Key Concept | Peak Oil | Reserves and Resources


Proven Global Oil Reserves. Image: CIA Factbook, 2009

In the previous peak oil article (#4 – Economics, Geology, and Technology) we studied the effects technology had on increasing oil reserves and accelerating oil depletion, as well as the differing views of geological versus economistic outlooks regarding peak oil. In this article we’ll analyse an issue which ties in closely to the previous one, that of oil reserves and oil resources.

Oil reserve definitions are complex and there is no universal definition for classifying reserves, a fact that can cause ambiguity in public data concerning oil supplies. One definition is simply “commercially exploitable oil that is in-situ”. BP defines them as the following:

“…proved reserves are those that have a probability of 90 percent: percentage of the reserve likely to be extracted during its lifetime, given current technological and price conditions. Those are designated as P90. Recoverable reserves that have a ‘better than 50% chance of being technically and economically producible’ are designated as probable, P50 (or ‘indicated’). Finally, possible (or ‘inferred’) reserves (P10, P20) are those that have 10 or 20 percent chance of recoverability under prevailing conditions. Estimates of total world reserves (of conventional oil) change depending on which probability one assumes in the analysis…” [x]

P90 reserves are also known as 1P. P50 are sometimes known as 2P (proven and probable reserves) and P10/P20 as 3P (proven, probable, and possible reserves). According to the Energy Watch Group the lack of a universal definition for reserve reporting  is responsible for the differences in published reserve data.

In comparison a resource tends to be an estimate of the amount of oil in a region which is neither commercially exploitable or technically feasible to extract. The International Energy Agency (IEA) classes a resource as:

“volumes that have yet to be fully characterised, or that present technical difficulties or are costly to extract, for example where technologies that permit their extraction in an environmentally sound and cost-effective manner are still to be developed.” [x]

Such resources include unconventional supplies of oil such as shale oil, tar sands, and Venezuelan “heavy oil” that are difficult to extract and have huge environmental costs.

The issues surrounding reserves are resources are important as ultimately they can affect the timing of peak oil, and confuse people into thinking that the updating of oil reserves equates to more oil being found:

“Since proved reserves (except for the Middle East exceptions) are much smaller than the initially anticipated proved and probable reserves, over time a re-evaluation of proved reserves is taking place because in the course of producing an oilfield probable reserves are converted into proved reserves. This practice creates the illusion of growing reserves despite growing consumption.

The term “reserve growth” is a somewhat misleading metaphor. In reality, of course, each barrel of oil burnt irreversibly reduces the original reserves on earth. Just our knowledge of remaining reserves is subject to change. An upward revision of our knowledge of reserves does not increase the actual amount of reserves.” [x]

In truth reserve growth or the conversion of resources into reserves is unlikely to make a significant impact on the timing of peak oil. As the UK Energy Research Centre (UKERC) calculated, increasing global reserve estimates “by one billion barrels delays the date of peak production by only 4.7 days”, and that “the discovery of resources equivalent to those of the entire United States would delay the global peak by less than four years”.

But what about the impacts of peak oil? Whether oil reserves grow or unconventional sources come online, oil is a finite resource. It will run out. As Thomas Keefer states:

“With global agriculture, transportation, industry and military capabilities heavily dependent on oil, and with no ready alternative as yet available to the fossil fuel energy regime, the implications of peak oil are not merely technical in nature, but profoundly social…” [x]

How will energy-intense societies cope with less available energy for their economies? How substitutable is oil for our economies? Can renewable energy plug-in the gap left by oil? These questions will be answered in the next article.


How does the Amazon support so much life? Is it due to soil fertility?

The beauty of the Amazon rainforest.

Now we have discussed the causes of deforestation in the Amazon and its consequences, I shall take a look at how the Amazon can support so much life. The answer may surprise you; the Amazon really ISN’T all that fertile and I shall explain why below.

The majority of soil in the Amazon is in fact very thin and acidic,and to be technical is called latosol. Due to high rainfall any nutrients are quickly washed away. 1 So the question is, how can an infertile soil support the high biodiversity found in the rainforest? There are several reasons:

  • Plant matter and dead animals decompose quickly due to high humidity and the ability of the decomposers to recycle them back into the ecosystem.
  • This ability to recycle also means nutrients rarely leave the rainforest ecosystem unless disturbed.
  • Most of the trees are short rooted so can take up nutrients in the top layer of soul quickly They also require buttress roots to hold them up, which are an iconic image of rainforests.

Buttress roots

So really the fertility is all down to really efficient nutrient cycling! 2 This means that when people start to farm in the Amazon, they find that the soil very quickly becomes infertile. The nutrient cycling simply becomes nutrient depletion, as all the crops do is take from the soil. Exposure to the sun also saps the soil of moisture turning it into a hard clay. 3

However, there are areas of the forest that are very fertile. The reason for this is ‘terra preta’, a different type of lathosol. 4 Terra preta is a very dark earth found in the Amazon and is entirely man made and very old. The soil was created by burying animal bones, manure, charcoal and pottery shards to creat biochar. Most importantly, compared to the few centimetres depth of the lathosol type above, terra preta can be up to 2 metres in depth.

Terra preta soil.

The depth and high density of carbon in the soil is what makes it fertile, the charcoal preserving organic matter to keep nutrients in the soil for use at a later date. Our ancestors used their waste in order to provide a highly fertile soil where they could grow crops. Or do they? Most think that it’s too convenient for them to have thought about creating this soil on purpose. Instead terra preta is simply the remains of kitchen rubbish, with charcoal used to fertilise soils they used for growing crops. This crop growing soil is called terra mulata. 5 Nonetheless areas from 20 hectares to 360 hectares of terra preta have been reported, and my cover up to 10% of the Amazon. 6 7 Maybe we could use these findings to help us create more fertile soil elsewhere? Thoughts and knowledge about terra preta are still in their early stages. More reading about terra preta can be found here:

This post concludes the last of three on the Amazon. They aren’t all encompassing, but they do give an insight into how the Amazon rainforest functions, what problems it faces and why.


Hi all, my name’s David

Hi all, my name’s David

I thought I’d use my first post to briefly introduce myself as one of the writers for this blog.


I’m a 22-year-old dreadlocked nature loving Christian, and I graduated with the same degree as everyone else this summer. I’m now living back home with my parents in Swindon where I’ve managed to get a job on the sales team at Currys, not quite the world-changing career path I know, but it’s a job and a job that I enjoy. Maybe I’ll write a post one day about working in retail and how it relates to fighting the biocrisis!

It gives me the flexibility to look for something more career-related on my days off. When people ask: “So David, what do you want to do with your life?” I direct them to the film (and book) ‘We bought a zoo’ starring Matt Damon and Scarlett Johansson based on the true story of Benjamin Mee at Dartmoor Zoo – just without the dead wife.

I’m still working out what saying “I’m going to live on a zoo” really means. And how it ties together with my other interests in urban agriculture, sustainable buildings, social enterprise, and the circular economy. The longer title I give is “A wildlife and sustainability park that focuses on UK conservation”. I think there is a lot to admire about wildlife in the UK, and the prospect of a fully self-sustaining educational facility that’s been designed from the ground up to provide its own food, water and energy really excites me. It would be great if I could make a buck or two out of such a radical enterprise but as long as it can promote and enhance local wildlife AND the local community then fantastic.

As you may very well have picked up, I’m very idealistic and have a lot of stuff going round in my head. One day I might put my thoughts into words through the medium of this blog, unfortunately I’ve just been too busy to really commit as much stuff as Grace and James, I’ll try and aim for a post every three or four weeks on average.

In my down-time I play PC games, my favourites at the moment are SimCity and the Sims because I enjoy designing houses and eco mega-cities, I’m buying a playstation 4 in the new year. I play a few musical instruments ranging from the tuba to piano, although I’m out of practice on all of them!

Anyway, nice to meet you all, peace out, god bless, safe, TTFN

What are the effects of deforestation in the Amazon?

Deforestation is far more widespread than just the Amazon. This image shows its effect on the landscape in Madagascar.

I have already covered the causes of deforestation in the Amazon in a previous post, so here I shall cover its effects. The main effect of deforestation you hear about is climate change, but there are many others. Below I briefly outline the main effects, but don’t forget they aren’t mutually exclusive. At the bottom of this post you will find links where you can read more around each of the points if you are interested.

1. Climate change.
Rainforests act as sinks for carbon, and with their destruction they can turn into carbon sources as the trees are burnt and plants decompose. 1 A reduced sink for carbon, means an increase in carbon in the atmosphere contributing to climate change and global warming. The Amazon is actually experiencing droughts due to the warming. 2010 was a severe drought year, with much forest dying back and the Amazon becoming a net emitter of carbon dioxide. 2 In the warmer, drier climate trees struggle to take up as much. 3 Rainforests can also take up a miriad of other greenhouse gases. They fully deserve being called the ‘lungs of the Earth’.

2. Soil erosion.
The removal of trees means there are no longer roots to hold the soil in place. The first instance there is rain, which funnily enough is a very common occurrence in a rainforest, it starts to wash the soil away downstream. Consequently as there are few or no plants to absorb the water, there is more surface run-off which increases the chance of flooding.

The left stream is full of sediment as a consequence of soil erosion. The right stream is how it should look.

3. Loss of biodiversity.
With the loss of trees comes the loss of the plants that live below its canopy, and all the animals that depend on it to survive. This is no small number as rainforests are one of the most biodiverse places on Earth with new species constantly being found. By destroying these rainforests we could in fact be destroying as yet unknown cures for illnesses. Projections suggest that 5–18% of endemic (i.e. occur nowhere else) mammal species will be extinct by 2020. 4 This may have a cascade effect where these species underpin the ecosystem, directly causing the extinction of further species. Do we even have the right to deprive a species of the right to survive? 

4. Water table disruption.
The removal of trees leads to reduced water retention in the soil, lowering the water table. This leads to dry and less fertile soils, making it hard to grow crops. Therefore the people who have deforested the land to farm, end up with pretty rubbish growing conditions. In fact the more they farm, the less fertile the soil becomes, however that shall be covered in the next post on the Amazon.

5. Loss of culture and land by indigenous people.
Indigenous people often don’t have any official rights to their land, therefore the government has no qualms about selling it, for example, to oil companies. 5 This obviously is a contravention to their human rights, but all the government wants is money. 6 They simply don’t care about the people who lived their first. Without changes the sale of land for oil will be disastrous for the indigenous people. 7 The destruction of the forest takes away their home, they are forced to integrate into a society where they more than likely don’t speak the language, and hence can swiftly lose their traditions. Medicinal plants they use may also be destroyed along with the forest, and there are loads left for us to discover, or at least there are at the moment! 8 In fact the government should be thanking these people, as they are actually the reason why the Amazon is so fertile (again to be explained in my next post). 

Indigenous people using their bodies to help raise awareness of how bad the situation is in the Amazon. Source: Amazon Watch

One of the big reasons I think most of the world is in denial about deforestation, is you have to see it to believe it. To get a sense of scale of the problem, the mouth of the Amazon alone has an island the size of Switzerland in it. 9

I know that this subject can be a somewhat depressing one, so I will leave you with an inspiring TED talk by Willie Smits discussing how we can restore rainforests.

The next post will be on terra preta, the reason why the Amazon soil is so fertile.











Key Concept | Peak Oil | Economics, Geology, and Technology

Image: Richard Masoner

In Peak Oil article #3 we discussed the differences between conventional and unconventional sources of oil. This article will focus on the role of technology in “opening up” new oil sources, and how the peak oil debate often devolves into a conflict of economics vs. geology.

Technology tends to be the main factor in whether an oil deposit can be exploited or not, usually determining whether oil is conventional or unconventional and thus increasing the amount of oil readily available for society. But Robert Hirsch (author of the Hirsch Report) demonstrated in 2005 that technology was not able to offset declines in oil production. Using data of the Contiguous United States oil production he found that despite “large improvements in oilfield technology, including affordable 3D seismic imaging, low-cost directional and horizontal drilling, greatly enhanced geochemical understanding, dramatically improved geological modelling, etc” production declines continued.

Oil Prices and Oil Production in the Contiguous United States [x]

Oil Prices and Oil Production in the Contiguous United States [x]

Additionally new technology for oil extraction and production may simply exacerbate the problem “by increasing production rate and depletion without increasing rates of discovery and replacement“. Improved technologies may “temporarily maintain production at the expense of subsequent more rapid decline” and “increases resource supply and decreases the resource price for a while but results in sharply higher prices in later periods because the resource is exhausted faster than it would have been without the new technology“.

Technological advance masks impending production declines [x]

Technological advance masks impending production declines [x]

It goes without saying that a steeper production decline means less time for society to adapt to a post-peak world, and thus “could have unpleasant effects on the economy“.

Speaking of economics, it is often posited in the “economical” view of peak oil that scarcity of oil supplies will drive market signals, triggering technological development and exploitation of previous uneconomical resources and eliminating the danger of peak oil. They often argue that the “allocative and dynamic efficiencies of the market” will present solution because “as oil becomes scarcer, its rising price will encourage innovation and technology to develop alternatives“, and that “scarcity is a relative, not absolute, concept and that there is nothing unique about any particular productive input, including petroleum” (or as geologist Kenneth Deffeyes said, “The economists all think that if you show up at the cashier’s cage with enough currency, God will put more oil in ground“).

In comparison, the geological view is absolutist, emphasising physical limits, especially those regarding laws of energy and thermodynamics:

“According to the geological view oil reserves are ultimately finite, easy-to-access oil is produced first, and therefore oil must become harder and more expensive to produce as the cumulative amount of oil already produced grows…the recently observed stagnant oil production in the face of persistent and large oil price increases is a sign that physical scarcity of oil is already here, or at least imminent, and that it must eventually overwhelm the stimulative effects of higher oil prices on oil production. Furthermore they state, on the basis of extensive studies of alternative technologies and resources, that suitable substitutes for oil simply do not exist on the required scale and over the required horizon, and that technologies to improve oil recovery from existing fields, and to economize on oil use, must eventually run into limits dictated by the laws of thermodynamics, specifically entropy.” [x]

Or to summarise, “Geologists explain peak oil as an inevitable geological phenomenon. Oil was created in a process taking millions of years, and reserves are not being added to. Although the precise scale of total recoverable reserves is hard to know, their finite nature is certain.” It is clear to see the great divide between the two sides of the issue, but it is important to identify bias or vested interests when attempting to explain peak oil. For example, forecasts of future oil production will be optimistic when made by governments or multinational oil companies whose survival is tied to steady production increases, whereas pessimistic predictions are usually made by independent analysts. “Official” forecasts made by institutions such as the International Energy Agency or US Energy Information Administration will also tend to “project that plentiful oil supplies will be available, that supply will balance with demand” compared to more pessimistic outlooks informed by independent petroleum geologists. It is interesting to note here that a report commissioned by the International Monetary Fund states that, although their final views are not as “pessimistic” as geological arguments, there are definite “resource constraints” on future oil production and that peak oil is “uncharted territory for the world economy”.

Recent evidence that seems to confirm the geological view over the economic view was presented by James Murray and David King in the journal Nature, where they showed that despite price increases (and thus increased demand) oil production reached a “cap” where oil production did not increase regardless of price.

Oil Production Hits a Ceiling [x]

Oil Production Hits a Ceiling [x]

In the next Peak Oil article we’ll look at the issues of oil “reserves” versus oil “resources”, and how that can affect the timing of peak oil.