Pensionato

A 72 anni Jim Hansen ha deciso di farsi crescere la barba, era più carino senza, e di lasciare il GISS della NASA per dedicare più tempo all’insegnamento e la ricerca all’università Columbia, e alla militanza praticata finora durante le ferie:

Dr. Hansen made it clear that his new independence would allow him to take steps he could not have taken as a government employee.

Comprare aranci. Continuerà a farsi arrestare, come il 13 febbraio scorso, davanti alla Casa Bianca nell’ennesima protesta contro il bitumodotto Keystone XL

Da Realclimate, i neodottorati Marcott et al. spiegano la loro ricostruzione delle temperature dell’Olocene.  Fra i commenti raccomando quello di Ray Pierrehumbert (senza barba non me lo vedo).

Il sociologo Roger Pielke Jr sospetta Marcott et al. di misconduct, pretende una correzione al paper, la smentita di un comunicato stampa per una frase (corretta) non attribuita agli autori, nonché di articoli (corretti) sui media. Poi afferma:

There are a few bad eggs, with the Real Climate mafia being among them, who are exploiting climate science for personal and political gain.

Evidence, please?

Bienvenue chez les kiwis

Sulla tournée neo-zelandese di Sua Signoria dalla rosa saracinesca, inventore della pillola che cura l’AIDS (altro video delirante) e oppositore della scienza del clima:

Dr James Renwick, associate professor of physical geography at Victoria University, dismissed Lord Monckton’s views as “rubbish”. “He’s a great showman and speaker, and climate change is a vehicle to self-publicise. But he has no training and has studiously avoided learning anything about science, I would say.” Professor Dave Frame, director of the Climate Change Research Institute at Victoria University, described him as a “vaudeville act” to be ignored.

Feedback negativo

L’Antartide perde circa 50 gigatonnel.  di ghiaccio continentale all’anno mentre d’inverno si espande la banchisa. Su Nature Geoscience, Richard Bintanja et al. dell’Uff. Meteo olandese confermano l’ipotesi del mare circostante che gela di più perché ci staziona sopra l’acqua meno densa dello scioglimento estivo. Un po’ la  scoperta dell’acqua calda:

Specifically, we present observations indicating that melt water from Antarctica’s ice shelves accumulates in a cool and fresh surface layer that shields the surface ocean from the warmer deeper waters that are melting the ice shelves. Simulating these processes in a coupled climate model we find that cool and fresh surface water from ice-shelf melt indeed leads to expanding sea ice in austral autumn and winter. This powerful negative feedback counteracts Southern Hemispheric atmospheric warming. … We suggest that cool sea surface temperatures around Antarctica could offset projected snowfall increases in Antarctica, with implications for estimates of future sea-level rise.

Se è così, sul continente nevicherà di meno.

Feedback positivi

Su Nature Climate Change invece, Richard Pearson et al. prevedono una riforestazione antartica:

we show, using climate scenarios for the 2050s and models that utilize statistical associations between vegetation and climate, the potential for extremely widespread redistribution of vegetation across the Arctic. We predict that at least half of vegetated areas will shift to a different physiognomic class, and woody cover will increase by as much as 52%. By incorporating observed relationships between vegetation and albedo, evapotranspiration and biomass, we show that vegetation distribution shifts will result in an overall positive feedback to climate that is likely to cause greater warming than has previously been predicted.

E i pinguini gli orsi polari? (grazie Paolo C.)

Jim Haywood del Met Office britannico et al. hanno trovato un’altra correlazione per spiegare la crescita della banchisa antartica durante l’inverno locale:

Using de-trended observations from 1900 to 2010, we show that three of the four driest Sahelian summers were preceded by substantial Northern Hemisphere volcanic eruptions. We use a state-of-the-art coupled global atmosphere–ocean model to simulate both episodic volcanic eruptions and geoengineering by continuous deliberate injection into the stratosphere. In either case, large asymmetric stratospheric aerosol loadings concentrated in the Northern Hemisphere are a harbinger of Sahelian drought whereas those concentrated in the Southern Hemisphere induce a greening of the Sahel.

Ma a che cosa era dovuta la quarta estate più arida?

Further studies of the detailed regional impacts on the Sahel and other vulnerable areas are required to inform policymakers in developing careful consensual global governance before any practical solar radiation management geoengineering scheme is implemented.

Quello di sicuro.

Feedback +/-

Due riversamenti di bitume canadese in una settimana: mercoledì un treno deraglia e sparge 15 mila galloni nel Minnesota; giovedì un pipeline della Exxon che si buca ne sparge 10 mila in Arkansas. Un’abitudine, ricorda il Guardian

The US Department of Transportation earlier this week proposed a fine of $1.7m for Exxon over pipeline safety violations relating to a 2011 oil spill in the Yellowstone River. Exxon’s Silvertip pipeline, which carries 40,000 barrels per day of crude in Montana, leaked about 1,500 barrels of oil into the river in July 2011 after heavy flooding in the area.

Per l’andamento dei ghiacci dall’altra parte e altre anomalie, rif. Tamino che scrive

None of the five main global temperature data sets shows statistically significant trend since 2003. But if they’re adjusted to remove the influence of known extraneous factors — el Nino, aerosols, and solar variation — there is one which does show a statistically significant trend despite being limited to a mere ten years and two months.

Its estimated trend since 2003 is 0.018 deg.C/yr, even higher than its estimated trend since these data begin in December 1978.

Le temperature UAH sono quelle derivate dai dati satellitari dagli “scettici” Roy Spencer e John Christy.

Aggiunt. More feedbacks

Steph riassume i meccanismi (anche ipotesi sui) climatici che contribuiscono all’ondata di freddo che staziona su parte dell’emisfero nord mentre dall’altra staziona il tepore. Inclusa la NAO questa volta.  C’è da leggere per mezza giornata e conviene avere un mappamondo a portata d’occhio.

A proposito di creazionisti come Roy Spencer, da Camillo elencano le cantonate nella Genesi secondo Ubaldo Mastromatteo. A chi soffre di allergia al nombrilismo solipsista, consiglio di saltare i commenti di Indopama anche se nel thread precedente provocava un fou rire con:

per finire,

no, momento

anche io lavoro nella scienza ed ho una formazione scientifica