Greens would like us all to believe that our planet's carbon reserves (oil, coal, etc) will run out a week next Tuesday.
The truth is very different as this explanation reveals.
The BP Statistical Review of World Energy 2001, a definitive account of worldwide status.
No longer available on line.
Current Version: Statistical Review of World Energy 2005
The key figure is the R/P one of "227" years in the last column; it is the "Reserves / Production" ratio, i.e. the length of time the current reserves (see definition below) will last at the current rate of annual production.
Total up the other carbon sources and you will get something like 500 years. The National Coal Board used to claim something like 450 years for UK coal, although the British Geological Survey thought it considerably less — they were proved right.
The World R/P ratio for oil is 40, but for some countries (e.g. UK) it as low as 5 — but a key point to note is that this ratio hardly changes over many decades.
A key concept is to understand what 'reserves' means — non-specialists can have a major misunderstanding about it.
It normally means:
"known to exist, AND to be technically AND economically recoverable at the present time"
Some consequences of the definition:
How long can that go on for, how much oil is there ultimately?
- The oil industry is dated to Colonel Drake's Well in about 1880 (though there had been the odd oil well thousands of years before — the Chinese could get to thousands of feet around then).
Before Colonel Drake's Well there were no oil reserves in the world — because none were 'known to be technically and economically recoverable'!
Similarly, before the first UK oil well in the early 1960's the UK had no oil reserves, and its R/P ratio was 0/0.
- When the UK closed its coal mines in the 1980s-1990s the UK coal reserves massively slumped (even though the coal remained in place) — because although known, and technically recoverable, they were no longer economically recoverable.
The same thing happened to UK tin about 1880, when most UK mines closed within about 5-10 years because of cheaper tin from Malaya — the tin is still there, it is still technically recoverable, but it is not economically recoverable, so UK tin reserves are now negligible.
- Perhaps the most important point of all to grasp:
Although the UK R/P ratio is 5, it has been at about that level throughout its 40 odd year history! In fact that is a great improvement over its starting point, which was 0/0. The same goes for the World R/P.
How come the R/P ratio could stay at 5 over 40 years?
Answer: we keep finding more oil at about the rate we use it, and we improve the technology to find it in more difficult places, and we improve the technology to make it cheaper to recover, so every day we add new reserves (oil known to be technically and economically recoverable at the present time).
We don't really know, though there are various models (e.g. 'creaming curve theory') that do give predictions.
The practical answer is 'How much do you want there to be?', which relates to 'How much are you prepared to pay for it?'.
You pay enough for it, and we could perhaps keep the oil R/P ratio at 40 for a couple of hundred years, but there is no point in expending money looking for it now because we can't be sure you will want it beyond about 10 years.
However, the general pattern is that oil will be substituted by a cheaper energy source, and that masses will be left
in the ground (like UK coal & tin) — the Stone Age didn't end because we ran out of stone, but because something better came along.
The Stone Age didn't end because we ran out of stone,
but because something better came along.