This excellent documentary, directed by Dr. Richard Smith, was first broadcast on 24 May 2007 by ABC TV (Australia) and wan the 2008 Walter Sullivan Award for excellence in science journalism. You can buy the DVD or watch it with extras on this, also excellent, web page: http://www.abc.net.au/science/crude/
The Irony of Oil (taken from the above site):
It took a super-greenhouse earth to create our richest oil deposits. Ironically, by using oil up we may recreate the toxic conditions necessary to form new supplies. Oil lives on. But will we?
In the mid-Jurassic, huge swathes of microscopic phytoplankton fell to the bottom of stagnant seas, taking trapped sunlight and carbon dioxide with them. Under the right temperature, pressure and geological conditions, the phytoplankton were cooked until their contents were converted into long chain hydrocarbons. The result was crude oil-liquid, fossilised sunlight.
The basics of the story of oil have been known for decades. But while geologists once thought the huge oil deposits on which modern Iife and economies are based were formed because of favourable Iocal conditions – a particularly fertile coastline, or a naturally stagnant patch of seafloor – the evidence now paints a very different picture.
To form Iarge reserves of oil, it seems that you need two interlinked global catastrophes – a super- greenhouse effect for warmth, and stagnant, oxygen-depleted oceans for preservation. And that was very much the picture of the earth 50 million years ago, when all our richest oil regions were beginning to form.
Indeed, locking away the excessive atmospheric CO2 on the sea floor was the only thing that brought balance back to our ancient climates and oceans, and made the planet habitable again. The period of supergreenhouse ended, and ice on the poles of the cooling planet was again able to drive the ocean conveyor belt, returning oxygen to the deep seas.
In the Iast 150 years we have released much of the ancient carbon from oil back into the atmosphere as CO2, driving the now familiar greenhouse effect. But things could get far worse. Ironically, it seems that as we burn our way to the end of oil, the CO2 we’re returning to the atmosphere could recreate the supergreenhouse conditions that would heat and poison the oceans, once again laying the conditions for depositing oil.