The answer may depend on a number of different factors. Supply is not among them since it has long been known that there are plenty of shale gas deposits around the world but the challenge was how to extract it. US technology has gone a long way towards solving this problem over the last decade but this is still a new industry. No one yet knows how much of the gas is recoverable, or at what cost, or how quickly production will decline. For instance, production has fallen more quickly at the Barnett Shale site in Fort Worth region of Texas than the developers had expected and this article offers some explanation

David Fuller's view The reason is clear: most wells do not maintain the hyperbolic decline projection indicated from their first months or years of production. Production rates commonly exhibit abrupt, catastrophic departures from hyperbolic decline as early as 12-18 months into the production cycle but, more commonly, in the fourth or fifth years for the control group. Pressure is drawn down and hydraulically produced fractures close.

Workovers and additional fracture stimulations may boost rates back to previous levels, but rarely restore a well to its initial decline trajectory. More often, a steep hyperbolic or exponential terminal decline follows attempts to remedy a well's deteriorating performance. This observation casts doubt on the validity of the common practice of "group curve fitting" used to predict EUR from early production in newer shale plays.

This recent article from the Financial Times highlights the potential of shale gas but also some political and environmental hurdles:

The implications are profound. Policymakers have faced a trilemma: how to make energy supplies secure, affordable and clean. Now an abundance of gas appears to provide the answer to all three problems at once. In the words of Tony Hayward, chief executive of BP, it is a "game changer" - certainly for America, and quite possibly for the world.

If western politicians get it right, they could transform their uneasy relationships with suppliers in potentially troubling countries such as Russia and Nigeria, while meeting carbon reduction targets without relying on nuclear and wind power, which can deliver electricity only at vastly inflated expense. The consequences will be greatest if Europe can emulate the upsurge in US production. If it does not, the effects will still be profound.

However, there are two problems that could prevent gas from being the "long-term energy solution" proclaimed this week by Jim Mulva, chief executive of ConocoPhillips, a US oil and gas group.

One is political resistance; the other is the danger of pollution that one analyst warns could pose a "Toyota-sized" reputational risk.

Scepticism about the gas revolution is understandable because change has come so fast. Until five years ago, US policymakers and energy executives were fretting about securing enough gas to make up for the decline in the country's own, sizable production. This year, the US has overtaken Russia to become the world's biggest gas producer for the first time in nearly a decade. Technical breakthroughs that allow companies to tap gas trapped in its vast shale reserves, until recently considered impervious, have allowed it to shut its doors to imports from distant countries. The industry now thinks it can produce from those reserves for 100 years.

The primary problem is politics, according to Philip Lambert of Lambert Energy. "There is only one thing that can stand between natural gas being the affordable, quick and material answer to the environmental challenge posed by the globalisation of energy use - and that is political unwillingness to accept gas as the fuel of choice."

In part because of concerns about excessive reliance on Russia, EU governments have committed themselves to renewables such as wind power, promising to derive 20 per cent of Europe's energy from those sources by 2020. As a result, the industry is being pushed away from the lowest-cost options for emissions reduction to higher-cost technologies such as offshore wind.

In the US, opposition to an increased use of natural gas comes not only from the politically powerful coal lobby resisting any erosion of its position but also from policymakers and Congress, largely focused on supporting renewables and nuclear power.

Policymakers on both sides of the Atlantic have been slow to accept that the outlook for gas supplies has been transformed.

The other problem is the potential environmental impact of shale gas production. Water, sand and chemicals are pumped into the ground under pressure, to crack the shale and create gaps so the gas can flow out.

In the US, this process of fracturing, or "fracking", has already caused concern among environmental campaigners and some politicians worried about possible contamination of ground water.

Michael Zenker of Barclays Capital, warns: "If fracturing was halted, there would be a serious dent in the supply outlook for North America."

If I summarise the main obstacles to shale gas production on a global basis over the next decade and more as: 1) environmental, 2) technological, and 3) political - how might this play out?

1) Extracting natural resources from the ground is a hazardous business so environmental considerations are paramount, not least in Europe. As the greenest fossil fuel, gas starts with an advantage regarding environmental issues, provided that it does not pose a serious threat to groundwater. I am under the impression that this has yet to be proved, particularly as chemicals are being used. These and their effects will have to be disclosed, to protect populations. If the chemicals used are found to contaminate groundwater, and cannot be substituted with benign alternatives, there will be a lot less shale gas produced anywhere near population centres in developed countries. Also, proof will be required that the process of "fracking" shale rock over a large area does not cause potentially serious seismic disturbances.

2) As for technological challenges in shale gas production, I am no geologist but it seems obvious that methods of extraction will improve, given the commercial incentive. We already know enough to assume that this is both a temporary and less costly problem, relative to extracting oil from shale rock or tar sands - an energy intensive process which is also a major polluter. Shale gas is also far more accessible than deep water oil reserves.

3) Regarding energy politics, it is anyone's guess as to how this will play out for shale gas. As the newest and potentially largest source of cost-effective energy since the discovery of coal and crude oil, shale gas should have a bright future. However, lobbying from rival and entrenched interests will be significant, as the FT article above points out. Also, some greens will never be happy with a non renewable fossil fuel, even a comparatively clean one. Nevertheless, the rapid development of shale gas in the USA, not least due to 'needs must' considerations, is encouraging for the industry. Shale gas ticks some very favourable boxes in terms of reduced energy costs, import savings for many countries, and reduced greenhouse emissions.

I think shale gas has every chance of becoming a hugely important source of global energy. It is already a big factor for the US economy. We can probably expect the increasingly rapid development of shale gas industries from Europe to China in the next decade, despite the environmental, technological and political issues mentioned above.

If shale gas really is a 'game changer', then there will be a number of winners and losers for investors to consider. This will require some lateral thinking and I offer preliminary lists, on a topic that Fullermoney will continue to address for so long as it is relevant:

Winners - The global economy, which should not only recover from its deflationary shock, but other things being equal, could prosper in another period of synchronised GDP growth, fuelled by affordable energy. Countries rich in shale gas deposits will be among the most obvious beneficiaries, including Poland and the Ukraine among developing countries, but all emerging economies will also see their chances of rapid development increase, subject to governance, without 2008's threat of energy shortages. The bull market in global equities should be extended, subject to interest rate cycles. Companies that service the shale gas industry, including - leading producers, license holders, drillers, equipment manufacturers and builders of gas-fired power stations should benefit - subject to their competitiveness.

Losers - The primarily crude oil exporters, from OPEC to Russia. They should not lose drastically since oil will remain the main source of energy for a long time, but prices are unlikely to reach levels often forecast only two or three years ago. High-cost oil producers and oil refiners will do less well. Renewable energy companies - wind, wave, solar, and bio-fuel - many of which are reliant on costly subsidies, face less certain futures. Nuclear power - its day will come, as will the renewables, but there is now less of an emergency. Nuclear and renewables are very expensive industries which can now be developed at a more leisurely pace. Cash-strapped and deficit-riddled countries have committed themselves to these costly sources of energy, but good governance should lead to a reassessment of financial priorities, in the light of new and highly important information.

Subscribers will add to these lists of winners and losers, in the event of further evidence that shale gas really is a game changer. Meanwhile, they are based on conjecture, as is any forecast, since no one knows what the future holds. Where these lists of winners and losers are either right or wrong, you will see the evidence in the price chart action for the areas concerned. (See also Eoin's latest comments on shale gas below.

Here is an additional table from the FT: