Oxford University Press's
Academic Insights for the Thinking World

How much oil is left?

The world’s total annual consumption of crude oil is one cubic mile of oil (CMO). The world’s total annual energy consumption – from all energy sources – is currently 3 CMO. By the middle of this century the world will need between 6 and 9 CMO of energy per year to provide for its citizens.

In their new book, Hewitt Crane, Edwin Kinderman, and Ripudaman Malhotra introduce this brand new measuring unit and show that the use of CMO replaces mind-numbing multipliers (such as billions, trillions, and quadrillions) with an easy-to-understand volumetric unit. It evokes a visceral response and allows experts, policy makers and the general public alike to form a mental picture of the magnitude of the challenge we face.

Here, Ripu Malhotra answers some questions we had about oil, energy, climate change, and more.

Q: What is the goal of your book, A Cubic Mile of Oil?

A: Raising literacy about energy in the general public. Meeting the global demand for energy is going to be a daunting challenge, and the way we choose to do it, namely the energy sources that we choose to employ will have a profound effect on the lives of millions of people. We have tried to provide an unvarnished look at the different energy sources so people can engage in an informed dialog about the choices we make. People have to be involved in making the choice, or the choice will be made for them.

Q: Why introduce a cubic mile of oil as another unit of energy? There are so many units for energy already.

A: True, there are way too many units of energy in use. Furthermore, different sources of energy are often expressed in different sets of units: kilowatt-hours of electricity, barrels of oil, cubic feet of gas, tons of coal, and so on. Each of these units represents a relatively small amount of energy, and in order to express production and consumption at a global or national scale, we have to use mind-numbing multipliers like millions, billions, trillions and quadrillions. To add to the confusion, a billion and a trillion mean different things in different parts of the world. It gets very difficult to keep it straight.

Q: Who coined the term CMO?

A: Hew Crane came up with this term. He was waiting in a gas line in 1973 when he began contemplating how much oil the world was then using annually. He made some guesses of the number cars, and the miles driven by each, etc., and came up with an estimate approaching a trillion gallons. How large a pool would hold that quantity, he next pondered. A few slide rule strokes later realized that the pool would have to a mile long, a mile wide and a mile deep—a cubic mile!

Q: What is your overall message?

A: Currently, the global annual consumption of oil stands at 1 cubic mile. Additionally, the world uses 0.8 CMO of energy from coal, 0.6 from natural gas, roughly 0.2 from each of hydro, nuclear, and wood for a grand total of 3 CMO. Solar, wind, and biofuels barely register on this scale; combined they produced a total of 0.03 CMO in 2008. The consumption of energy is by no means uniform around the globe; per capita consumptions vary enormously. Whereas CMO is a useful unit to describe global energy consumption, it is not convenient for talking about per capita consumption. We have chosen to describe per capita consumptions in gallons of oil equivalent, or GO units. in North America annual consumption of primary energy is about 2,000 GO; it is about half that in Europe and Japan; and the global average is less than 500 GO. In Asia, the per capita annual consumption is only 250 GO.

The challenge of supplying energy to the world’s population is really overwhelming. Even at a modest growth rate of 2%/year (corresponding to a doubling very 36 years), the world’s energy demand by 2050 will be over 7 CMO. The cumulative energy consumed in the first half of this century (2000 to 2050) is projected between 160 and 270 CMO. When we look at what it takes to develop an infrastructure capable of producing even 1 CMO of energy, we realize that here are no easy solutions, and it will take an enormous effort sustained over many decades.

The CMO unit allows us to dispense with those exponential modifiers, compare the different sources directly, and make meaningful choices. We also wanted to use a unit that could be appreciated by the public at large. A volumetric unit allows us to form a mental image, even though we may not quite get our arms around a CMO.

Q: So what would it require to meet the energy challenge?

A: An all-out commitment and perseverance to develop all our energy sources. Over the next 40-50 years we will need to develop energy sources that can deliver an additional 4 to 5 CMO annually. Consider for a moment what it takes to produce even 1 CMO/yr. It takes 2500 nuclear plants of 1 GW capacity to generate 1 CMO. If we choose to go this route, we need to be commissioning one nuclear plant a week for fifty years to get 2500 plants up and running. If we choose hydroelectric, and use the 22.5 GW Three Gorges Dam as an example, we will need 153 of those, or about one new Three Gorges Dam every four months for fifty years. The Sun, of course, bestows on us 23,000 CMO, but harvesting that energy will require an enormous effort. We need about 3 million 2-MW wind turbines, spread over approximately 600,000 square miles, to produce 1 CMO/yr. If we choose to go this route, we should be installing 1200 such wind turbines every week for fifty years. It takes 4.5 billion residential rooftop photovoltaic systems (2-kW ea) to produce the equivalent of a CMO/yr; in other words, a quarter million rooftop systems each day, everyday for fifty years!

In face of these realities, I think calls for turning off fossil energy sources that we use today in order that we can quickly power ourselves with renewables, or our income sources as we refer to them in our book, are irresponsible. We will need to develop, coal, and oil, and nuclear, and wind, and solar, and…AND is the operative conjunction, not OR.

Yes, we need to move away from inherited resources, but the replacement pace has to be commensurate with the global demand for energy and the technological and economic viability. Our inability to supply sufficient energy to the world means that we are condemning societies currently not using very little energy to continue living an impoverished existence.

Q: What about global warming and attendant climate change from the continued use of fossil energy? Do you not believe that greenhouse gases would cause global warming and drastic changes in the climate?

A: The greenhouse gas effect is real. It is well understood and were it not for the greenhouse gas effect, the average temperature of Earth would be a whole lot lower (about 0°F instead of 59°F). Global warming is also real. There is substantial evidence that the Earth has been warming about 1°F a century since the end of the Little Ice Age in the 17th century; a part of the warming is natural and there is a substantial body of evidence pointing to a role of humans in causing the remainder. The dire predictions for the future that we hear about are based on climate models. Many scientists—and not just the fringe, because among them are the members of the Intergovernmental Panel on Climate Change—have serious disagreements about various aspects of the model such that there is greater uncertainty about the predictions of future temperatures, and even greater uncertainty when comes to predicting its effect on the climate and sea level. Rather than get bogged down by this debate, we suggest that we start focusing on how we will provide energy for the world to prosper in the coming decades. Lack of sufficient energy also has dire consequences.

In the long run, our fossil resources will not suffice, and we must develop renewable energy sources. Because developing them to scale takes a lot of time, we need to look at ways to reduce future energy demand. If our concern is the build-up of greenhouse gases, then let’s focus on those actions that have a large impact by (a) reducing greenhouse gas emissions among the nations that use a lot of energy, and (b) minimizing the future emissions of nations that are currently using very little energy. Looked at this way, two imperatives emerge:

(a) Change our diet and move towards—or stick to—a vegetarian diet. The magnitude of the impact of our diet on energy consumption and greenhouse gas emissions was quite a surprise for me. I was generally aware of the varying footprints of different diets—there is a copy of Frances Moore Lappe’s Diet for Small Planet in my kitchen—but the fact that switching from a red-meat diet of 2000 Calorie diet per day to lacto-ovo vegetarian diet of the same caloric count could have an impact of saving about 300 gallons of oil per year blew me away. These savings are equal to switching from a 12 mpg SUV to a gas-sipping hybrid.

(b) Provide inexpensive renewable energy to the impoverished regions currently not served by the global energy network—regions with per capita consumption of 200 GO or less. Supplying even limited amounts of energy in those regions makes a huge impact on the quality of life of the people.

Q: Why are you so negative about the potential for your renewable sources to provide a significant fraction of global energy?

A: We are not negative, as we know they will eventually play important roles in our world energy economy. However, we sometimes doubt the claims from their developers about the rate at which these technologies will be deployed and their near term impacts – which, today, are generally negligible in our overall energy economy. That’s not so say that we shouldn’t engage in their development. It is precisely because it takes so long to develop new resources to that we sense the urgency and call our predicament a crisis. While many of today’s technologies for producing energy from income resources are inadequate, and plunging head-first into implementing them on a large scale is likely to be too expensive—that is, deprive resources that could be otherwise used by the society for its other pressing needs—and likely to also have deleterious side effects for the environment. We need many innovations to enable their widespread use; the innovations will not happen unless we start working on them, and the government should nurture their development through R&D and even demonstration scale projects.

Q: What about increased efficiency and conservation?

A: They are important ways to reduce the demand for energy, and yes we must implement measures to improve efficiency and foster conservation. Having said that, I should mention that the scenario leading to 9 CMO/year by 2050 has improved efficiency measures built into it. It is the business-as-usual scenario, but we have been increasing efficiency over the last forty years, and that rate of increasing efficiency has been baked into the projection. A dedicated effort on top of that is needed to cut the projected demand down to about 6 CMO/yr.

Historically, increasing efficiency has only had a limited impact in reducing total energy consumption. Although the appliances like refrigerators and TVs have become more efficient over the recent decades, they have also become larger. Likewise, the car engines have become more efficient, but the increases in car weight and performance have offset any gains in engine efficiency and the overall fuel economy has not improved. As we define the term, efficiency is doing the same thing as before but by consuming less energy. Conservation, on the other hand, requires changes in lifestyle that obviate the expenditure of energy.

Q: How much oil is left?

A: Global oil reserves are estimated to be 46 CMO and our current rate of consumption (1 cmo/yr). That does not imply that we run out of oil 46 years.

It is worth remembering that this ratio of reserves to current consumption rate has been around 40 for the last 60 years! The ratio does not give the time to exhaustion for two reasons. First, the consumption rate is not fixed; it has historically increased steadily and will likely continue to do so. The increased consumption reduces the time to exhaustion. The second reason has to do with how reserves are defined. Oil reserves are accumulations that can be extracted with current technology at current prices. Geologic accumulations that are currently inaccessible and/or uneconomic—our resource base—may become economic at higher prices, and/or with improved oil extraction technologies.

Estimates of our reserves plus resource base range between 56 and 140 cmo. Additionally, there are unconventional sources of oil such tar sands and shale oil such that our total endowment can be large as 400 cmo. Total endowment aside, a critical question that we face is whether we can continue to produce oil at the ever-increasing rates that the world is apparently demanding.

Q: Can we eliminate the need to import oil from the Persian Gulf through improved fuel economy?

Yes we can, but let’s also remember that the US imports from the Persian Gulf comprise only a tenth of our total consumption. This fact came to me as a surprise for I was under the impression that almost all our imports come from the Middle East. To gain some perspective, consider these numbers, all in million barrels/day:

US consumption 23
US production 10
Imports from
Canada 2.5
Mexico 1.3
Venezuela 1.2
Saudi Arabia 1.5
Rest of Persian Gulf region 1.0

The US consumes about 23 million barrels of oil every day while it produces only 10 million barrels. The remaining 13 million barrels are imported from a diverse set of regions, and only 2.5 million come from the Persian Gulf region, with Saudi Arabia providing 1.5 million of those. We import 2.5 million barrels a day from Canada, and another 1.3 million from Mexico. We get 1.2 million barrels a day from Venezuela—more than from Algeria, Iraq, Kuwait, Nigeria, or for that matter any country in the Persian Gulf region except Saudi Arabia. So now when I hear someone describe how by increasing the fuel economy of vehicles in the US we can eliminate the need of oil from the Persian Gulf, I know they are talking about reducing consumption by about 10%.

Q: You come out as a proponent of nuclear power. Why?

A: Of the various CO2-emissions free technologies for producing energy, nuclear is one that is most advanced, practiced at a large scale, and can be expanded substantially. Worldwide there are about 440 nuclear reactors with a combined generating capacity of over 370 gig watts (GW), and these plants generate power all the time producing about 0.2 CMO each year. Total generating capacity of wind and solar units is approaching 150 GW, but they produce only 0.02 CMO/yr. The levelized cost of electricity from nuclear power is between 5 and 7 ¢/kWh, which is comparable to wind power, but fourth or fifth that from photovoltaics.

Q: Aren’t the uranium supplies rather limited?

A: Yes and No. Global uranium reserves (at $59/lb-U) are about 3.5 million tons or only about 10 CMO, and if the nuclear power to be expanded to a CMO/year level, we would indeed exhaust them very soon. As with petroleum the resource base is much larger, and doubling the price of the ore increases the resource base ten fold. The cost of uranium is a small portion of the cost of electricity, and this doubling of fuel cost, which would increase the resource base to over 100 CMO, is estimated to increase the cost of electricity by only 1 ¢/kWh.

These estimates for uranium resources refer to the case when uranium is used in a once-through mode. The once-through mode leaves a lot of uranium and other fissile fuels behind in the spent rod. With fuel reprocessing, the same reserves could produce about two times, or more, energy. A major benefit of reprocessing spent fuel is that the volume of high-level radioactive waste to be stored is reduced to about a fifth, and the remaining radioactive materials, mostly fission products, decay relatively rapidly.

Once we start working with alternate fuel-processing schemes and breeder technologies, we will also be able to tap into Thorium-based nuclear power. Currently that technology is not commercial, but thorium represents a very large resource base.

Q: What you describe are large issues to be tackled by industry or governments. What about individuals? What can they do? We all do?

A: There’s a lot that individuals can do. Simply put, they fall under three categories: don’t waste, get informed, and get involved.

If we look around, each one of us is likely to find many opportunities in our lives for conserving energy. There’s no reason to waste energy, and we should turn off lights when no one is around. But I would urge people to focus on those opportunities that have large impact. Unplugging your cell phone charger is good; but the total amount of energy saved by that action is less than 3 kWh a year. Sure, if a billion such chargers were unplugged, we could avoid the electricity generated from a 400-MW coal-fired plant. So, while that’s not bad it’s not going solve the energy problem. And if we put all our psychic energy into fixing little things, we will not achieve our objective. We must focus attention on items than make a substantive difference. On a personal level, does it help us reduce about 20 GO/yr (or 240 kWh), which is about 1% of what we use in North America. The choices we make about food and vehicles can each save 200 GO/yr or more. Before you choose to install a solar panel for your home, make sure it is properly insulated and you have made other changes to reduce energy consumption.

That is where getting informed comes in. Please get educated about energy—how and how much of it is used and produced, as well as the ramifications of our energy choices for the environment, the economy, and social justice. There are risks associated with every action, including inaction. We have to learn about them. The CMO book is a start of that process.

Energy is a very important issue to let only the experts decide how we produce it. In many instances selection of developing one resource or another will be dictated by value judgments, and different people can and do value things differently. For that reason it is very important for us to let our leaders know what we value.

Q: An article in the New Yorker stated that there were no deaths attributable to the nuclear accident at Three Mile Island but 4000 at Chernobyl. is this true?

A. Yes, in one sense, but the statement requires explanation.

In the initial phases of the Chernobyl disaster the three occupants of the control room died within a few hours – if not minutes. The reactor containment structure required by US regulation and in many other countries around the world was not installed at Chernobyl or any Soviet state reactor. TMI radioisotope release was restricted to a very small quantity of radioactive gasses that quickly decayed the TMI damage to humans has been essentially undetectable. In fact many people in the general area surrounding the TMI plant are routinely exposed to radioactive gasses arising from the radioactive radon coming from the uranium and thorium contained in the rocks and soil around them than were exposed to the radiation from the accident that was only detected for a brief period.

In the case of Chernobyl, the accident took a more violent form and the reactor essentially exploded. As it was situated inside what was essentially a warehouse style building much of its contents were rapidly released to the atmosphere and almost all of the remaining material followed as the graphite – used for neutron moderation – burned. The blast itself and the burning graphite carried the radioactive fission products across the countryside but were first concentrated at the rector site and thus exposed the “first responders” to excessive levels of radiation and 37 died within days or months. To this we can add perhaps 13 more mainly of persons involved in cleanup activities. The 4000 number is an estimate of the number of people whose lives have – or will be shortened because of radiation-induced cancer to the general population by the cloud of radioactive materials the passed over or was deposited on the ground following the explosion. These deaths will be spread over time among a population of perhaps 5 million. Since cancer strikes about 20% of the population a million of the 5 million people are like to contract cancer; the additional 4000 cases from radiation would amount to an increase from 20% to 20.1%

Recent Comments

There are currently no comments.