Natural gas, a fuel previously scorned as the scourge of coal miners, the poor relative of oil and the soiled rival to solar and wind power, has suddenly come of age.
Methane, the main constituent of natural gas, has always been a menace to coal producers. Last April, it was implicated in a West Virginia coal mine explosion that killed 29 workers.
Until recently, most oil producers regarded gas associated with crude as a nuisance, as efforts to make money from it required major investments in infrastructure.
Finding gas instead of oil was usually a big disappointment. Just last month, investors dumped the stock of Canada's Heritage Oil after it announced a large gas discovery in Iraqi Kurdistan instead of an oil strike.
Some environmentalists criticise gas for being neither carbon-free nor renewable, although it is certainly a lower-carbon energy option to coal or oil. Others say side effects from gas extraction include unacceptable levels of air and groundwater pollution.
Gas producers "are shameless and have immense resources to pay for spin", said the film director Josh Fox, whose Gasland documentary last year raised alarms about the recent US boom in shale gas drilling.
Some anti-gas activists resort to sabotage, as did Canada's Wiebo Ludwig who blew up several pipelines before being arrested at the start of last year.
But the International Energy Agency (IEA) says the third fossil fuel, which is still often burnt or vented into the atmosphere as waste, is about to enter its golden age. Others talk about a global "dash for gas".
"China could lead us into a golden age for gas," the agency said in its latest World Energy Outlook, released last November. It foresees China leading a surge in global gas demand to 4.5 trillion cubic metres in 2035 from 2.9 trillion cu metres last year.
The IEA expects Chinese gas consumption to rise by an average 6 per cent a year while Middle East demand grows almost as quickly.
The agency is not alone in its rosy long-term outlook for gas. Last summer, the Massachusetts Institute of Technology (MIT) published a study predicting a leading role for gas in coming decades.
"Much has been said about natural gas as a bridge to a low-carbon future, with little underlying analysis to back up this contention," says Ernest Moniz, the director of the MIT Energy Initiative. "The analysis in this study provides the confirmation."
The consultancy IHS Cera expects gas to transform the global energy industry, notably through the development of huge, newly exploitable gas resources such as shale gas and coal-bed methane.
"The biggest energy innovation of the decade is natural gas - more specifically, what is called unconventional natural gas. Some call it a revolution," the IHS Cera chairman Daniel Yergin and senior director of global gas Robert Ineson wrote in The Wall Street Journal in November 2009.
"It may be half a decade before the strength of the unconventional gas revolution outside North America can be properly assessed. But what has begun as the shale gale in the US could end up being an increasingly powerful wind that blows through the world economy."
Two years on and a global gas revolution is already emerging from the cloud cast by the world's first global gas glut. That took shape in 2009, as the recession sharply cut demand for gas to fuel industry and power plants. Spot prices for gas plunged. But US drillers kept tapping into vast shale beds, as much for valuable natural gas liquids as for gas itself, while international oil companies made large investments in North American shale-gas assets.
The drilling surge made the US the world's biggest gas producer in 2009, overtaking Russia. US gas exports to Mexico are rising, while US and Canadian projects to develop export terminals for liquefied natural gas (LNG) are attracting serious investment interest.
Last December, Sasol bought Canadian shale-gas assets from Talisman Energy for C$1.05 billion (Dh3.9bn). The South African and Canadian duo also agreed to study the feasibility of building a gas-to-liquids plant in western Canada, highlighting the potential for the North American boom to yield transport fuels.
Qatar, which was already the leading LNG exporter when the recession hit, continued developing the world's biggest cluster of production facilities for the super-chilled gas that can be shipped across oceans.
It is set to bring its final production train onstream in the coming weeks, boosting its total export capacity to 77 million tonnes a year.
Now Qatar is seeking to export its LNG expertise to Russia. Its government-owned Qatar Petroleum International is in talks with Russia's Gazprom and Novatek over a multibillion-dollar LNG project in Russia's Yamal Peninsula, says Vladimir Titorenko, the Russian ambassador to Qatar.
In Australasia, plans to develop 17 large LNG projects, including some fed by gas from Australian coal deposits, gained momentum.
If all proceed as planned in the next decade, they would require more than US$100 million (Dh367.2m) of capital investment and would boost the region's LNG output sevenfold to 117 million tonnes a year - the energy equivalent of 2.85 million barrels per day of oil, which is about the crude output capacity of Abu Dhabi.
Elsewhere, the search for shale gas outside North America is picking up steam, especially in China and India.
Late last month, India's state-owned Oil and Natural Gas Corporation struck gas in West Bengal with its initial well in the country's first shale gas exploration project.
"The breakthrough is significant as India is the first Asian country where gas was discovered from shale outside [the] US and Canada," the company said.
The discovery brought fresh hope that India could meet its domestic energy needs, it added.
In Europe, future gas supplies from shale are less assured. Didier Favreau, a senior analyst with the French consultancy Cedigaz, told the Gas Arabia conference in Abu Dhabi last week that environmental opposition and public rather than individual ownership of mineral rights would impede development in many European countries.
But Chevron held talks last week with the Ukrainian prime minister Mykola Azarov over shale gas development. On Wednesday, Kiev approved plans by Russia's TNK-BP to extract gas from Ukrainian shale beds.
Royal Dutch Shell, meanwhile, wants to drill shales below South Africa's semi-desert Karoo region. Local farmers oppose the project, fearing groundwater contamination.
Still, few revolutions proceed smoothly. "Development will require negotiations with governments and potentially complex regulatory processes," the IHS Cera report said.
"Existing long-term contracts, common in much of the natural gas industry outside the US could be another obstacle. Extensive new networks of pipelines and infrastructure will have to be built. And many parts of the world still have ample conventional gas to develop first."
Rising project costs are another headache for gas developers while prices stay low compared with crude. The IEA says the global gas glut has yet to peak.
Meanwhile, analysts warn Australian LNG projects face serious cost overruns as labour competition intensifies.
On the other side of the coin, developers of renewable and nuclear energy increasingly perceive gas as a threat. Analysts blame low gas prices for cancelled US nuclear projects and a drop in wind turbine installation.
Ever the savvy promoter, the veteran Texan energy financier T Boone Pickens has switched to talking up gas instead of wind power to rid the US of reliance on foreign oil.