It has long been known that the US is sitting on potentially huge supplies of unconventional shale gas. But until recently, these reserves were very hard to exploit. Now, however, technological breakthroughs mean that many of the economic and technical concerns about exploiting shale gas reserves are being dealt with. Over the past three years, American production has soared. This year, the US overtook Russia to become the world's biggest gas producer for the first time in a decade.

The result is that the shipping terminals that the US built to receive liquid natural gas from overseas are now lying virtually empty. The rise of shale gas, which can be used to produce electricity, reduces dependence on domestically produced, but dirty, coal. If cars powered by electricity or gas improve, shale gas would also reduce reliance on Middle Eastern oil.

Both the EU and China are excited by the idea that they too may soon enjoy a shale gas bonanza. Chinese foreign policy has increasingly been driven by the need to secure energy supplies. But China looks as if it may have its own shale gas reserves, and has signed an agreement with the US to look into exploiting them.

The excitement in Europe is even more pronounced. Just as North Sea oil and gas supplies are running down, the British are hoping that they may discover exploitable supplies of shale gas in Wales and north-west England. The Poles, who have their own special reasons to fear energy dependence on Russia, also think they have exploitable reserves. Radek Sikorski, the Polish foreign minister, recently visited Houston to talk to the big US energy companies about shale gas.

Even if European reserves are not as promising as some hope, the EU still stands to benefit indirectly from American shale gas. Supplies of liquid natural gas from Africa and the Gulf, which might have gone to the US, are now being redirected to Europe - reducing the Union's dependence on Russian gas.

The geopolitical effects of all this may be already being felt. In recent months, western officials have noticed a distinctly more friendly tone in their dealings with Russia. The Russians have signed a new nuclear arms reduction treaty with the US, accepted the idea of tougher sanctions on Iran and responded to the air crash on Russian soil that killed the Polish president and his entourage with unexpected openness and sensitivity.

David Fuller's view The change has only just begun and there are already some significant economic and political consequences which Gideon Rachman mentions. The main benefit is that an energy-starved world has bought at least another 20 years before we face a depression-inducing energy crunch. However by then the world should have developed renewable energy in sufficient quantity and price competitiveness to prevent the dire outcome that some people still fear.

Among the losers are oil exporters who may have been counting on another spike above 2008's peak at $147 a barrel for crude in the not too distant future. However stronger global GDP growth over the longer term should enable oil exporters to do well, if not as well as they may have hoped. Offshore drillers may be in less demand, due to costs and BP's disaster in the Gulf of Mexico. There is likely to be less enthusiasm for subsidised renewables, not least for unsightly windmills, although not to the extent that these fledgling industries are mothballed. Instead, they will have to become more competitive. Development of the nuclear energy industry will not proceed at the pace expected only two years ago. Coal prices are unlikely to revisit their 2008 highs anytime soon.

People often ask me how they can profit from shale gas. Not by investing in natural gas anytime soon as all the supply is keeping prices low. One way is to own land containing rich shale deposits, although the extraction will certainly have its drawbacks, as the lead article above points out. The American contract drillers and parts suppliers are obvious candidates, but not necessarily the companies with shale gas development rights, at least not at today's prices for natural gas. I assume that national oil companies in the Ukraine, Poland, China and other countries rich in shale gas deposits will be among the major long-term beneficiaries as their resource is developed. An indirect benefit will be faster global GDP growth than might have otherwise been anticipated due to a previously feared era of energy shortages. So far, the biggest beneficiaries have been chemical and nitrogen fertiliser companies because of low natural gas input prices.