I remember seeing that sudden spike in population. I had just seen a museum display on the bog people. They lived several thousand years ago and had all the basic tools that you would expect from any with a pre-industrial level of technology. A ranged weapon, a hand to hand combat weapon. Clothing. AND surprising to may anyways a money pouch with little hammered fragments of gold. They were not fashioned into coins. They were more like small gold nuggets that had been hammered flat and has all the corresponding imperfections and splits that you would expect from such a simplistic process.

It drove me nuts. Why? Why did human population suddenly spike like that? For thousands of years we were under a billion. We always struggled with famine and starvation. There were small incremental population gains over time, but never anything like what we have seen since the 1800's.

It took me a couple of years and I think I finally found it. It was the discovery of how to use oil. I have seen historic references to oil use at other times in history, both in european and asian accounts. But the use was very limited. It was a flamable substance that could be burned and was used in war. (coat a battle field with oil then ignite it. In an asian account they threw containers with oil onto the enemy and then sent flaming arrows)

The discovery of oil in .... 1867? in Pennsylvania changed everything. Oil was then used for internal combustion engines and the mechanical devices that turned the flammable substance into work was a MASSIVE change.

Follow up on peak oil. There are lots of argument about peak oil. Are we at peak? Is it really a non-renewable resource? (especially since we know algae ponds can produce massive amounts of oil from very small physical space and with very little in the way of inputs) Peak oil does do a very good job of explaining how our dependence on oil has evolved, how central oil has been to war in the last 100 years and the concept of energy slaves.

If you were to calculate in calories or joules how much energy a human can produce, then look at how much a human in western society consumes (food production, food transportation, air conditioning, water heating, heating our homes, driving to work, etc) then if memory serves me right we all have the equivilent of 44 energy slaves.

Any time any population (two examples I remember seeing are bacteria in a petrie dish and deer on a previously unoccupied island) is given a virtually unlimited energy source, their population explodes until they hit the peak of extraction. That's the basic concept to peak oil. Not that there is no more oil, it's just that our ability to increasingly extract and use more oil every year has come to an end. We are at the peak and stay on the plateau of the bell curve. If ever we slide down the other side (depletion) then we are looking at a civilization ending event.

Imagine instead of looking at a 4% gdp growth next year, and a 3% growth the year after, we are looking at a 7% gdp decline annually for the foreseeable future. That's the crisis of peak oil.

Also of note; when looking at energy per capita globally; we see that we hit the maximum amount of energy per person back some time in the 1950's to 1960's. That is why standards of living were so much better back then. Each person had a larger amount of energy they could consume. Ever since then, while we as a species consume more oil, there are more of us and as a result it is less per person.

The United States hit peak in domestic oil production in .... I think it was 1970, but this was offset by the use of the petro dollar. So while US oil production was in decline, America had access to all the oil it wanted because all global trade in oil was in US dollars. The was in Lybia was (possibly) the result of Quadaffi saying he wanted to stop using the us dollar in his oil trade and wanted to come up with a gold backed dinar. The invasion of Iraq was preceeded by Saddam saying he wanted to change the UN oil for food program away from dollars to Euros; three months later the invasion began and Saddam was deposed. Now look at recent news. Up until the last few years the petro dollar dominance remained. Then we started to hear about bilateral trade agreements between oil producers (nations) and oil consumers (nations) that would be done in currencies other than the US dollar. This is a seismic change in world geopolitics.

The former USSR hit their peak oil in the late 1980's, and then the wall fell.

Oil is a massively influential resource.

Even the trucker protest in Canada. Before going after the bank accounts, they went after the jerry cans and stopped people from bringing fuel to the truckers.