Hydraulic fracturing, or fracking, is a process that injects water, sand, and chemicals into underground rock (usually shale) at high pressure to extract natural gas. But it is highly controversial. Supporters say it provides the US with a cheap source of fuel and helps provide jobs and prosperity, while opponents say it pollutes air and water.
Now, as fracking goes global, communities in South Africa, Poland - and beyond - have to decide between environmental concerns and big financial incentives from the energy companies.
The big picture
The Ecologist has partnered with Link TV's Earth Focus programme to contribute to the channel's Fracking hell: the big picture special:
- Fracking hell? Poland's dash for gas Fracking multinationals covet the sizable shale deposits lying deep in Poland's underbelly. Advocates say this will bring prosperity, but opponents cite the US experience -- where fracking is marred by environmental and social concerns --
- Fracking hell? The untold story A look at the risks of natural gas development in the Marcellus Shale: from toxic chemicals in drinking water to unregulated interstate dumping of potentially radioactive waste, are the health consequences worth the economic gains? Watch it
- How dairy farms suffer in US gas fracking boom. By Dimiter Kenarov. Read
- Youngstown: where promise and the curse of shale gas collide. By Dimiter Kenarov. Read.
- Livestock falling in in fracking regions, raising fears about food. By Elizabeth Royte. Read.
- How Poland's dash for gas turned sour. By Andrew Wasley. Read.
- Fracking our future: the corrosive influence of extreme energy. By Frack Off Read.
- Shale gas: the facts beyond the myths.By Monica V. Christina Read
- Middle England and activists unite to oppose shale gas rush. By Jan Goodey. Read.
- The environmental costs of the new US gas drilling boom. By Jim Wickens. Read.
- Shale gas may be 'dirtier than coal'. By Tom Levitt. Read
For full coverage of fracking by the Ecologist see here
Middle England and eco-activists unite in opposition to shale gas and fracking
In a perfect storm, Middle England is joining forces with climate activists to say no to fracking and the UK's much-talked about shale gas boom
UK urged to ban controversial 'fracking' gas-extraction
Gas extraction plans underway in Lancashire would pose a serious risk of contaminating ground and surface waters, says Tyndall Centre report
UK shale gas boom 'may be dirtier than coal'
The greenhouse gas footprint of fracking may be higher than that of coal. Tom Levitt reports from the centre of this potential unconventional gas boom near Blackpool
Shale gas fracking 'probable' cause of Lancashire quakes
Controversial 'fracking' technique to extract gas from the ground was the 'highly probable' cause of earth tremors, report finds
Europe's scramble for gas sees controversial hydraulic fracturing
Gas-extraction in the US has been linked to pollution and social conflict. Now Halliburton, Chevron and Exxon, among others, want to bring the so-called 'fracking' process to Europe