This resource requires special extractionmethods to get it out of the ground and into a form where it is fluid enough to travel down the pipelines for refining into gasoline and other hydrocarbon products.
But critics of human cloning and stem cell extractionmethods essentially believe a human egg that begins to divide for any reason should be considered an embryo, and a potential person, that deserves protection under the law.
In April 2012, a study by scientists at the US Geological Survey of the interior of the US found that events of magnitude 3 or greater had "abruptly increased in 2009" from 1.2 per year in the previous 50 years to more than 25 per year - although a number of gas and oil extractionmethods may be implicated in the rise.
New fracking methods are transforming oil and gas extraction productivity, providing access to at least 167 shale oil and gas field deposits that are distributed among several states.