Slowdown

Spiace per chi crede che l’era glaciale è iniziata nel 1999, ma la temperatura globale continua a salire. A febbraio ha battuto i record di GISTemp, ERA e JMA, all’appello manca solo HadCRUT di solito un filino più basso.

Non che i dati possano essere uguali, ogni serie è diversa per quantità di stazioni, linea-base, metodo di calcolo e addirittura tipo di grafico (ERA lo fa apposta per  confondere le idee a noi cronisti?).

Nelle stime preliminari dell’Agenzia internazionale per l’energia, il 2015 conferma il “disaccoppiamento” tra crescita economica ed emissioni di gas serra iniziato nel 2014:

Global emissions of carbon dioxide stood at 32.1 billion tonnes in 2015, having remained essentially flat since 2013. The IEA preliminary data suggest that electricity generated by renewables played a critical role, having accounted for around 90% of new electricity generation in 2015; wind alone produced more than half of new electricity generation. In parallel, the global economy continued to grow by more than 3%, offering further evidence that the link between economic growth and emissions growth is weakening.
(…)
The two largest emitters, China and the United States, both registered a decline in energy-related CO2 in 2015. In China, emissions declined by 1.5%, as coal use dropped for the second year in a row. The economic restructuring towards less energy-intensive industries and the government’s efforts to decarbonise electricity generation pushed coal use down. In 2015, coal generated less than 70% of Chinese electricity, ten percentage points less than four years ago (in 2011). Over the same period low-carbon sources jumped from 19% to 28%, with hydro and wind accounting for most of the increase. In the United States, emissions declined by 2%, as a large switch from coal to natural gas use in electricity generation took place.
The decline observed in the two major emitters was offset by increasing emissions in most other Asian developing economies and the Middle East, and also a moderate increase in Europe.
Rif. anche The Economist

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Il futuro della mobilità urbana…

L’oca Filippo segnala una ricerca sulla mobilità e il tempo perso negli ingorghi urbani uscita su Nature Communications, co-autore un dottorando “fiero di essere siciliano” che la settimana scorsa ne aveva pubblicato uno preliminare su Interface (bozza gratis). Tiene conto anche dell’effetto del comportamento egoista o altruista degli automobilisti sul traffico di Boston, San Francisco Bay Area, Rio de Janeiro e Porto:

In the previous section we characterized the percentage of potential savings that can be obtained for increasing levels of social consideration. However, these benefits are achieved at the expense of time of drivers who adjust their commute for the benefit of others. The unwillingness to give up time is the defining factor in drivers’ failure to reach an optimal state on their own. This highlights the importance of fairness of the distribution of who has to sacrifice versus who benefits in terms of both the success potential of the implementation of policies or a reward/punishment reinforcement schema.

Il “social routing”  – l’informatica che dovrebbe migliorare la mobilità – penalizza gli altruisti, “a beneficio della città nel suo insieme”

The advantage is that in the context of the implied routing application, the number of vehicles sacrificing their travel time is significantly smaller than the number of those that benefit. Lower levels of weight towards social good will also moderate the magnitude of benefits and losses, consequently making the policies fairer and easier to implement.

Conclusioni temporanee:

As the volume, the variety and the resolution of data increase along with the expected disruptions from connected self-driving cars and similar technologies, this front of research will become more relevant to facilitate the study and planning for the future of urban mobility. With more updated demand models extracted from communication technologies, understanding the network effects on congestion will become easier to pinpoint and address. In addition, planning tasks on urban mobility previously difficult to tackle may now be addressed at lower costs and with much larger samples of the population. For example, a thorough analysis of how travel time and congestion is distributed among the population and its split by income and other sociodemographic characteristics remains an open front.

Se ne discute da The Conversation, e si possono fare i complimenti ad Antonio Lima su twitter.

3 commenti

  1. Grazie per l’informazione, sapevo che potevo contare sulla tua competenza.
    Purtroppo il mio amico si trova nello stato di vulnerabilità di chi è disperato.
    Spero almeno di impedirgli di fare assumere un veleno allo sfortunato fratello.
    Per fortuna è un tedesco di Wiesbaden; se vuole può avere tutte le informazioni che desidera.
    Saluti.

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