L2. Our Resources, Our Consumption
Introduction
In order to fully understand the importance of biorenewable resources, we must first understand the predicament the world is facing regarding resource consumption. The following challenges are discussed in the first three lessons of this course:
- The “stuff” we consume either is extracted from the ground (e.g. petroleum, iron, copper, coal) or harvested (e.g wood, food, cotton).
- The U.S. and developed countries consume lots of “stuff”. Our consumption of resources is increasing as are the consumption habits of the rest of the world. This is a function of both population growth and the desire for an increased standard of living.
- There are negative environmental impacts to this extraction or non-renewable resources (or the planting and harvesting of renewable resources).
- Nations that are importing natural resources are transferring the negative environmental impacts of this consumption to other countries.
Read Irresponsible Pursuit of Paradise Chapter 2 (pgs 19-27 and 32-33). Some of the lesson content also came from Chapter 6 - you are welcome to read that chapter also :)
Everything in the video lectures are also found in the assigned book reading or in the lesson text below. Hence there is need for a pdf of the lecture.
Population and Consumption
As you recall, a resource is considered renewable if it is replenished faster than it is used. If this rate of consumption can continue indefinitely into the future, then the resources is being used sustainably. So what affects the rate at which we consume the Earth’s resources? Two things: 1) the number of people on the planet and 2) the amount of resources each of these people consumes.
Let’s do a quick exercise. Pull up a stopwatch on your phone/computer, and count as fast as you can for 30 seconds. Ready? Go.
Did you make it to 125? If not, you were counting slower than the rate at which the human population is growing. On average, about 4.3 babies are born every second of every single day, resulting in over 250 births per minute, and over 130 million births per year. When this birth rate exceeds the death rate then the population increases (like it is today). How much the population changes over time is called the growth rate Links to an external site..
The world population in 1800 was around 1 billion; today, that number is just under 7.5 billion (population clock) Links to an external site.. This equates to a 600% increase over 200 years. It should be noted that the population growth rate has been declining for at least 50 years. This means that although the world population is still increasing, it's not growing as fast as it used to (Figure 1).
Figure 1. World Population Growth and Growth Rate. (Our World in Data, World Population
Links to an external site.)
Consumption and Economic Growth
Estimates from the UN International Resource Panel Links to an external site. indicate that globally we are using about 90 billion tons (about 12 tons per capita) of material resources per year, but this is an average for the entire global population. THis number is valid but does not really tell the true story as some people consume very little and others consume alot. Per capita consumption in wealthy countries (like the U.S.) is 10 times greater than in developing countries.
In 2010, developed countries made up only 11% of the world's population, but consumed over 50% of the world's industrial wood and nickel, and over 40% of the world's lead, copper, and aluminum (Figure 2). These countries clearly consumed more than their "fair share".
Figure 2. Percent of Consumption by Developing World for various materials. (IPP)
It is rather difficult to grasp amount of consumption when dealing in terms of millions or billions of tons. How much is that really? More meaningful is the amount used per person (per capita). This is the amount of materials used divided by the number of people - shown in the last column of Table 1.
For example, the per capita use per year of cement in the U.S. is about 290 kg (640 lbs). That's a lot of cement! Cement, a main ingredient in concrete, is used for making roads, bridges, and buildings. Concrete is only about 8-15% cement, the other 85-92% is sand and rock. This means that in addition to all of that cement, we are using about 6,000 lbs of sand and rock per capita each year. The Mineral Education Coalition calculated that each American born today will consume about 3 million lbs of minerals, metals and fossil fuels in their lifetime (about 26,000 lbs per year). Note this consumption does not include any food, wood, paper, or water!!
Some of you may be thinking "I did not use any cement this past year - or steel. And there is no way I threw 100 lbs of stuff in my trash can last year". (IPP Chapter 7 estimates people in the US consume 38,524 lbs of minerals, metals and fossil fuels per year). You are right! The way these numbers are calculated is the amount of the resource used in the whole United States divided by the number of people. Resources used for building roads or bridges or football stadiums all count against you but you have no real control over this consumption. This is viewed as Indirect use of resources. If you burn a gallon of gasoline in your car or purchase a fan or tea kettle plastic, or use electricity in your home - that is Direct resource use. You have control over direct resource use. You can't do much about the larger, indirect resource use.
Table 1. Annual consumption of select Raw Materials (IPP, 2017. pg 97)
|
Global (Million metric tons) |
U.S. (Million metric tons) |
% used by U.S.* |
U.S. per capita kg (lbs) |
|
|
Cement |
4,180 |
93 |
2.2% |
290 (640) |
|
Steel |
1,670 |
110 |
6.5% |
340 (750) |
|
Aluminum |
54 |
5.4 |
10% |
17 (37) |
|
Plastics |
311 |
50.9 |
16% |
160 (350) |
|
Roundwood* |
1,656 |
189 |
11% |
590 (1300) |
*Wood used for both building and for energy. **Note also that the U.S. is only about 5% of the world population.
We have long seen these high rates of consumption in the world’s wealthiest nations. The change that is occurring today is a steep increase in consumption in developing countries. Economic development of a country is measured by Gross Domestic Product Links to an external site. (GDP). GDP is the economic value of all the goods and services produced over a given time period. GDP correlates well with the consumption of materials, because more money means people can buy more things. With economic development (increasing GDP) comes new roads, buildings, and vehicles, which means an increase in the consumption of cement, metals (steel and aluminum), plastic, and wood.
This short video by Hans Rosling demonstrates this concept with the purchasing of a washing machine. (Here is a direct link Links to an external site. to the TedX talk)
Hans has a great way of visualizing this trend in consumption. There are some real benefits of having things like washing machines!
This trend of more consumption with economic development is clear if we compare the increases in raw materials to the increase in population over the time period 1960-2014 (Table 2). During this period the population more than doubled (2.3 times). If consumption increased only with population growth, then the consumption of materials would have also increased 2.3X. However, consumption of all materials, except wood, increased 4 to 50 times. The use of wood per per person actually decreased during this time period! This is important to remember.
Table 2. Growth in Consumption of World Raw Materials 1960-2014 (Population growth during this period = 2.3X)
|
Steel |
Cement |
Aluminum |
Plastics |
Wood |
|
4.75X |
11.9X |
11.9X |
51.8X |
1.8X |
Figure 3 shows how dramatically consumption of raw materials has increased over the last century. Also note how closely consumption is linked to economic growth in the U.S. Any slowdown in the economy (e.g. recession) causes a slowing of resource consumption. The 'problem' is that we want economies to grow as that growth helps people achieve a higher standard of living. Yet this growth means natural resource consumption. But is this a bad thing?
Figure 3. US Non-Fuel Materials Consumption. (New Mexico Mineral Resources Links to an external site..)
As economically developing countries become increasingly developed, per capita consumption of food and raw materials increases. It is increasing faster than ever before. When combined with an increasing global population, the effect is an explosion in consumption. We learned in Lesson 1 that resources like cement, and metals are non-renewable, meaning they don't renew themselves fast enough to be used sustainably. So if consumption is exploding but our resources aren't regenerating... does that mean we will soon be running out of resources?
Are we running out of non-renewable resources?
(Photo is the worlds largest copper mine. Escondida, Chile. Just for fun, here (Links to an external site.) are some great images of the 10 largest copper mines in the world.)
Often we think of our use of non-renewable resources like this: I have 12 eggs and I eat two eggs per day. I could then calculate that in 6 days I will “run out” of eggs. A finite supply of eggs and a fixed rate of use allows us to calculate the time before the supply is depleted.
However, with our non-renewable natural resources the situation is more complex. Figure 4 is a typical way to represent non-renewable resource supplies. Let’s say this figure represents coal, but it could be petroleum, iron, coal, copper, etc. The large triangle represents the estimate of how much of coal there is is on earth. The top small triangle of the pyramid represents the amount of coal that is economically recoverable (often noted as “proven reserves”). Proven reserves are a function of market prices and cost of extraction. Proven reserves are typically a very small fraction of the total reserves.
Example: Imagine a geographic area that has large deposit of coal. The first area of coal is on the surface of the earth. It can be mined profitably for $1 per ton. The second area of coal is deeper in the ground and can only be accessed by removing a significant amount of earth that lies on top of the coal. This coal can be extracted profitably for $10 per ton. The third area of coal can only be access by tunnels going deep into the ground. Extracting coal from this area is profitable at $100 per ton. So if this is all the coal available, what are the proven reserves?
If the market price for coal is $1/ton, then the proven reserves would be the amount of coal in the first area. If, however, the market price for coal is $10/ton, then the first and second area would be included in the proven reserves. Let's say there's a new development in technology, and coal can now be extracted from the third area for $10/ton; in this case, areas 1, 2, and 3 would be included in proven reserves. Have the total reserves of coal changed? No. Have the proven reserves changed? Yes.
This same kind of pyramid could be made for any mineral or fossil fuel. The total reserves are typically very large and the proven reserves sometimes called “recoverable resources” are a function of the cost to extract the material and the price paid for the material.
Currently the global proven reserves for coal are 1.1 trillion tons. We are using coal at a rate of about 9 billion tons per year which means we have around 120 years of coal before we run out. (World Coal Association). However, as we discussed, proven reserves is a function of economics. Will we run out of coal in 120 years? Not likely. Will it get more expensive to extract coal? Probably.
So when we ask the question “when will we run out” of resource X or Y, the answer is much more complicated than the egg example we started with. As we described, “When will we run out?” is a function of how much is being paid for the material, how fast we are using the material, and how economical is it is to extract the material.
Reserves to Production Ratio
The “Reserves to Production Ratio” (R/P Ratio), also known as the Reserves Life Index, relates to the question "how long before we run out". This is the ratio of proven reserves (R) to how fast we are producing it (P). (For our egg example, the R/P Ratio is 6 days.) This ratio is specific to the resource. The Ratio also changes depending on the many factors that were just discussed.
Figure 2 shows this R/P for petroleum over time. Note that in 1980 the R/P was about 27 years, meaning that by 2007 the supply would be depleted if nothing changed. However, in 2007 the R/P was estimated at 42 years. In 2017 the R/P for oil is 50.2 years (BP: Oil Reserves (Links to an external site.)).
Figure 2. R/PR for petroleum over time. (BP: Oil Reserves (Links to an external site.))
So are we running out of non-renewable resources soon? The simple answer is no! However, nothing is that simple and there is more to the story. "Will this relatively constant R/P continue if developing nations start consuming at the rate of developed countries?" or "What is the environmental impact of all this resource consumption and is that sustainable?" Or maybe the a good question is "Who owns or controls the resources?" We will be looking at some of these questions in the next lesson.
If you have not yet done so, read Chapter 2 of Irresponsible Pursuit of Paradise. Skip the part in italics if you want (pgs 28-31).