La folle corsa alle sabbie bituminose


Contengono il doppio della quantità di ossido di carbonio emessa dal petrolio che usiamo dall’inizio della nostra era ad oggi. Il loro uso porterebbe a conseguenze apocalittiche: disintegrazione incontrollata dei ghiacciai, innalzamento intollerabile della temperatura, distruzione delle città costiere, estinzione del 20-50 % delle specie viventi

Irrazionale, è l’unica parola che può indicare la nuova febbre che sta prendendo alcuni Paesi a sposare ancora la corsa al petrolio, ma soprattutto al gas da scisti bituminose che sta avvenendo nel mondo.

In Argentina è stato scoperto il 3° più grande giacimento di scisti bituminose dopo quelli di Usa e Cina, ma anche in Europa ci sono degli «estimatori» come Polonia e Francia. E l’Iea, l’Agenzia internazionale dell’energia, già definisce le regole per l’estrazione del gas «non convenzionale», pur riconoscendo la forte opposizione degli ambientalisti come Greenpeace International.

Questo sarà uno dei più rilevanti problemi ambientali che si presenteranno a breve termine. Recentemente James Hansen, direttore del Nasa Goddard Institute for Space Studies, ha scritto un articolo per il «New York Times», particolarmente allarmante a proposito dei cambiamenti climatici. E, segnatamente al problema delle sabbie bituminose che il Canada si appresta ad utilizzare, sottolineava che esse contengono il doppio della quantità di ossido di carbonio emessa dal petrolio che usiamo dall’inizio della nostra era, 2,5 milioni di anni fa, ad oggi. Il loro uso porterebbe a conseguenze apocalittiche: disintegrazione incontrollata dei ghiacciai, innalzamento intollerabile della temperatura, distruzione delle città costiere, estinzione del 20-50 % delle specie viventi… compresa la nostra.

Ma tant’è, sono 30 anni che non riusciamo a metterci d’accordo su uno straccio di intesa internazionale per diminuire le emissioni di gas serra che stanno tranquillamente aumentando e dobbiamo preoccuparci per le sabbie bituminose?

Ma sì, chi se ne importa se fra qualche generazione staremo sull’orlo dell’estinzione?

Di seguito il comunicato Iea

The International Energy Agency (IEA) has unveiled a ‘golden’ rulebook for the extraction of unconventional gases such as shale, which it says is needed to give them a ‘social license to operate’.

The checklist includes more regulation, transparency, investment, environmental protection, and a switch to best practices. “If this new industry is to prosper, it needs to earn and maintain its social license to operate,” said the IEA chief economist Fatih Birol, the report’s chief author. “This comes with a financial cost, but in our estimation the additional costs are likely to be limited.”

According to the IEA’s long-awaited report – ‘Golden rules for the Golden Age of Gas’ – applying their rulebook “could increase the overall financial cost of development [for] a typical shale-gas well by an estimated 7%.” But Antoine Simon, an extractive industries campaigner for Friends of the Earth, an environmental group, was sceptical that such funding would arrive in time to meet Europe’s climate objectives. “It will take a long time and an enormous amount of investment that would consequently not be put into renewables and energy efficiency that could reduce emissions now,” he told. There was “nothing new” in the report’s executive summary, and the IEA appeared to be retreating from previous positions favouring renewables, Simon argued. “We find it quite worrying,” he said.

A clean energy?

Shale gas has been hailed as a ‘clean’ energy but a separate report last week by the Scottish Widows Investment Partnership found that current extraction techniques provide no greenhouse gas emissions savings at all.

This is because the process of hydraulic fracturing – or ‘fracking’ – which explodes dense clusters of rocks underground to obtain gas, also releases large amounts of methane into the atmosphere. Fracking has also sparked angry protests over fears of earthquakes, freshwater poisoning and other public health hazards, leading to bans on the practice in Bulgaria and France. Underlining public concerns is the problem that scientists say methane is between 20%-100% more potent than carbon dioxide as a greenhouse gas in the short-term.

One study by Cornell University last year found that as a result, shale’s climate impact was “worse than coal”.

However, if companies used a technology known as “green completion” to capture the “fugitive” methane leaks that fracking causes, the climate impact of shale could be minimised, according to the Scottish Widows report.

‘Golden age of Gas’

The IEA predicts that because of greater availability and climate concerns, the share of gas in the global energy mix will triple by 2035 to 1.6 trillion litres, or 25% of the global energy mix – a higher percentage than coal and second only to oil.

Unconventional gas will make up 32% of that figure, the IEA report says, fuelling a ‘golden age’ for gas that will, for example, enable the US to become self-sufficient in energy by 2030.

Poland too is planning a strategic move towards shale gas production beginning in 2014.

But the EU’s chief climate negotiator Artur Runge-Metzger has publicly questioned whether such heavy reliance on fossil fuels would allow the decarbonication by 2050 that scientists say is needed to limit global warming to two degrees Celsius.

‘Shale gas revolution’

To prevent the ‘shale gas revolution’ from sparking an atmospheric methane overdose – and public protests – the IEA recommends substantial operating changes by the industry.

Drilling sites should be chosen to minimise social and environmental impacts, they say, and environmental monitoring should be more extensively conducted and communicated to the public, at all stages of the drilling process.

A general performance standard for wells should be introduced involving robust rules on well design, construction, cementing and integrity that isolate gas bearing formations from other strata, particularly freshwater aquifers. Minimum-depth limitations should be imposed on fracking, while earthquake risks should be carefully addressed through geological surveys and site choices, the IEA says.

Environmental concerns about the pollution of underground freshwater sources with industrial chemicals should also be taken more seriously.

Freshwater use should be reduced, chemical additives minimised, emergency response plans strengthened, and flaring of natural gas cut back massively, it adds.

No panaceas

But even with adoption of all these caveats, shale gas use cannot be a panacea, the IEA report warns. “Greater reliance on natural gas alone cannot realise the international goal of limiting the long-term increase in the global mean temperature to two degrees Celsius,” it says.

As well as unconventional gas, energy efficiency, low carbon energy sources and technologies such as carbon capture and storage will all be needed, the report says.

Reacting to the report, Greenpeace International’s Chief Scientist Paul Johnston said: “Greenpeace opposes the exploitation of unconventional gas reserves because the impacts have not been fully investigated, understood, addressed and regulated. The impacts include high rates of methane leakage, severe water pollution and very high water consumption. The IEA report essentially affirms that these concerns are real but falls short of actually addressing them.”