Wednesday, August 23, 2006

Can the Earth Handle all Humans Consuming at American Levels?

With the average levels of American consumption rivaling Egyptian pharaohs, the question of whether we are over consuming arises. Is our consumption sustainable, or will we ultimately need to cut back? Are we using more than our fair share of the Earth's resources? This all leads to one basic question: can the Earth support all humans consuming like Americans?

Lets break this question into two parts. First, can the Earth support everyone on the planet consuming like Americans today? Second, can the Earth in 2050 support everyone consuming like Americans with 2050 technology?

To answer the first question, lets once again refer to the WWF's Living Planet Report. On page 28, they break down the ecological footprint of the US. Per capita, Americans have a 9.5 hectare footprint, made up of 3.0 hectares in food and fiber (0.96 cropland, 1.35 forest, 0.44 grazing land, 0.23 oceans), 6 hectares in energy and .45 hectares in built up land.

If you take the 9.5 hectares and divide it by what they consider the world per capita sustainable amount of 1.8 hectares, you get a value of 5.3 Earths required for everyone to live at American standards. Likewise, if you measure your own footprint using this Ecological Footprint Quiz, you will likely get a value around 5 Earths required to support your consumption.

Would it really require 5.3 Earths worth of land and resources for everyone to consume at the level of the US?

I don't think so. First, as I wrote about before, I don't think energy belongs in the calculation. Removing the 6 hectares of energy, the footprint goes down to 3.5 which means we need 2 (well really 1.94) Earths. Energy is a separate issue which I will come back to in a moment.

Brief Aside: Could the US sustain its consumption if isolated from the rest of the world?

The US has 4.9 hectares of biocapacity (p 29) so, excluding energy, we are only using 71% of our total capacity. This explains how the US has been able to reduce the amount of farm land and increase the amount of forests which wouldn't be possible if we were living beyond the biocapacity of our land. On the energy side, there isn't enough oil for the US to use, but there is enough coal to maintain our energy usage if we could convert coal into gasoline.

I think even the 2 Earths number is an overstatement based on a methodology issue I have with the report.

Not all land is equally productive. The amount of sunlight and temperature varies due to latitude. The quality of the soil and the amount of rainfall also varies due to location. A given piece of land also varies in productivity based on farming practices, amount of fertilizer use, pesticide use and crop genetics. To make things equal for reporting, the researchers figured out what the average productivity was for a given hectare of land and adjusted the weight of the land accordingly (more details on page 36 and 37 of the report).

While I understand the need to do this, it leads to some strange conclusions. For example, New Zealand's forests are 2.4 times as productive as the world average. One hectare of forest land in New Zealand is therefore counted as 2.4 global hectares of biocapacity. Meanwhile, Algeria's forests are .1 times as productive as average. 10 hectares of forest land in Algeria are counted as 1 global hectares of biocapacity. What this means is that all efficiency gains that countries have created due to smarter farming or harvesting techniques are lost when calculating the countries footprint. Based on how the footprint is calculated, an Algerian that uses 10 hectares of land to produce 5 tons of lumber has the same footprint as a New Zealander that uses .41 hectares.

If a New Zealander comes up with a technique to double the productivity of his land and chooses to increase his consumption by 10%, he now has a surplus that he can sell. I would think this would mean he has decreased his footprint because he no longer needs as much land to produce the same amount of goods. But, due to the way the ecological footprint is calculated, this would show him actually having a larger footprint, as his consumption has increased by 10%, but the efficiency gains he created don't stay with him but rather are averaged around the world in the global hectares of biocapacity number.

Paradoxically, if farmers in Africa get smaller crop yields per hectare of food due to over population and bad farming techniques (see Jared Diamond's chapter on Rwanda in Collapse), this actually increases the footprint of the average American. Even though America didn't change anything, because African yields are smaller the average world yield per hectare is smaller and this makes the American consumption in terms of global hectares of biocapacity go up. And because these values are all based on averages per capita, as the world population increases, the land per capita goes down. So high birth rates in the 3rd world also make America's per capita percentage of the Earth's resources go up, even if nothing changed in America.

The countries that have the largest food, fiber and timber footprint are Finland, Sweden, New Zealand, and Norway (see page 12). This could either be because they eat tons of food and cut down trees like crazy, or because their land is so much more productive than average that their consumption looks a lot larger than it really is. Considering that those countries are usually listed among the more ecologically responsible nations on the Earth, I would guess the later.

If it were up to me, I would allow countries that have productivity gains to be reflected as a smaller footprint. What would happen to America's footprint if we allow our productivity to be included in the calculation?

According to the FAO, the US has a yield of 10 tonnes/ha of corn vs. a world average of 5 or excluding the US 3.6. So the US gets almost 3 times as much corn from each acre of land as the rest of the world does. While this is the most important crop it terms of total tonnage, wheat and soybean yields in the US are just at world averages (this is surprising to me). Overall, I would guess then that the US is much more productive per acre of land than the rest of the world, but I would guess it doesn't quite reach the 2 times level that would be required to say that we are living within our fair share of the world's biocapacity (fit our 3.5 hectare footprint into the 1.8 hectares of sustainable capacity). Another way of putting this is if all of the world's agricultural land was as productive as America's, I think the world would be very close to being able to eat like Americans.

Can the world consume energy like America? No. The US consumes 25% of the world's oil with only 5% of the world population. For the entire world to consume oil like Americans we would need 5 times as much oil or 400 million barrels of oil a day which I don't think is possible. Likewise there is not enough natural gas or coal to allow everyone to consume like Americans.

To answer the first question, using the average world land productivity, the Earth could not support everyone to consume like Americans (we would probabaly need 2 Earths). If the entire world had the same productivity as the US, I think everyone could almost consume like Americans. And there are not enough fossil fuels available for everyone to use energy like Americans.

Now on to the second question: can the Earth sustain an American level of consumption in 2050 with 2050 technology?

First, lets assume that in 2050 there will be 10 billion people on the planet (this is slightly more than the UN's estimate of 9 billion). Some estimates put 10 billion at the number where human population will ultimately peak.

Second, what kind of improvements do we need to see with agriculture to allow all humans to eat like Americans? The increase in population from 6.1 billion to 10 billion would mean that the sustainable level of 1.8 hectares would go down to 1.1 hectares. To allow everyone to be at the level of Americans we would need to make that 1.1 hectares 220% more productive to get to the 3.5 hectares an average American uses. Is that kind of improvement possible?

Lets look at what the level of improvement that has already occurred.

From Against the Grain:

In just 11 year period 1975-86, rice yields jumped 32% worldwide, wheat yields by 51%.
US corn yields stood at about 20 bushels/acre in 1900, as they had through most of history, at century's close 130.
From the Skeptical Environmentalist:
World yield of wheat went from 1.0 tons/ha in 1940 to 3.0 in 2000
World yield of rice went from 1.5 in 1880 to approximately 4.5 in 2000
Yield of rice, corn and wheat in developing countries has gone from about 1 ton per ha in 1960 to 2.5 in 2000
In Andhra Pradesh, India, research stations regularly attain yields 5 to 10 times the yields experienced by traditional peasants.
As these examples show, we have been able to triple productivity in the past, and I believe we can see another tripling in the future. I don't know if the same would be possible with timber but I would guess that it would be. And most wood products can be replaced with other products like ebooks for paper and concrete or bamboo for building materials. With fishing I would not think we will see such gains, although if we do some unconventional things like fertilize the open oceans, maybe.

Third, on the energy front we need to transition to sustainable sources of energy. There is solar and wind to allow everyone to consume energy at the level of Americans. The economics will dictate how long this transition takes. By 2050, I think renewable energies will be cost competitive with fossil fuels. I am hopeful new battery technologies or fuel cells will allow our cars to use solar or wind electricity as a power source so we will no longer need to use oil.

Long term, I think it is possible with better technology for all humans to be able to live at American levels of consumption in a sustainable fashion. In the short term this will not be possible, so Americans might need to cut back on their consumption to allow nature and 3rd world countries to have access to more resources.


Anonymous said...

Nice investigation, I relly like it...
Was looking through the whole internet for an article like this one. Nice job :)

Fat Knowledge said...


Glad it was helpful.

Anonymous said...

Very interesting article, though it does all seem to rest on your discounting of the energy hectares and then not offering a reason as to why they were counted in the first place and then to why you discount them. Would be interested to hear your thoughts.

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