NEWS

Over many years coal emits more CO2 than oil sands, but could deliver more energy too

Climate scientists Neil C Swart and Andrew J. Weaver attempted to balance out the economic benefits of producing and exporting oil derived from oil-sands  versus the impact the industry will have on CO2 emissions and a global average temperature rise in an article published in Nature [1]. Burning the country’s entire Alberta oil-sands resource would have less impact on a global temperature rise (contributing to a 0.4 degC rise) compared with burning the world’s entire coal resources (14-15 degC rise); and even be less than the impact of burning natural gas (contributing to a 3 degC rise).  There is no surprise in the facts that the global warming potential (GWP) for coal is much higher than natural gas, and the uncontrolled burning of coal leads to air pollution and health problems.  However, as a mere observation, Dr Weaver has alluded to the very important issue from these findings, and that is the abundance of coal.
The massive 15 degC rise from burning all of earth’s coal reserves is indicative of the GWP of coal, but goes further to suggest there is a great deal more coal left in the world compared with natural gas and indeed Canadian coal sands.  In a way, Dr Weaver has unintentionally endorsed the energy security provided by today’s world coal reserves.  And based on the assumptions on climate change and coal burning, peak coal clearly has a long way to go.  However, and more seriously, this energy security comes with a price, and to exploit any such coal reserves (or indeed any fossil fuel reserves including oil-sands) should be done with an equally vigorous pursuit of CCS so as to ensure this 15 degC, or indeed any temperature rise never materialises in a form that could cause a manmade shift in the climate and weather. Swart and Weaver briefly mention that CCS could reduce CO2 from oil-sands production, but is clearly an area that requires more investigation and needs a more positive boost from the general news media.
As a last point, Canada’s wealth in coal reserves is sometimes overlooked, and goes beyond just digging out lumps of coal from the earth. The potential for Canada’s coal bed methane and underground coal gasification dwarves the potential in many other countries.  Geological surveys suggest that current reported reserves and resources need updating and realistic figures suggest Alberta alone has coal reserves of 33 billion tonnes. Resource figures (as opposed to reserves figures) of 2000  billion tonnes are being reported to include deep seams unmineable using conventional digging methods, with a potential for 620 billion tonnes that could be used if underground coal gasification were to be successfully commercialised on a large scale [2]. These coal resource numbers are truly vast, considering global production is currently more than 6 billion tonnes per year.  It would be a twist in the tale if Alberta exploited its vast coal reserves (in an environmentally friendly manner), yet outlive oil-sands and natural gas by hundreds of years.

(1) Swart N C and Weaver A J (2012) The Alberta oil sands and climate. Nature Climate Change (19 Feb 2012)
(2) http://www.ai-ees.ca/media/23893/vast-coal-resources-6-international-conference-underground-coal-gasification.pdf

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