Posted by: ericgrimsrud | December 19, 2013

The Nitty Gitty of that paper by Hansen et al.

In my previous post entitled “Why the gloom and doom”, I referred to a very recent paper by Hansen et al. in which a group of climate experts described the present state of the Earth’s climate.  (To see the full paper again, click here.)  In that paper, they provide a figure that lays out the challenge before us.  It is shown below:


In this figure the amount of carbon (in units of Gigatons) that has been emitted or will possibly be emitted into our atmosphere (in the form of CO2) from various sources of fossil fuels that are now available.  The sources include conventional oil, gas and coal and unconventional oil and gas.  The unconventional fossil fuels are those being recently developed by the extraction of oil from tar sands and the release of oil and gas following the fracking of shale deposits. The various colors in each column indicate the amount already used to date (purple), the readily available amount remaining (blue) and the amount probably available if we continue to look for more (yellow).

Before considering each of the columns in the figure, lets first consider the most important conclusion of this paper.  That is that in order to allow the Earth to remain in its present state of stability, mankind must not burn more than about 500 GtC total over its entire industrial period that began about 160 years ago.  With the emission of more carbon than 500 GtC, the authors expect that the Earth’s climate will leave its present stable state and enter into an unstable one that will subsequently drift into progressively warmer and distinctly untenable states in which human civilizations could no longer exist in their present forms.

OK, so we are allowed to emit 500 GtC total between 1850 and some unknown future date when we do manage to terminate all carbon emissions.  So next,  how much carbon have we emitted to date?  The answer to that question is provided by the sum of the three purple bars showing emissions to date of conventional oil, gas and coal.  These are 130, 60 and 180, respectively, for a total of 370 GtC.  Note also that so far we have used only a negligible amount of the newer unconventional forms of fossil fuels.  So what does that leave us for allowable future use?  The answer is 130 GtC (500 – 370),  right?.  With that number (130 GtC) in mind, let’s now consider the various fossil fuels we have left in the ground.

Let’s first consider the amount of readily available conventional oil and gas shown by the blue bars in the first two columns.  These indicate that we have about 140 GtC of conventional oil and 90 GtC of conventional gas readily available for our future use – for a total of 230 GtC.  Oh, Oh!  We already have a problem – we are allowed to use only 130 GtC.  Therefore, we already have about 100 GtC more  readily available gas and oil than we will be allowed to use – again, that is if we want our planet to remain in a stable condition.

So what does this mean?  It means that we will have to leave about 100 GtC of our most readily available and very valuable gas and oil in the ground.  That will be tough to do, of course, because these are the cleanest,  most portable, most  available, most energy rich and most valuable forms of fossil fuels that we have.

Next note the top yellow portions of the first two columns.  If we continue to try harder and drill more, we can almost double our future supplies of conventional oil and gas.  While the oil and gas companies would like you to shout “whoopee!” to these prospects and allow them to explored new regions of the world for its oil and gas deposits, anyone with a mathematically functioning brain should say “what the hell – why is anyone trying to find more sources of conventional gas and oil when we already have too much!”.

Now move on to the 3rd column concerning conventional coal.  Note that under its blue bar, we have  an enormous amount, about 550 GtC, of unused and readily available coal – just waiting to be scooped up and transported to power plants in the US or Asia.  So in response to that information, should we yell “oh no!” or “whoopii!” as do the coal companies? The answer is clear, is it not?  Since coal  generates only about half as much energy per CO2 molecule emitted as do gas and oil and because of the additional environmental and human health issues (associated with particulates and mercury) are raised by coal’s use, why would anyone who understands numbers want to use coal for power generation?  It is entirely clear, is it not, that no coal whatsoever should be used in the future. Gas and oil, only, and only 130 GtC of them can be used.  Nevertheless, we still see those countless 2-mile long coal trains leaving Montana and Wyoming every day and read about plans to greatly increase that flow of dirty carbon to Asia.

In moving on to the 4th and 5th columns, we see the basis for our relatively new and so-called “wonderful” prospects of the future energy independence that allegedly  promised by the development of our  unconventional sources of oil and gas. Again, the reaction of any intelligent and responsible person would be: what the hell – why are we bothering with the production of these more expensive and dirtier sources of gas and oil?  There is simply far too much of it already available and we can’t afford to use even the first one GtC that the unconventional sources provide.  Just how suicidal are we trying to be?  In short, we don’t need it and we can’t afford to use it.  All unconventional gas and oil must be left  in the ground.

At this point in this discussion one might wonder – why do we continue to use and export our coal?  And why are we seeking more sources of conventional oil and gas? And why are we developing unconventional sources of oil and gas? Besides insanity, what are the driving forces for these activities.  That reason is obvious, is it not?.  All of these activities are for the short term financial benefits of some – while we simultaneously screw young people and future generations.  So while the Chevron and  Exxon Mobile Oil commercials show how the developments of unconventional oil and gas in North Dakota are helping communities in that state build new and better schools, those ads do not mention the dire future the students of those schools will face a few decades hence.  If continued, the business-as-usual course is sure to provide our heirs with the distinctly rotten fruits being produced by this sort of labor.

There is only one way that mankind  can prove it is not so utterly stupid and shortsighted as to remain on its present course.  Obviously, that would be to limit his future use of fossil fuels to the available conventional sources of oil and gas and even leave about 100 GtC of that in the ground – along with all remaining sources of coal and unconventional oil and gas.  Whether or not mankind is capable of doing  that is the question. I provided my own guess in my previous post.

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