Guest Post by Willis Eschenbach
In oil, as in other extractive industries, you have what is called the “R/P ratio”. In the R/P ratio, “R” is reserves of whatever it is you are extracting, and “P” is the production rate, the rate at which you are extracting and using up your reserves.
Figure 1. World annual oil production in billions of barrels (blue line), and years left at that production rate (R/P ratio, red line). Right scale shows the proven oil reserves for each year, in billions of barrels (dotted green line). DATA SOURCE: BP Statistical Review of World Energy 2011, a most fascinating Excel spreadsheet. PHOTO Spindletop Hill Gusher, 1901
When you divide the amount you have in reserves by the rate at which you are extracting the resource, you get the number of years the reserves will last at that rate of extraction. Accordingly, I include the R/P ratio in Figure 1 as “Years Left”
A couple of things to point out. First, the “Years Left”, the R/P ratio, is currently more than forty years … and has been for about a quarter century. Thirty years ago, we only had 30 years of proven oil reserves left. Estimates then said we would be running out of oil about now.
Twenty-five years ago, we had about forty years left. Ten years ago we had over forty years left. Now we have over forty-five years left. I’m sure you see the pattern here.
Second, this is only what are termed “proven reserves” (Wiki). It does not include “unproven reserves”, much of which is in the form of unconventional oils such as shale oil and oil sands. Even discounting the unproven reserves, while the rate of production has increased, the proven reserves have also increased at about the same rate. So the R/P ratio, the years left at the current rate of production, has stayed over forty years for almost a quarter century..
Now, at some point this party has to slow down, nothing goes on forever … but the data shows we certainly don’t need to hurry to replace oil with solar energy or rainbow energy or wind energy in the next few decades. We have plenty of time for the market to indicate the replacement.
Don’t get me wrong. I’d love to find a better energy source than oil. In fact, the huge new sources of shale gas will substitute in many areas for things like heating oil, and will burn cleaner in the bargain. And I do think we’ll find new sources of energy, humans are endlessly inventive.
I’m just registering my protest against the meme of “OMG we’re running out of oil we must change energy sources right now tomorrow!!”. It is simply not true. We have plenty of time. We have decades. We don’t have to blow billions of dollars of our money subsidizing solar and wind and biofuels. The world has enough oil to last for a long while, plenty long enough for the market to determine whatever the next energy source might be.
NOTE: Oil figures, particularly reserves, are estimates. Oil companies are notoriously close-mouthed about their finds and the extent of their holdings. The advantage of the BP figures is that they are a single coherent time series. Other data gives somewhat different results. As far as I know the increase in proven reserves despite increasing production is common to all estimates.