How much fossil fuel is left?

I keep reading that fossil fuel is going to run out in our life time, yet no one seems to be really doing anything about it.

And, I read in a recent article that Sudan might have as much unextracted fossil fuel as Saudi Arabia. And then there are many other countries with huge potential reserves. So it seems like fossil fuel will last longer.

Even though I know oil is supposed to come from dead dinosaurs, how does it work in laymen’s terms? It doesn’t seem possible that you could just compress organic material over time and get oil. And where did all these dead dinosaurs come from? When they died, didn’t they become part of the food chain? When Brontosaurus dies it’s supposed to be T Rex’s breakfast and not Chevron supreme, right?

My guess would be that at least 99.9% of all oil comes from plants and microscopic organisms. The dinosaur part would be very, very small.

But that is basically how you make oil. It’s a fairly simple process to chop down a few plants and make oil from it and although it costs more to manufacture than to mine, the world won’t come to a grinding halt if we run out of fossil oil.

That we have enough to last a little more than 50 years at our current consumption rate. Long before that time though, automobiles will have been developed that rely on different methods of propulsion, from hydrogen, to electric, or maybe even something we have never dreamed of yet.

So in other words, by the time it happens, it won’t be much of a concern at all.

It is my understanding that when calculations are made for how much fossil fuel there is remaining they only take into account what is accessible at the current time, not what may be accessible in the next few years. That means those figures are not even worth the paper they are printed on.

My 4th grader came home last year with the doomsday sayings of his 3rd grade teacher about how we were going to run out of fuel soon and Squid went ballistic because basically we haven’t even begun to tap tremendous amounts domestically(!), let alone off-shore and foreign sources. Alternative energy ideas should revolve around efficiency and pollutant factors, not some fear-mongering idea of a possible shortage.

::grumbles off to the gas station to pay waaay too much::

If you count hydrated methane deposits on the ocean floor (resulting from bacteria), then we’ve barely scratched the surface of our burnable fuel supply. Not sure if this counts as a fossil fuel though.

Well, before I post the numbers, here are the short answers:

  • Coal, we have hundreds of years of - maybe 300 to 400.

  • Oil, things don’t look as good. Maybe 25-50 years before we start getting scarce?

  • Natural gas looks better, much better than oil. Maybe 50-80 years?

Let’s look at what the best estimates available from the Department of Energy (DoE) are on both the US reserves of fossil fuels, and the consumption of fossil fuels.

First, my favorite, coal:

Coal: As of January 1, 1997, the US had approximately 507,739.7 million short-tons of coal in reserves. Our consumption in 1997 was 1008 million short-tons, with an additional 1 million short-tons imported for coking purposes mainly. For a total of 1009 million short tons.

Overall, coal reserves are decreasing at a rate of about 0.3% per year.

Crude Oil: As of 12/31/1998, the Proved Reserves of crude oil in the US were 21,034 million barrels (1 barrel being 42 US gallons). Our consumption of crude oil in 1997 was 6,796 million barrels of crude oil. Now, at first that looks bad. However, most years we continue to find and add reserves, so the overall drain is less. It is interesting to note that in 1998 we saw a decline of about 7% in our overall reserves, which was an unusually low year. In prior years, from 1988 to 1998, US reserves of crude oil declined at an average rate of about 2% per year. It is expected that this 1998 trend was a unique phenomenon, and that the 2% trend should hold for many years to come.

Natural Gas: As of 12/31/1998, the Proved Reserves of natural gas in the US from all sources were:

Dry natural gas:                 164,041 billion cubic feet
Wet natural gas:                 172,443 billion cubic feet
Non-associated natural gas:      141,783 billion cubic feet
Assoc. Dissolved natural gas:     30,660 billion cubic feet
Natural gas liquids:               7,524 million barrels
Natural gas plant liquids:         6,188 million barrels
Lease condensate:                  1,336 million barrels
  in Non-producing reservoirs:       530 million barrels
Coalbed methane:                  12,179 billion cubic feet

Note that volumetric gas measurements are measured at STP for gas, which is 14.73 psia, 60 F. And 1 barrel is equal to 42 US gallons.

The overall consumption of natural gas in 1997 was 21,972 billion cubic feet, dry basis. The overall decline in reserves follows a trend of about:

Dry natural gas:                 2% decline
Wet natural gas:                 2% decline
Non-associated natural gas:      1% decline
Assoc. Dissolved natural gas:    5% decline
Natural gas liquids:             6% decline
Natural gas plant liquids:       7% decline
Lease condensate:                1% decline
  in Non-producing reservoirs:   6% increase
Coalbed methane:                 6% increase

So, how do we interpret the numbers? You have to look at many things here:

  1. What is our rate of growth in energy consumption?
  2. What happens as nuclear plants come to the end of their life cycle, and are shut down?
  3. Will reserves keep decreasing at the same, relatively slow rates?
  4. What is the cost to recover these reserves?
  5. What is the penalty we will pay in terms of pollution, esp. w.r.t. CO[sub]2[/sub] emissions?

Any questions so far, or discussion topics? Since there are so many things to cover, I think it’s best to see if there are any, and focus on those.

PS: I hope I’m not double-counting in the gas reserve numbers somehow. I’m not a Gas Gal after all, just the Coal Queen. :slight_smile:

Anth: What about the new theory SciAm was talking about a few months ago? About how oil is held below the earth’s crust and ‘bubbles’ to pockets in the crust occasionally? Does that hold any credibility?


Well, I just would love to give you the Straight Dope on that.

But I cannot, as I know very little about it. However, I work with an expert in those things, and I’ll e-mail him and see if he has any relevant thoughts.

Was this a theory put forth by Russian scientists?

This theory was proposed by Thomas Gold about 15 years ago. The basic idea is that when the Earth was formed, it included a lot of organic material in carbonaceous chondrites (which make up several percent of all known meteorites). This material was then ‘cooked’ in the Earth’s interior and then some small fraction of it rose up to the surface, and some small fraction of that was trapped as natural gas, of (after bacterial action) as petroleum.

For a long time this hypothesis was ignored, but several tests of it have shown support for it. The main test that I am aware of was a drill-hole in central Sweden, in the "Siljan Ring’ IIRC, which is an ancient meteor crator located in volcanic/plutonic rock, where no hydrocarbon at all should be found. What was found was small amounts of natural gas, and that the deeper the drill-hole the greater the amounts. In addition, ‘black muck’ was recovered, which when analysed, turned out to be bacterial in origin.

More information can be found here.


It also depends what sort of fossil fuels you are talking about. AS part of a tour I took last year in Venezuela we went to a petrol refinery and a petrol research institute (the things you do to get a free ticket to Venezuela), but they were saying that Venezuela has enough heavy crude oil to supply the world for the next 200 years. They have found some ways to get the combustion rate up and make it easier to process (stuff with surfactants and emulsifiers and water). They claim that it is easier to work with than the current oil (it doesn’t need to be cracked), but of course it requires a different style of engine delivery system and so on.

But they probably wont market it as such - who wants to put asphalt in their car? Imagine the slogans, ‘If it’s good enough for the road, it’s good enough for the road’ :slight_smile:

Of course, the books are not anywhere near me so I can’t really expand on this.

Heh heh…I think you are talking about Orimulsion, a topic I just happen to be an expert on.

Yes, it is true that Venezuela has huge amounts of Orimulsion (marketed as “Orimulsion-400” around the world). Orimulsion is aa mixture of 30% water, 70% heavy bitumen, and really neat emulsifiers and additives to keep the whole thing together. In fact, there is a 1-gallon jug of Orimulsion-400 sitting in my garage right now as I type! (aren’t I the lucky gal?)

I posted back in July that there are an estimated 270 billion barrels of economically recoverable reserves of Orimulsion produced from these bitumen deposits in Venezuela alone (according to Bitor PdV S.A.), with total reserves listed at 1.2 trillion barrels. Compare these numbers to ones I listed above for crude oil reserves - for the US, a total of 21,034 million barrels.

True, use of Orimulsion as a motor fuel directly has been relatively unsuccessful, and only Warsilia is actively working on it. But it can be cracked into lighter products, but at significant cost. Venezuela is spending a lot of research Bolivars to try and make some way to cheaply convert the bitumen into oil. No real luck yet, but you never know…

Anthracite, you got me curious:

Do you know how much usable “oil” you could get per barrel of “Orimulsion”? Or, do I interperet your post as that they haven’t done it at all yet? I guess what I am wondering is this. If it takes something like 100bls of Orimulsion to make 1 or oil, what would the use of it be? Or is it so far in the future its just a guess?

I bet Anthracite and FloChi are a real gas at parties :wink:

My info on this is a little out of date - about a year old. Ugh. Anyhow, my understanding is that you get about 40-50% yield per barrel - that is, 1 bbl of Orimulsion can make 0.4-0.5 bbl of oil. However, that oil is already somewhat refined, so it’s yield is higher than a typical barrel of raw crude. But it’s in that range somewhere.

Yes, it has been done, but at a cost (I believe) of about $350 per barrel. So it has a long way to go. Which is why diesel companies are trying to make engines that use it directly, like Warsilia.

Anthracite wrote:

Waaaaaait a second … when I was taking undergraduate chemistry, STP meant 1 atmosphere pressure and 0 degrees Celsius. 0 Celsius would be 32 F, not 60 F.

I don’t think so, tracer. Way back in my thermodynamics classes, we used 290°K, which approximately equals 62°F (or 17°C), for calculations with STP. I forget what it was in degrees Rankine, a bit over 500°R, if I recall rightly.

Yes, 0 Celsius would be 32 F. However, in the natural gas industry in the United States, STP is often defined by tradition as being at 60 F. It is normally 32 F for most other circumstances.

I forgot about this old thread…


I recently heard on the news again that Alberta (where I live) has as much proven and recoverable crude oil reserves in the form of tar sands than Saudi Arabia. I did a brief search on this and I didn’t find any firm, solid evidence. What do you (or anyone else here) think of that?

I really don’t know about the tar sand potential of Alberta, but I will make note that the Saudis’ current production is dominated by flowing oil wells. Recovering oil from a flowing well is economically vastly more efficient production than mining oil from tar sand, which is how you produce oil from tar sands.

Well bernse, depending on which source you believe, Alberta has between 280 and 330 billion barrels of recoverable oil reserves in the Athabasca tar sands NE of Edmonton. And a total reserves of about 820 billion to 1.1 trillion barrels. Pretty damn impressive. Some people claim that more than half of all the bitumen deposits on Earth are in the Athabasca deposit, but there is still much that is unknown about the true extent of that and other deposits, such as the Orinoco basin in Venezuela. There could be even more oil.

Now, supposedly Syncrude’s production costs were $14.95 a barrel in 1994, $13.69 a barrel in 1996. So it is economical to produce. The problem is twofold - production capacity and efficiency. In 1996, they were producing about 206,000 barrels per day of oil. HOWEVER - the process is very energy intensive. Supposedly, for every barrel of oil they produce, they use the energy of about 0.75 to 0.8 barrels of oil. Thus, they have a really low energy efficiency in recovering the oil. And thus, that 330 billion barrels quickly becomes about 75 billion barrels - pretty good, but not what the news is reporting.

Supposedly, you must mine about 1800-2300 kg of sands to produce 1 barrel of oil, and a large amount of the sands are under a huge overburden of rock, glacial tills, etc - sometimes hundreds of feet thick. Plus, the coking processes they use to refine the oil require a bit of energy as well. Thus, there are many different things that make the deposits interesting, but far from a cure-all.