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Ecological footprint

Created Ecological footprint

I intend to expand this page, at least if I manage to find out how it's exactly being calculated.

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1.

If somebody would like to discuss the concept of ecological footprint, I have some questions which were raised while I was reading about it.

The ecological overshoot is due to the land necessary for carbon uptake. But this is assumed to be forest land. Now, suppose, that we would burn less carbon and that, in fact, one earth would suffice for our ecological footprint. In that case we could manage the earth's surface in such a manner that each land is used to support our consumption. I think that forests in equilibrium don't accumulate carbon dioxide, so there is the implicit assumption that this forest land for carbon uptake consists of growing trees, which (at some point) should be harvested and stored (say, on the ocean floor), and we assume for simplicity that this can be done without additional ecological costs. If the trees were not harvested, there wouldn't be enough land anymore for carbon uptake once the forest gets mature.

But even if we would use only "one earth", burning of fossil fuels will not become more sustainable. Due to the carbon uptake land it would seem that we live sustainable according to the ecological footprint, but fossil fuels will not be renewed in human lifetimes.

So I'm not really sure if the ecological footprint is a very useful concept. It's good concept to give the public a visual impression that we're not living sustainable now, but even if we use only one earth according to the ecological footprint, it doesn't imply we will be suddenly living sustainable. To get an idea what capacity of human footprint the earth can really bear, we could, for example, calculate how much timber we would have to burn to support our current economy (instead of fossil fuels) and then calculate how much forest land we would need to -sustainably- supply the necessary timber. I guess it will be much more than 1,5 earths...

Anyway, this concept is not very important, but if somebody would like to discuss it, I'll be glad to hear another opinion.

Comment Source:If somebody would like to discuss the concept of ecological footprint, I have some questions which were raised while I was reading about it. Please correct me when wrong. The ecological overshoot is due to the land necessary for carbon uptake. But this is assumed to be forest land. Now, suppose, that we would burn less carbon and that, in fact, one earth would suffice for our ecological footprint. In that case we could manage the earth's surface in such a manner that each land is used to support our consumption. I think that forests in equilibrium don't accumulate carbon dioxide, so there is the implicit assumption that this forest land for carbon uptake consists of growing trees, which (at some point) should be harvested and stored (say, on the ocean floor), and we assume for simplicity that this can be done without additional ecological costs. If the trees were not harvested, there wouldn't be enough land anymore for carbon uptake once the forest gets mature. But even if we would use only "one earth", burning of fossil fuels will not become more sustainable. Due to the carbon uptake land it would seem that we live sustainable according to the ecological footprint, but fossil fuels will not be renewed in human lifetimes. So I'm not really sure if the ecological footprint is a very useful concept. It's good concept to give the public a visual impression that we're not living sustainable now, but even if we use only one earth according to the ecological footprint, it doesn't imply we will be suddenly living sustainable. To get an idea what capacity of human footprint the earth can really bear, we could, for example, calculate how much timber we would have to burn to support our current economy (instead of fossil fuels) and then calculate how much forest land we would need to -sustainably- supply the necessary timber. I guess it will be much more than 1,5 earths... Anyway, this concept is not very important, but if somebody would like to discuss it, I'll be glad to hear another opinion.
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2.
edited December 2010

I don't entirely understand the point you're making above. As a first point, my understanding is that ecological footprint takes the view that $CO_2$ emission isn't the only problem, eg, limits on drinkable water per person.

You seem to be saying that "global lifestyle" which has an ecological footprint of "1 earth" which uses

1. fossil fuels isn't sustainable because they'll run out.

2. burns other things has a much, much larger ecological footprint than 1 earth.

These are very probably accurate statements. I guess the question is: supposing things like solar-power and nuclear get installed amazingly fast, is it possible to have a global lifestyle which is "energy/$CO_2$ sustainable" but isn't "ecologically sustainable" (due to, eg, water shortage)? Or is it the case that the "ecological footprint" measure is redundant due to energy sustainability being strict enough?

Is that what you're saying?

Comment Source:I don't entirely understand the point you're making above. As a first point, my understanding is that ecological footprint takes the view that $CO_2$ emission isn't the only problem, eg, limits on drinkable water per person. You seem to be saying that "global lifestyle" which has an ecological footprint of "1 earth" which uses 1. fossil fuels isn't sustainable because they'll run out. 2. burns other things has a much, much larger ecological footprint than 1 earth. These are very probably accurate statements. I guess the question is: supposing things like solar-power and nuclear get installed amazingly fast, is it possible to have a global lifestyle which is "energy/$CO_2$ sustainable" but isn't "ecologically sustainable" (due to, eg, water shortage)? Or is it the case that the "ecological footprint" measure is redundant due to energy sustainability being strict enough? Is that what you're saying?
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3.

fderoo said

there is the implicit assumption that this forest land for carbon uptake consists of growing trees

I think this is an explicit assumption in Wackernagel et al, 2002:

Burning fossil fuel adds CO2 to the atmosphere. We calculate the area requirement by estimating the biologically productive area needed to sequester enough carbon emissions to avoid an increase in atmospheric CO2. Because the world's oceans absorb about 35% of the CO2 emissions from fossil fuel combustion (27, 28), we account only for the remaining 65%, based on each year's capacity of world-average forests to sequester carbon. This capacity is estimated by taking a weighted average across 26 forest biomes as reported by the IPCC and the FAO (18, 28–30). The sequestration capacity will not remain constant in the future. For instance, changed atmospheric CO2 concentrations and global temperature may increase the eventual saturation biomass level and the rate at which that is approached. Some sequestration and oceanic absorption may even be reversed. Also, CO2 sequestration rates may decrease as more and more forest ecosystems reach maturity. Eventually afforestation will saturate so that the net rate of CO2 uptake goes to zero.

My emphasis. I get the impression they are mainly interested in short term (say decades to a century) sustainability.

Comment Source:fderoo said > there is the implicit assumption that this forest land for carbon uptake consists of growing trees I think this is an explicit assumption in Wackernagel et al, 2002: > Burning fossil fuel adds CO2 to the atmosphere. We calculate the area requirement by estimating the biologically productive area needed to sequester enough carbon emissions to avoid an increase in atmospheric CO2. Because the world's oceans absorb about 35% of the CO2 emissions from fossil fuel combustion (27, 28), we account only for the remaining 65%, based on each year's capacity of world-average forests to sequester carbon. This capacity is estimated by taking a weighted average across 26 forest biomes as reported by the IPCC and the FAO (18, 28–30). The sequestration capacity will not remain constant in the future. For instance, changed atmospheric CO2 concentrations and global temperature may increase the eventual saturation biomass level and the rate at which that is approached. Some sequestration and oceanic absorption may even be reversed. Also, CO2 sequestration rates may decrease as more and more forest ecosystems reach maturity. <b>Eventually afforestation will saturate so that the net rate of CO2 uptake goes to zero.</b> My emphasis. I get the impression they are mainly interested in short term (say decades to a century) sustainability.
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4.

@ Graham: thanks!! I had only read the beginning of the Wackernagel, 2002 paper (to check a reference) and my mentioning of "implicit assumption" pointed to another source. Anyway, I'm glad it has already been considered somewhere. I'll add it to the wiki.

@ David:

but isn't "ecologically sustainable" (due to, eg, water shortage)

I hadn't been thinking of this, but you're right that, in a truly sustainable society, it's another aspect that should be considered.

My main point was that I think that the concept of "ecological sustainability" is not well defined. But as Graham suggests:

I get the impression they are mainly interested in short term (say decades to a century) sustainability.

So I'll just add this to the wiki, that "ecological footprint" refers to a "short term" sustainability (unless someone else on the Forum has another opinion). So for long term sustainability another concept should be calculated.

Comment Source:@ Graham: thanks!! I had only read the beginning of the Wackernagel, 2002 paper (to check a reference) and my mentioning of "implicit assumption" pointed to another source. Anyway, I'm glad it has already been considered somewhere. I'll add it to the wiki. @ David: > but isn't "ecologically sustainable" (due to, eg, water shortage) I hadn't been thinking of this, but you're right that, in a truly sustainable society, it's another aspect that should be considered. My main point was that I think that the concept of "ecological sustainability" is not well defined. But as Graham suggests: > I get the impression they are mainly interested in short term (say decades to a century) sustainability. So I'll just add this to the wiki, that "ecological footprint" refers to a "short term" sustainability (unless someone else on the Forum has another opinion). So for long term sustainability another concept should be calculated.
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5.

An article titled Does the Shoe Fit? Real versus Imagined Ecological Footprints argues that

EF measurements, as currently constructed and presented, are so misleading as to preclude their use in any serious science or policy context.

I've added this ref to the page.

Comment Source:An article titled [Does the Shoe Fit? Real versus Imagined Ecological Footprints](http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001700) argues that > EF measurements, as currently constructed and presented, are so misleading as to preclude their use in any serious science or policy context. I've added this ref to the page.
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6.
Ecological footprint is about limiting factors, so clean water, energy, food, etc... And all of the components of these. The difficult part is that we have a huge n-dimensional version of guns and butter, except with a limiting set of factors instead of something that optimizes production. These limiting factors are constantly changing as availability and human behavior changes. Since human behavior can vary substantially, models can be extremely inaccurate when people make unrealistic assumptions about human behavior, eg the Simon–Ehrlich wager and the World3 model.
Comment Source:Ecological footprint is about limiting factors, so clean water, energy, food, etc... And all of the components of these. The difficult part is that we have a huge n-dimensional version of guns and butter, except with a limiting set of factors instead of something that optimizes production. These limiting factors are constantly changing as availability and human behavior changes. Since human behavior can vary substantially, models can be extremely inaccurate when people make unrealistic assumptions about human behavior, eg the Simon–Ehrlich wager and the World3 model.