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Step 8The ecological footprint
SUMMARY:
Here I make an estimate of the ecological footprint of use of the light fixture, and relate that to a person's share of Earth's productive capacity.
DETAIL:
This is where I get into very murky waters.
The basis for calculating an ecological footprint should be straightforward in principle, but the details quickly make it very difficult.
Let's work backwards to explain. The final calculation depends on an estimate of the Earth's yearly productive capacity, usually expressed in hectares.
On the web site for Redefining Progress, they calculate this productive capacity to be 10.8 billion hectares (land and water).
Since the human population numbers 6.6 billion people, each person's share of Earth's productive capacity is 1.6 hectares.
That was the easy part.
By current estimates, Canadians consume the equivalent of 7-8 hectares per person.
How is this possible?
1. The developing world consumes far less. For instance, the average Indian consumes the equivalent of 0.8 hectares.
2. A significant portion of Canadians' consumption is of non-renewable resources (fossil fuels, minerals) which, by definition, cannot be included as part of Earth's productive capacity.
3. The consumption, and volume of waste products output by Canadians' consumption, is actually overloading Earth's productive capacity. Witness the degradation of fresh water resources, depletion of fisheries, and rapid accumulation of greenhouse gases. By the way, Earth's processes for re-absorbing and converting those wastes is included as part of its productive capacity.
So, the ecological footprint of this light fixture can only be calculated by assuming that its manufacture, use, and disposal, consumes renewable resources.
Renewable energies can be used to power the light, which is actually its greatest impact.
The wood would come from sustainable forestry.
The metals must be reused or recycled, and renewable energies consumed to do so.
The PVC comes from our most valuable future resource: landfill. ;-)
Since the use phase so outweighs the production and disposal phases (and that I have no data to use), I have only calculated the footprint of the use phase.
Yearly consumption by the CFL bulbs is 62.4 kWh.
Yearly consumption by the incandescent bulbs is 249.7 kWh.
I used a spreadsheet available from Redefining Progress to calculate the footprint, and have attached it below.
Briefly, 62.4 kWh per year consumes .014 hectares. That equates to 1/115th of each person's 1.6 hectare share of Earth's productive capacity.
In contrast, 249.7 kWh per year consumes .055 hectares. That equates to 1/29th of each person's share of Earth's productive capacity.
(These share figures assume that there is only one person in the household.)
I must confess to being inspired by Bruce Sterling, and his book "Shaping Things", for attempting this project.
Here I make an estimate of the ecological footprint of use of the light fixture, and relate that to a person's share of Earth's productive capacity.
DETAIL:
This is where I get into very murky waters.
The basis for calculating an ecological footprint should be straightforward in principle, but the details quickly make it very difficult.
Let's work backwards to explain. The final calculation depends on an estimate of the Earth's yearly productive capacity, usually expressed in hectares.
On the web site for Redefining Progress, they calculate this productive capacity to be 10.8 billion hectares (land and water).
Since the human population numbers 6.6 billion people, each person's share of Earth's productive capacity is 1.6 hectares.
That was the easy part.
By current estimates, Canadians consume the equivalent of 7-8 hectares per person.
How is this possible?
1. The developing world consumes far less. For instance, the average Indian consumes the equivalent of 0.8 hectares.
2. A significant portion of Canadians' consumption is of non-renewable resources (fossil fuels, minerals) which, by definition, cannot be included as part of Earth's productive capacity.
3. The consumption, and volume of waste products output by Canadians' consumption, is actually overloading Earth's productive capacity. Witness the degradation of fresh water resources, depletion of fisheries, and rapid accumulation of greenhouse gases. By the way, Earth's processes for re-absorbing and converting those wastes is included as part of its productive capacity.
So, the ecological footprint of this light fixture can only be calculated by assuming that its manufacture, use, and disposal, consumes renewable resources.
Renewable energies can be used to power the light, which is actually its greatest impact.
The wood would come from sustainable forestry.
The metals must be reused or recycled, and renewable energies consumed to do so.
The PVC comes from our most valuable future resource: landfill. ;-)
Since the use phase so outweighs the production and disposal phases (and that I have no data to use), I have only calculated the footprint of the use phase.
Yearly consumption by the CFL bulbs is 62.4 kWh.
Yearly consumption by the incandescent bulbs is 249.7 kWh.
I used a spreadsheet available from Redefining Progress to calculate the footprint, and have attached it below.
Briefly, 62.4 kWh per year consumes .014 hectares. That equates to 1/115th of each person's 1.6 hectare share of Earth's productive capacity.
In contrast, 249.7 kWh per year consumes .055 hectares. That equates to 1/29th of each person's share of Earth's productive capacity.
(These share figures assume that there is only one person in the household.)
I must confess to being inspired by Bruce Sterling, and his book "Shaping Things", for attempting this project.
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Nice to read!