner.

Initially directed only to citizens, the initiative it was met with great success and gradually went widening, involving first, at the local level, individual municipalities, then the ANCI (Association of Italian Municipalities) and subsequently also the Presidence of the Council of Ministers, earning also the patronage of the Ministry of Environment.

The most incredible effect is assured by the symbolic turning off of the most important monuments and the most important city plazas, united in a sort of  “energy silence”. In Italy, among the most important monuments and places remained in the dark, we can mention the Duomo in Milan, the Colosseum in Rome, the Mole Antonelliana in Torino, the Arena in Verona, Piazza San Marco in Venice, as well as many other Italian squares and monuments.

Colosseum (Rome) in dark.

Colosseum (Rome) in dark.

Torino in dark.

Mole Antonelliana (Torino) in dark.

San Pietro (Vatican) in dark.

San Pietro (Vatican) in dark.

 

Brescia in dark.

Loggia (Brescia) in dark.

In 2008, the President of the European Parliament, Hans-Gert Poettering, has endorsed the initiative, calling it “an event that has a symbolic and a tangible effect”. The initiative had some followers also abroad: sometimes, the foreigner twinned towns have been involved. Among the others, the following monuments were turned off: the Eiffel Tower in Paris, the Custom House in Dublin and the Foreign Office in London.

An unforgettable edition was that of 2011, coinciding with the sesquicentennial anniversary of the unification of Italy. In this edition, “M’illumino di meno” was celebrated by turning off the lights and switching on “clean” lights on an Italian flag.

Although short-lived, the event is also rated in terms of actual energy savings. As reported by Terna, the company responsible for the transmission of electricity in Italy, in the minutes after the beginning of the initiative, there has been a significant decline in consumption. The need for instant energy recorded was about 300 MW less than in 2007, more than 400 MW in 2008, and about 500 MW in 2010, value representing a consumption of 8 million light bulbs.

It is possible to check the success of the 2006 edition of "M'illumino di meno" using the following chart, provided by Terna and related to the consumption of energy of the day February 16, 2006, in which it is evident (circled in yellow) the collapse of the real consumption (red line) compared with that normally scheduled for 18:00 (yellow line).

It is possible to check the success of the 2006 edition of “M’illumino di meno” using the following chart, provided by Terna and related to the consumption of energy of the day February 16, 2006, in which it is evident (circled in yellow) the collapse of the real consumption (red line) compared with that normally scheduled for 18:00 (yellow line).

So, on February 15th, 2013, individuals and organizations are asked to turn off their lights and other electrical devices powered by non-renewable energy sources. At the same time, lights from renewable sources are actively encouraged to be turned on. Mayors, citizens, teachers, students, factories, shops owners and workers, are also asked to find convenient and creative ways to turn on red, white and green lights, to show how important is facing environmental causes for the whole country. The campaign is also enriched with numerous local initiatives, such as zero impact exhibitions and concerts. At present, several cities have announced their participation at the iniziative. Among the others, we cite: Milan, Bologna, Florence, Torino, Bari, Padua, Agrigento, Genoa, Pisa, Matera, and many others.

During the event “M’illumino di meno” of 2010, the radio program Caterpillar told about the symbolic initiative of the construction of a special photovoltaic torch who crossed, like an Olympic torch, several Italian cities and some institutions (e.g. the Vatican City and the Quirinal). The torch, built in the style of the Olympic torch, was the first in the world to be built with renewable technologies: the power supply is fully guaranteed by photovoltaic modules that allow the lighting of the “brazier” realized with high efficiency LED microprocessors controlled by random functions for a realistic simulation of the flame. There is also a module that allows the torch to switch on automatically and uninterruptedly in the presence of light without the need to activate it.

This year, as usual, during the month leading to the event day, the radio program Caterpillar explained what each of us can do and how we can really change our routine energy habits in order to reduce wastes. Suggestions, hints and initiatives to emulate were told on Caterpillar radio show, by scientists and by common people. Hints explained by experts and “grandma’ remedies” has involved the audience in a thrilling ethical environment competition of good practices.

I am concluding this post by reporting here the decalogue of “M’illumino di meno”, to be interpreted as good habits not only for the special day, but for every day practices.

  1. At home and at work, remember to turn off lights when not needed! In addition, by replacing incandescent bulbs with low consumption ones, can be reduced by 7% of the total annual consumption of electricity;
  2. Turn off and do not leave appliances on standby electronic household and in the workplace. In this way you can reduce the consumption of electricity from 5 to 10%;
  3. Check the temperature of your home and the workplace. Reducing the temperature by just 1 ° C can cut consumption and related costs by 5-10% per year. During the summer it is recommended to set the temperature of air conditioners no more than six degrees less than the outside temperature;
  4. Frequent defrosting the refrigerator, taking the coil clean and spaced from the wall to facilitate the circulation of air. Also, remember that the recommended temperature for the refrigerator is between 1 and 4 °C and for the freezer is -18 °C. For each degree below these temperatures consumption will increase by 5%;
  5. Put the lid on pots when boiling water and avoid long as the flame is wider than the bottom of the pot;
  6. If you are too hot down the radiators instead of opening the windows;
  7. Do not use the pre-wash cycle of the washing machine. Avoiding this step, you can save up to 15% of energy;
  8. Insert special insulating films and reflective of the exterior walls and the radiators;
  9. Use curtains to create spaces in front of the glass, windows, outside doors and do not leave curtains closed in front of the radiator;
  10. Use the car as little as possible and, if necessary, to share it with those who make the same journey. Alternatively, choose to go to the place of work using a bicycle or public transport. Pay attention to tire pressure if it is lower than 0.5 bar, the car uses 2.5% more fuel. Furthermore, using a low viscosity oil for the engine, can reduce fuel consumption by more than 2.5%. Even in car air conditioning not abuse that increases overall consumption by about 5%.
2012 global temperatures: still in medal zone!

2012 global temperatures: still in medal zone!

Another year has already passed. So let us comment what happened in 2012, initially at global scale and then zooming on Europe and on Italy. As usual, while we wait for the official data that will be published in the next two – three months from institutional sites (CRU, GISS, NASA, etc. – the detailed list can be found on last year’s post), the fastest method is to use the database NOAA/NCEP (in particular, I have used this site with monthly composites). I remember that these are not raw but processed data: in particular, they are averaged on a grid of 2.5 degrees in longitude and latitude, which is equivalent, at our latitudes, to a square of about 300 x 300 km2. It is therefore impossible to make local considerations using this type of data.

Surface temperature anomaly (°C) in 2012 with respect to the reference period 1981-2010. Data NOAA-NCEP.

Surface temperature anomaly (°C) in 2012 with respect to the reference period 1981-2010. Data NOAA-NCEP.

The annual mean anomaly (note that the graphs in this post, unless otherwise stated, are all referred to the thirty years 1981-2010, which is the most recent period, to account for the warming occurred in the last three decades) shows a positive mean value, with the highest values in the Arctic and Antarctic polar regions, over Canada and the United States, and a narrow strip of territory stretching from the Mediterranean to Siberia. The most evident negative anomalies are concentrated in three small areas (Alaska, Mongolia and a portion of the Antarctic coast). For the rest, the anomalies remain (in absolute) below 1°C, and are prevailingly positive in the northern hemisphere over south-central Europe and North America, and negative in part of Asia and Northwestern Europe, while in the southern hemisphere, excluding Antarctica, show a less clear signal.

Globally, the mean anomaly was 0.26 °C, i.e. 0.07 °C higher than that of 2011, equal to 0.19 °C. This value is in fifth place in the scale of thermal values calculated using the NOAA-NCEP data, 0.09 °C away from year 2005, which leads the list. In football jargon, we would say that 2012 has earned Europe League qualification. In absolute terms, however, the integral data on the grid points (weighted by their respective surface, of course) is 14.30 °C. This numerical value, however, should be corrected to make it compatible with the values of other datasets. I will shorthly explain here how. Referring to the data (Table and figure below), we can see how the data NOAA-NCEP result, on average, underestimated by about 0.35 °C. I underline here that, concerning the data GISS, CRU and NCDC, both in the table and in the figure, for the year 2012, the average values referred to the period December 2011 – November 2012, instead of the annual average, not yet available, have been used (however, looking at the values of the past years, the difference, in general, is not higher than 0.02 ° C).

Annual mean values and anomalies for the three major databases, in comparison with the values calculated by the database grid points NOAA-NCEP used in this post. 2012 mean values, for the databases CRU, GISS and NCDC, refer to the period December 2011 - November 2012 and are shown in italics. The last column shows the NOAA-NCEP values "corrected" by adding the average difference in the 1981-2010 thirty years between the average of the other three databases and the average NOAA-NCEP, equal to 0.35 °C.

Annual mean values and anomalies for the three major databases, in comparison with the values calculated by the database grid points NOAA-NCEP used in this post. 2012 mean values, for the databases CRU, GISS and NCDC, refer to the period December 2011 – November 2012 and are shown in italics. The last column shows the NOAA-NCEP values “corrected” by adding the average difference in the 1981-2010 thirty years between the average of the other three databases and the average NOAA-NCEP, equal to 0.35 °C.

Let us note here that, in the past year, the CRU database has been slightly modified (see for example here), so some numerical values may slightly differ from previous assessments. In any case, the comparison reveals that, more or less, all databases are in agreement on the measurements and show the 2012 as warmer than the average of the most recent thirty years. On the other hand, the first year colder than period 1981-2010, for three databases on four, is the 2000 …, while to find the first year colder than period 1981-2010 for all four databases, it is necessary to go back to 1996!

Annual average values for the three major databases, in comparison with the gridded values calculated by the database NOAA-NCEP used in this post.

Annual average values for the three major databases, in comparison with the gridded values calculated by the database NOAA-NCEP used in this post.

However, beside the classifications, which can not be devoided by errors (observational, of average, station selection, interpolation, etc..), it is interesting to see how, if we take the ten-year period 2003-2012, it contains eight of the ten warmest years.

The signal is not present only at the surface: in fact, the map at 500 hPa (level corresponding to about 5500 m a.s.l., i.e. in the middle of the troposphere) shows values a bit smaller but still of the same sign, indicating that the warming occurred in the whole troposphere and not only of the surface stations (or of the boundary layer).

500 hPa temperature anomaly (°C) in 2012 with respect to the reference period 1981-2010. Data NOAA-NCEP.

500 hPa temperature anomaly (°C) in 2012 with respect to the reference period 1981-2010. Data NOAA-NCEP.

Let us go now to examine the graphs related to individual seasons. The winter 2011-2012, which includes December 2011, shows a strong warming on the Arctic regions, with maximum values between Svalbards and Siberia larger than 16 °C, but is also great on Canada and the United States, while practically all the Central Asia (from Caspian Sea to Korea), West Africa and the areas around the Bering Strait show anomalies of -4/-5°C. Unlike the Arctic, however, Antarctica shows less significant and more varied values, and also part of Greenland has recorded temperatures below average.

Surface temperature anomaly (°C) in 2012 with respect to the reference period 1981-2010. Data NOAA-NCEP.Surface temperature anomaly (°C) in 2012 with respect to the reference period 1981-2010. Data NOAA-NCEP.

Surface temperature anomaly (°C) in 2012 with respect to the reference period 1981-2010. Data NOAA-NCEP.Surface temperature anomaly (°C) in 2012 with respect to the reference period 1981-2010. Data NOAA-NCEP.

Concerning the spring 2012, different warm areas are noticeable on the Antarctic mainland, while in the Arctic only the area above the Eurasia maintains strongly positive anomalies, in both cases with values of 6°C or more. Other hot spots are the United States and much of Europe, as well as north-western Asia and part of Greenland. Areas with strong negative anomaly practically do not exist, except for part of Alaska and a portion of Antarctic coasts.

Surface temperature anomaly (°C) on the period March - May 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

Surface temperature anomaly (°C) on the period March – May 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

Summer 2012 is the season with the more moderated extreme anomalies. Almost the entire northern hemisphere has the land warmer than average, with rare exceptions (Great Britain and Scandinavia in Europe, and a small Siberian region over Mongolia in Asia), while in the southern hemisphere the oceans show more positive anomalies, and negative ones are present in the western parts of South America and Africa, and Australia. The most negative anomalies, however, are recorded on the Antarctic coastal areas, with values lower than -3°C, while inside there is the largest positive anomaly (more than 4°C).

Surface temperature anomaly (°C) on the period June - August 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

Surface temperature anomaly (°C) on the period June – August 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

The fall 2012 shows a configuration with distinctly positive anomalies on Arctic areas (with maximum larger than 8°C and peaks of 10°C) and still positive on part of the continents in the northern hemisphere (except the region between Alaska and Canada and Central Asia) and Antarctica (with the exception of the Antarctic Peninsula and neighbour sea, which show the minima anomaly, lower than -4°C). In the southern hemisphere, there are some spots with slightly positive anomaly.

Surface temperature anomaly (°C) on the period September - November 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

Surface temperature anomaly (°C) on the period September – November 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

For completeness, we show also the image for the month of December 2012, which completes the analysis of the year, as the distribution of anomalies is singular. Obviously, being an average on only one month, the mean anomalies are larger. Northern America, Alaska and western Canada are colder than average (minimum around -5°C), while the eastern part, from the United States to Greenland, recorded positive anomalies of 2-3°C. In Eurasia, the areas close to the Arctic Ocean show very positive anomalies, over 10°C, while almost all continent, with the exception of Western Europe, and southeast Asia, show strong negative anomalies, with values between -5°C and -10°C. In the southern hemisphere, the anomalies are less noticeable: slightly negative in Argentina, Chile and Mauritania, and weakly positive in Brazil, South Africa, Australia and Ethiopia; positive, with peaks larger than 5°C over most of Antarctica.

Surface temperature anomaly (° C) on the month of December 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

Surface temperature anomaly (° C) on the month of December 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

Let us now look in more detail the situation on the European continent. Apart from the Arctic (where anomalies exceeded 6°C), we see that the whole Europe, with the exception of Portugal, Great Britain, Scandinavia, Baltic States and a small piece of Russia, was under a positive anomaly, albeit lower than 2°C. The hottest areas include south-eastern Italy, Greece, Romania, Bulgaria, the Black Sea and a strip between Armenia and Azerbaijan.

Surface temperature anomaly (° C) on the period December 2011-February 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

Surface temperature anomaly (° C) on the period December 2011-February 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

It is interesting, in this regard, to see also the map of the anomalies of geopotential height at 200 hPa (hereinafter called Z200), a level typical of the lower stratosphere. The graph shows a good correspondence between the positive thermal anomalies of temperature and those positive of Z200, while the negative anomalies of Z200 match with null or slightly negative anomalies of temperature.

200 hPa geopotential height anomaly (in m) relative to the period December 2011-February 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

200 hPa geopotential height anomaly (in m) relative to the period December 2011-February 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

This finding can also be generalized to a global scale, as the good symmetry between the map of thermal anomaly at ground level and that of the Z200 is still evident. These maps visualize the correlations between tropospheric and stratospheric circulation, not yet fully understood in their details but under study (among others, I cite this 2007 paper in which Cohen et al. discuss the events of interaction between the stratosphere and troposphere in the extratropical regions).

200 hPa geopotential height anomaly (in m) relative to the period December 2011 - February 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

200 hPa geopotential height anomaly (in m) relative to the period December 2011 – February 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

Recently, the National Oceanic and Atmospheric Administration (NOAA) said that, in the continental 48 states of the US, 2012 had an average temperature of 55.3°F (12.9°C), which eclipsed 1998, the previous record holder, by 1°F (0.55°C). The 1°F difference from 1998 is an unusually large margin, considering that annual temperature records are typically broken by just tenths of a degree Fahrenheit. In fact, the entire range between the coldest year on record, which occurred in 1917, and the previous record warm year of 1998 was just 4.2°F.

Let thus see a map centered on the US: the anomaly here tops to more than 3°C between Nebraska and Kansas, and the isotherm 1.5°C contains most of the US.

Surface temperature anomaly (° C) on the period December 2011-February 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

Surface temperature anomaly (° C) on the period December 2011-February 2012 with respect to the 1981-2010 reference period. NOAA-NCEP data.

Now we would see some zooms in some meteorologically interesting periods. The year that has just ended was characterized, overall, by a series of significant weather phenomena. Among others, Italians remember the intense cold wave in first half of February (with extreme thermal values not seen since 1985-86 and, in some areas, heavy snowfalls also in the plains, that created serious problems), the very hot and dry summer in central and southern Italy (probably the warmest of the last 100 years, maybe second only to that of 2003) and the moderate cold wave in early December, which put an end to a long period of above-average temperatures.

Let us start from the first two weeks of February 2012. The thermal maps show Europe completely covered by a negative anomaly (except for part of Scotland and Ireland, and Iceland), with very low values: -12°C. In Italy, the North was the most abnormally cold zone, with values below the average of 7.5-10.5°C, while moving Southwards, the anomaly, even if negative, becomes less conspicuous. Notice also how the mitigating effect of the Mediterranean, who entered in the 2011 winter with temperatures well above average, such as to favors some flooding episodes and even the generation of a Mediterranean hurricane (medicane: see here) near Corsican coasts, was almost absent in the western part.

Surface temperature anomaly (°C) on the period 1 - 14 February 2012, compared to the 1981-2010 reference period. NOAA-NCEP data.

Surface temperature anomaly (°C) on the period 1 – 14 February 2012, compared to the 1981-2010 reference period. NOAA-NCEP data.

Also some Asiatic regions have experienced cold weather at the beginning of the year. The map of the anomalies in the first two months shows a sort of bipolar situation, with a large negative anomaly over most of central and southern Asia, with the exception of the extreme southeast, and another huge and large positive anomaly over Siberia and Arctic sea. It appears as the cold air was displaced southwards of its natural position, and also in this case the map of the Z200 anomaly (not shown) presents some similarities.

Surface temperature anomaly (°C) on the period January  – February 2012, compared to the 1981-2010 reference period. NOAA-NCEP data.

Surface temperature anomaly (°C) on the period January – February 2012, compared to the 1981-2010 reference period. NOAA-NCEP data.

Coming again to Europe, we continue with the warm months: the anomaly map shows a dipolar situation over Europe, with the northwestern part of the continent cold and the rest under the influence of a heat wave that, in Italy, recorded 1.5-2°C above average over the Adriatic regions, and values less than 1°C over the Alps (on this site there are some additional consideration on Italian summer). The most striking positive anomaly was recorded in a narrow strip of land included between Romania and the Black Sea.

Surface temperature anomaly (°C) on the period May-August 2012 compared to the 1981-2010 reference period. NOAA-NCEP data.

Surface temperature anomaly (°C) on the period May-August 2012 compared to the 1981-2010 reference period. NOAA-NCEP data.

Finally, we analyze the situation that characterized the other, most moderate, cold spell of the year, recorded in the first two weeks of December. As in the previous case, the 0°C isotherm contains almost all Europe, except the southern part and the Mediterranean.

Surface temperature anomaly (°C) on the period 1 - 14 December 2012 compared to the 1981-2010 reference period. NOAA-NCEP data.

Surface temperature anomaly (°C) on the period 1 – 14 December 2012 compared to the 1981-2010 reference period. NOAA-NCEP data.

Concerning the rest of the world, everybody remembers the Hurricane Sandy, which flooded entire districts of New York; or the drought in the U.S.; or the extensive flooding caused by tropical cyclones in Madagascar and the Philippines. Fewer people instead remember the Hurricane Nadine, which did not cause serious damages, but stationed off the Azores for over twenty days with the status of a hurricane, going round and round in these parts, and double-tapping islands and giving some concern to meteorologists who feared its explosive entrance in the Mediterranean, fortunately not occurred. Born on Sept. 7, and died on October 4, with its 23 days of life as tropical, subtropical and post-tropical cyclone, of which 21.75 as a tropical/subtropical system, Nadine is ranked as the fifth long-lived hurricane of the history.

Hurricane Nadine photographed on September 15, 2012 (left) and his track from the time of his birth until his death (right).

Hurricane Nadine photographed on September 15, 2012.

Hurricane Nadine photographed on September 15, 2012 (left) and his track from the time of his birth until his death (right).

Hurricane Nadine track from the time of his birth until his death.

Look at the map of the anomalies of sea surface temperature, we can see that, particularly during the period in which Nadine flew over the Atlantic, the anomalies became negative, sign of the potent activity of water mixing carried by the Nadine winds. That is why fishermen, in tropical areas, usually do not fear, but rather wait, and hope, the hurricanes, whose mixing effect cools the surface waters, favoring the fish abundance.

Sea surface temperature anomaly (°C) on the period 15 - 30 September 2012 compared to the 1981-2010 reference period. NOAA-NCEP data.

Sea surface temperature anomaly (°C) on the period 15 – 30 September 2012 compared to the 1981-2010 reference period. NOAA-NCEP data.

Worldwide, the 2012 reserved another resounding record: the marine Arctic ice cap has shrunk as never before in recent decades (see this post by Real Climate): the minimum area occupied by marine ice at the North Pole was only 3.41 million square kilometers, value smaller than one half the average of the last two decades of the twentieth century! Climatologists know well the ice-albedo positive feedback, one of the most important ones. Let us see, therefore, if it is possible to find a direct effect of this anomaly of Arctic marine ice cover on its surface temperatures (SST). Well, the answer is positive: the actual area free of ice is the one that shows the most noticeably positive thermal anomalies, more than 4°C, with a peak of more than 7°C near the islands of Novaya Zemlya. Without detailing here hypotheses that still need further evidence, however, it is impossible to not underline that the ice-free horseshoe structure that, in September, surrounds the Greenland, is also present in the SST thermal anomalies, and has also an impact on the field of sea-level pressure anomaly, whose maxima are shifted on the continents.

Ice extent on September 16, 2012 (from the site NSIDC).

Ice extent on September 16, 2012 (from the site NSIDC).

Sea surface temperature anomaly (°C), related to the period September-December 2012 and compared to the 1981-2010 reference period. NOAA-NCEP data.

Sea surface temperature anomaly (°C), related to the period September-December 2012 and compared to the 1981-2010 reference period. NOAA-NCEP data.

Surface pressure anomaly (hPa) related to the period September-December 2012 and compared to the 1981-2010 reference period. NOAA-NCEP data.

Surface pressure anomaly (hPa) related to the period September-December 2012 and compared to the 1981-2010 reference period. NOAA-NCEP data.

The fear, in this case, is that the scientific findings will be later than the disappearance, in September, of the Arctic sea ice. As it is can be seen below, it may be possible that this fact could happen as early as within 4-5 years …

Estimated sea ice minimum volume from UW PIOMAS, and regression curve.

Estimated sea ice minimum volume from UW PIOMAS, and regression curve.

Last, but not least, we will report another record in 2012. At the remote meteorological station in Barrow, Alaska, for the first time the monthly averaged atmospheric CO2 concentrations exceeded the threshold of 400 ppm (parts per million – that is, over a million molecules of air, more than 400 are CO2) in the months of April and May. We would like to stress that Barrow station is remote, i.e. away from CO2 sources able to influence the measurements. The threshold of 400 ppm is purely psychological, and probably, less than three years later, also the global average will exceed it; however, this figure represents a signal that can not be overlooked, especially considering that other greenhouse gases such as methane, are increasing and every year set a new record of concentration.

The NOAA observatory's atmospheric in Barrow, Alaska.

The NOAA observatory’s atmospheric in Barrow, Alaska.

Note: part of this post has been published in Italian language here.