Does the Earth Have an Optimal Distribution of Fossil Fuels?

When speaking about global warming, people sometimes talk about fossil fuel reserves as a kind of great threat to us that we must resist fully using, or else face ruinous consequences. Some say that we have what is called a carbon budget that we must stick to, to avoid a future temperature rise greater than 2 degrees Celsius. The carbon budget has been described as being no more than 1500 gigatons of carbon dioxide that can be expended before the year 2050. Presumably a higher budget would be allowed for the period up until 2075 and the period up until 2100. It is argued that we must use great restraint in limiting ourselves to this carbon budget, rather like some person who can take some morphine pills, but who must restrain himself from taking too many, lest he die from an overdose.

But there is actually a reason for believing the chance of a carbon dioxide “lethal overdose” is low, and perhaps nonexistent. The reason has to do with the extent and nature of fossil fuel reserves. For one thing, there are not unlimited amounts of coal, oil, and natural gas lying about. The oil reserves of the top 15 oil producers is only about 1540 billion barrels, which is about 50 years of current global oil use, and considerably smaller than that if we allow for future population growth and economic growth. Some are worried that we may soon hit the “Peak Oil” point that has long been predicted. Although it is claimed that coal reserves are sufficient to last for 153 years of global production, many think that we will hit “Peak Coal” within a few decades.

What is called a resource pyramid is one of the reasons why both coal and oil production may decline within a few decades. As shown below, the resource pyramid is the concept that the easiest coal and oil resources to extract are found in the smallest amounts. The resources that are found in the greatest amounts are those which are hardest to extract.

 A resource pyramid

 

Because coal and oil resources are arranged in a kind of resource pyramid, with most of the resources being very hard to extract, it is quite possible that there is almost no chance that mankind will “overdose” on carbon resources. By around the middle of the century, we may find it harder and harder to extract coal and oil resources, as we work our way deep down the resource pyramid of oil and the resource pyramid of coal. The very distribution of these resources may put a brake on runaway consumption, forcing humanity to reduce consumption and switch more to alternate energy sources such as solar and wind.

David Rutledge of Cal Tech has predicted that by 2069 the world will have produced 90% of the coal that it will ever produce. If something like that happens, the worst projections of the IPCC will not occur, and the world's temperature will probably never rise much higher than 2 degrees Centigrade above its current level.

These facts bring to mind a very interesting question that has rarely been considered: what would be the optimal distribution of fossil fuels that our planet might have had? And also: is it possible that the earth's actual distribution of fossil fuels is something close to an optimal distribution?

First, let us consider some distributions of fossil fuels that would not have been optimal. One distribution we can imagine is one in which our planet simply had no fossil fuels at all: no coal, no oil, and no natural gas. In such a case there would have been no modern civilization of the type we have enjoyed for the past 100 years or so. That obviously would not have been an optimal distribution of fossil fuels.

Another distribution of fossil fuels we can imagine is one in which oil and coal started to run out at a time such as about 1980. That also would not have been an optimal distribution of fossil fuels.

We can also imagine a distribution of fossil fuels in which coal and oil resources were two or three times higher than our planet has, with two or three times more easily accessible resources. In that case there might have been a much higher chance of catastrophic global warming caused by excessive use of fossil fuel resources.

Instead of any of these possibilities, what we may have on our planet is pretty much an optimal distribution of fossil fuels. The fossil fuels we have are enough to last us until the cost of alternate energy sources such as solar power and wind power falls down so low that such things (possibly assisted by nuclear fusion) can serve as replacements for fossil fuels. But existing as they are in a resource pyramid, the fossil fuels we have may be distributed in such a way so that the easily accessible resources start to gradually run out just at about the time that we will need for them to run out, so that we don't overheat the planet by burning too much carbon. At just about the best time for such a message, nature will in effect start telling us, “It's time to switch away from fossil fuels -- I'm going to slowly make it harder and harder for you to get them.” And nature will start delivering that message in a louder and louder voice over the span of several decades. We will get this message from nature pretty much at just the right time -- all because fossil fuels just happened to be distributed in a particular way that may turn out to be very lucky for us. 

If we have such a nearly optimal distribution of fossil fuels, we may wonder whether that is an improbable lucky coincidence, or something that was set up in advance for our benefit.

Doubts About Today's Global Temperature Rise Headline

There was a sensational headline in the news today. The Guardian headline said Planet likely to warm by 4C by 2100, scientists warn. If that is true, it's some of the worst news imaginable. The link here describes the horrors of a world in which temperature has risen by 4 degrees Centigrade. The acidity of ocean waters would increase by 150%. Many nations would be plagued by heat waves. Water shortages would be greatly increased. The number of devastating forest fires would greatly increase. Many coastal cities would be flooded. The agricultural system might take a major hit.

But is it really likely that global temperatures will increase by at least 4 degrees Centigrade by 2100? It seems not. There are still reasons for thinking that the chance of such a rise in temperature is less than 50%.

The alarming headline was a result of a study on what is called climate sensitivity. Climate sensitivity is the issue of how much global warming will be produced by a particular amount of increase in the carbon dioxide in the atmosphere. Scientists debate how much the temperature will rise if the carbon dioxide in the atmosphere doubles from its current level of 400 parts per million, to become as high as 800 parts per million. A post on RealClimate.org says, “The ‘meta-uncertainty’ across the methods remains stubbornly high, with support for both relatively low numbers around 2ºC and higher ones around 4ºC, so that is likely to remain the consensus range.”

The study announced today was taking a position that doubling the atmosphere's carbon dioxide will cause an increase of 4ºC, but other scientists apparently think that the climate sensitivity is only half as much, and if they are right, doubling carbon dioxide will produce a temperature rise of only 2ºC.

Another reason for doubting today's shocker headline is that it is very much uncertain whether carbon dioxide levels will double by the end of the century. It seems as likely as not that they will only rise by a much smaller amount, an increase such as 50%.

Here is an IPCC graph showing projected rises in carbon dioxide under different IPCC scenarios for global warming:

IPCC Projections of Carbon Dioxide Increases

Note that in most of these scenarios, the carbon dioxide only increases to 600 parts per million or less by the year 2100. But today's shocker headline is based on both a worst-case climate sensitivity assumption, and also a very pessimistic projection of carbon dioxide increase (one projecting a doubling of carbon dioxide to 800 parts per million by 2100).

I may note there are fossil fuel resource availability experts (such as Dave Rutledge of Cal Tech) who think that carbon dioxide will not be able to increase to much beyond 500 parts per million by the end of the century, simply because global demand for coal and oil will exceed the supply in a few decades. In this link Rutledge cites a Schmitz model which projects a peak in carbon dioxide levels at 459 parts per million in the year 2067, at a point when 90% of fossil fuels will be exhausted.

So let's do a little probability analysis here. Let's assume that there's a 50% chance that the “climate sensitivity” pessimists are right, and that a doubling of carbon dioxide would produce a 4 degrees centigrade increase in temperature. Let's also assume that there's a 50% chance that experts such as Rutledge are right, and that we won't get anything close to a doubling of carbon dioxide by 2100 (as well as a 50% chance that carbon dioxide levels will double by 2100). That means the chance that we will actually see a 4 degrees centigrade temperature rise by 2100 is roughly 50% times 50%, or roughly 1 in 4.

This is why it is dubious journalism indeed for news sources to be showing headlines like today's headline Planet likely to warm by 4C, scientists warn. A more accurate headline might be 25% Chance of Temperatures Rising by 4 Degrees Centigrade by 2100, but of course, such a headline wouldn't generate as many web clicks.

Does this mean we can be complacent and continue with our wicked ways of profligate conspicuous consumption? Not at all. A 25% risk of a 4C global catastrophe is still reason enough for reducing your carbon footprint. Moreover, the very considerations I have cited about resource exhaustion provide an additional impetus for conserving resources, perhaps one even more powerful than the global warming rationale. If 90% of the world's fossil fuel resources will be exhausted by the year 2067, we have a moral duty to conserve those resources, to minimize the chance of a devastating Energy Crunch later in this century that may leave many millions starving, shivering, or sweating out their lives, while sometimes fondly remembering the days when there used to be regular electrical power.

Imagine a father driving his car on a cross-country trip, and inside the car are his wife and his daughter. The father drives through long empty roads of Nevada at excessive 80 mile an hour speeds. The wife warns the husband, “Don't drive so fast – the engine will overheat and the car will catch on fire.” But the daughter has a different warning: “Don't drive so fast – we must conserve gas or we'll run out in the middle of the desert.” The father represents our culture of runaway consumption. The mother represents the warning of climate experts. The daughter represents the warning of resource reserves experts, who give us an entirely different, but perhaps even more compelling, reason for reducing our runaway consumption.

The Coming Energy Crisis

The decades ahead will probably see an energy crisis so great that it dwarfs the financial crisis that began in 2008.

The reason for the crisis is that global energy demands are increasing, caused by population growth and increased consumption in countries such as India and China; but our production of fossil fuels will not increase enough to keep up with this need. In fact, the global production of oil may soon begin to fall, and the global production of coal may start to decline between one and four decades in the future.

Global oil production rose steadily between 1985 (when it was 60 million barrels a day) to 2005 (when it was about 85 million barrels a day). Since then there has been hardly any increase. Many experts predict that global oil production will soon begin to decline. The thesis that the global demand for oil will soon exceed the supply is the Peak Oil thesis. We know that in quite a few countries, oil production has peaked. For example, the oil production of the United States peaked in the early 1970's, and has declined sharply since then. 

In a country such as Saudi Arabia, 60% of the oil comes from a giant field called the Ghawar field. But the Saudis have resorted to injecting huge amounts of sea water into the field (supposedly millions of gallons a day) to keep it producing at a high rate. If the field follows the typical production history for oil fields (that of a bell-shaped curve), the field's production will soon begin to steadily decline, as will many other oil fields.

But what about coal? The standard forecast for coal (repeated innumerable times) has been that we have hundreds of years of coal. But quite a few recent estimates have challenged this rosy prediction.  A group called the Energy Watch Group predicted in 2007 that global coal production could peak by the year 2022. Dave Rutledge of the California Institute of Technology estimates that by the year 2070 we will have used up 90% of the coal that will be burnt.

If such an estimate is correct, it would presumably be good for the environment, because it would mean that the gloomier predictions of the IPCC regarding global warming would probably not occur. Such predictions are based on the assumption that man's production of fossil fuel will grow unabated.

But if we see both a peak in oil production and a peak in coal production before the middle of this century, there will be a gigantic energy crisis that may include economic depression and possibly even mass starvation. With a growing population and growing consumption, we will need for energy supplies to keep rising steadily, but exactly the opposite may be in store. The shortfall may lead to a crisis which may in the short term be even worse than the global warming crisis. 

What about renewable energy? Won't that make up for the shortfall? Today the World Bank issued a report noting that despite the fact that wind power has grown at a rate of 25% per year since 1990, and solar power has grown at a rate of 11 percent since 1990, renewable energy overall is only growing at a very small rate. Renewable energy (most of which is hydroelectric energy) only makes up about 18% of our energy, and that percentage has hardly increased since 1990. If current growth rates continue, we'll only have a fraction of the renewable energy we need when our production of fossil fuels starts to sputter. 

Here is a graph from the report:

 

Some optimists imagine that nuclear power may fill the gap, but things don't look very promising on that front. Scientists have been working for fifty years or more to create nuclear fusion (a clean form of nuclear energy), but we are still nowhere close to having a working nuclear fusion reactor. As for fission reactors, their cause suffered a great setback when the Fukushima reactor in Japan suffered a catastrophic malfunction.

We can't wait until the next energy crisis explodes in our face. We have to put the needed renewable energy units in place years before we need them. China is making heroic strides in this area, but the West (including America) lags behind.

What can the average person do? Reduce your energy use and slash your carbon footprint. When you jump in a jet liner to go from New York City to see mountains in some exotic country (when you could have enjoyed mountains in your same state), or when you live in a house of 2500 square feet (when 1000 would have done fine), you are helping to use up our dwindling reserves of fossil fuels. The end result in the future may be a family shivering in a cold house or a family going hungry.