On her blog “Our Finite World,” Gail Tverberg has provided a summary of the current state of the world’s oil supply, and how the idea of peak oil fits with the facts. In this article, she included the following graph and commentary:

[begin excerpt from Tverberg article]

By fitting trend lines, we can see where oil production seems to be headed:

World Oil Production With Trend Lines

What we can see from Figure 7 is that the growth rate of world oil supply has gradually been slowing. The growth rate was highest in the 1965 to 1973 period, at 7.9% per year. Then we hit the “oops” period of 1973 to 1975, when we ran into conflict with OPEC regarding oil supplies. The trend rate dropped to 3.9% in the 1975 to 1979 period. Between 1979 and 1983, oil consumption dropped to a -3.9% per year, when we picked some of the low hanging fruit regarding oil usage (mostly by eliminating petroleum from electricity generation and downsizing automobiles). The trend between 1983 and 2004 shifted to +1.5% per year, and since 2004, seems to be about +0.2%.

. . .

Looking at Figure 7, it looks like the “trend” in trend rates over time is down. In the absence of other information, we would expect production to remain at its recent trend rate of 0.2%, or alternatively, the trend rate could take another step downward, probably to an absolute decline in oil production. A recent announcement from Saudi Arabia suggests that its ability to offset declines elsewhere in the future is likely to be virtually nil, so a continued decline in production from the North Sea and elsewhere will need to be made up with new production elsewhere, or will lead to a worldwide decline in oil production.

[end excerpt from Tverberg article]

I consider this a very useful way to understand the facts of world oil production. We do not have the mathematically smooth bell curve of Hubbert’s peak oil predictions. Embargos, revolutions and wars for oil have broken the historical record into succeeding phases of development. At times we can see temporary declines on the path to new record levels of production. Newly discovered oil fields or new technology in drilling have sometimes more than compensated for the decline of old fields. We can see temporary peaks that have been surpassed. Then as decades progress, new fields become old ones and their rate of production declines.

Out of all the details and and reversals due to political conflict, we can still see the general pattern imposed by depletion. As Gail has poiinted out, the trend in trend rates is down. Without relying on any theory at all, but simply by looking at the record, we would expect the next phase after this decade’s very slow increase in the volume of production would be a slow decline.

If the graph were to be redone in terms of net energy instead of the raw volume of production, this decade’s slow increase would already show as a decline. By simply showing raw volumes, the graph as presented allows double-counting of some oil. this double counting would be corrected by measuring net energy.

However, good historical data does not exist that would allow this imagined chart to be presented with any accuracy. Good data does not really exist in the public domain for today’s production, let alone production from 30 or 40 years ago. Oil companies keep the detailed data secret as much as possible, and national oil companies which produce most of the oil have even more ability to keep secrets than corporations such as BP and Exxon-Mobil.

If the graph were to be redone in terms of raw volume per capita, it would be obvious that the trend has been negative for decades.

We could of course have a long academic discussion about the relative significance of the raw volume peak, the net energy peak, and volume per capita peak. A transition group is more inclined to leave that discussion to academics. For transition organizing, it should be enough to understand we are already experiencing less energy per person, and we expect this to more obvious in the future than it is already.

Those are the facts. Our focus is on what we should be doing locally to adapt.