Transcript Resource Issues and Life Cycle Assessment (LCA) Lecture C

Resource Issues
and
Life Cycle Assessment (LCA)
Lecture C
Starting
• Among other things, sustainability requires:
– Resources
– Environmental quality
• This lecture covers these two issues
• Terminology, new ideas, some tools
Issues and Thoughts
• Rapidly industrializing world is consuming
resources at unprecedented rate
• Nonrenewable resources are being rapidly depleted
or rich veins are depleted
• Renewable resources are being depleted faster than
the generation rate.
• Question: How do we conserve nonrenewable
resources and regenerate renewables while
protecting biodiversity?
Some Terminology
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Carrying Capacity
Ecological Footprint
Ecological Rucksack
Materials Intensity Per Service Unit (MIPS)
Factor 4 and Factor 10 (and Factor ‘x’)
Hubbert’s Curve and Hubbert’s ‘Pimple’
Dematerialization , Deenergization,
Decarbonization
Key Resources
• Air: degradation by human activities
• Water: Surface, groundwater, aquifers, fossil water
• Agricultural Soil: regeneration rate (best case) is 10
tons/hectare (1 mm deep soil over a hectare)
• Nonrenewable resources (the world’s geologic
endowment): fossil fuels, ores
• Renewable resources (solar driven): forests,
biomass, soil, fisheries
• Intangible resources (no upper limit): open space,
beauty, serenity, genius, information, diversity,
satisfaction
Resource Consumption Patterns
Oil Production
Actual Oil and Gas Consumption
Hubbert’s Pimple - Oil Consumption
Carrying Capacity
• ...the maximum population that can be sustained in a
habitat without the degradation of the life-support
system.
• An environment's carrying capacity is
its maximum persistently supportable load
(Catton 1986).
• sustained, instantaneous, maximum, optimum, human,
physical, hydrologic, global, biophysical, real, and
natural carrying capacity
• Knowing the carrying capacity of an ecosystem is an
important planning tool because it provides information
on when the services of the ecosystem are being
exceeded, leading to its possible collapse and the total or
partial loss of the services of the system
Carrying Capacity Constraints
• Human carrying capacity depends on both natural
constraints and cultural choices
• Natural constraints include the distribution and
availability of potable water, the quality of soil,
ecosystem biodiversity, weather, terrain, and the
occurrence of natural disasters
• Cultural constraints: economic system, political
institutions, values, tastes, fashions, religion, family
structure, educational concepts, and the handling of
externalities
Arguments against Carrying Capacity
• Reserves of natural resources are predicated on the
technology developed for their extraction, consequently
technology ultimately defines the economics of resource
extraction
• Technology allows the development of substitutes for
resources that become relatively scarce
• Less resources are needed each year to produce goods and
services due to increasing knowledge and newer
technologies
• Effects of competition as various manufacturers or
suppliers vie to provide the goods and services
demanded by companies and individuals
Human Carrying Capacity
• UN forecast of between 7.7 and 12 billion
people in the year 2050
• In 2000 the world’s population was 6.1
billion with an annual growth rate of 1.7%,
creating a doubling time of 42 years
• Wide variety of estimates as to how many
people the world can support
Ecological Footprint
• Ecological Footprint (EF) is the quantity of land needed to
support a person, population, activity, or and economy
• EF uses five major categories of consumption to compute
the corresponding land area: food, housing, transportation,
consumer goods, and services
• London’s impacts on ecosystems when analysis indicates
that its EF is 120 times its physical footprint
• The Dutch have an EF 15 times greater than its actual land
area
• The available land per person to produce the required
goods and services and assimilate their waste is about 1.5
hectares. Americans are using 3x their ‘Earth Share.’
Ecological Footprint of a Canadian
Consumption
Footprint (hectares)
Category
Energy Degradation Garden Crop Pasture Forest Total
1 Food
0.33
0.00
0.02
0.60
0.33
0.22
1.30
2 Housing
0.41
0.08
0.002
0.00
0.00
0.40
0.89
3 Transportation
0.79
0.10
0.00
0.00
0.00
0.00
0.89
4 Consumer Goods
0.52
0.01
0.00
0.06
0.13
0.17
0.89
5 Services
0.29
0.01
0.00
0.00
0.00
0.00
0.30
TOTAL
2.34
0.20
0.02
0.66
0.46
0.59
4.27
Energy = fossil fuel energy expressed in land area required to sequester resulting CO 2
Degradation = degraded land or built-up environment
Garden = land for vegetable and fruit production
Crop = land for crops
Pasture = area for dairy, meat, and wool production
Forest = Prime wooded land for timber and paper production *
*
Assumes harvest of 163 cubic meters of wood per hectare every 70 years
Table 2.3 Ecological Footprint of average Canadian (Wackernagel and Rees 1996)
Consumption Worldwide
Consumption per Person
Canada
USA
India
World
CO2 emissions (tonnes/year)
15.2
19.5
0.81
4.2
Purchasing power ($US/year)
19,320
22,130
1,150
3,800
47
57
0.2
10
Paper consumption (Kg/year)
247
317
2
44
Fossil energy use (Gigajoules/year)
250
287
5
56
Fresh water withdrawals (m3/year)
1,688
1,868
612
644
4.3
5.1
0.4
1.8
Vehicles per 100 people
Ecological Footprint
(hectares/person)
Table 2.4 Consumption characteristics and Ecological Footprints of various countries and
world average (Wackernagel and Rees 1996)
Ecological Footprint
Global Footprint Network, 2005. National Footprint and Biocapacity Accounts, 2005 Edition.
Available at http://www.footprintnetwork.org.
http://www.bestfootforward.com/index.htm
Ecological Rucksack and MIPS
• Ecological Rucksack: “The total weight of
material flow ‘carried by’ an item if
consumption in the course of its life cycle.”
• MIPS (Materials Intensity per service unit):
An indicator based on the material flow and
the number of services provided.
• Reducing MIPS is equivalent to increasing
resource productivity
Ecological
Rucksack
Diagram
Some other ecological rucksacks
•Coffee maker 298 kg
•toothbrush about 1.5 kg
•plastic bucket 26 kg
•silver chain 20 kg
•12 wine glasses 6 kg
•5-gram gold ring 2000 kg
•wooden beads 0.5 kg
(Simonen 1999)
Plastic or Cotton Bag?
•The plastic bag (PE plastic, 18 g) has the following ecological
rucksack: abiotic and biotic material 0.1 kg, water 1.17 kg, air
0.04 kg, earth 0 g.
•The cotton bag (54 g) has the following ecological rucksack:
abiotic and biotic material 1.277 kg, water 214.704 kg, air
0.216 kg, earth 3.402 g. (Vähä-Jaakkola 1999, Wuppertal
Institute)
•If you use the cotton bag for a year and buy a plastic bag once
per year, which is the better buy?
•Use the Ecological Rucksack to determine the solution
Factor 4 and Factor 10
• Factor 4: the idea that resource productivity
should be quadrupled so that wealth is doubled
and resource use is cut in half. “Doing more with
less.” Result: substantial macroeconomic gains.
• Factor 10: per capita materials flows in OECD
countries should be cut by a factor of ten.
Requirement to be able to live sustainably in the
next 25-50 years.
• Note: technology for Factor 4 already exists!!
• Facto x: Going beyond Factor 4 and Factor 10
GM Ultralight Car
Concluding Thoughts on Resource Issues
• Adequate resources are essential for sustainability
• Ecological systems must be protected and restored
during/after resource extraction
• Beware of the Ecological Rucksack!
• Renewable resource extraction rate < regeneration
rate
• Dematerialization and deenergization are essential
Life-Cycle Analysis (LCA)
• An evolving, multidisciplinary tool for measuring
environmental performance
• A “cradle-to-grave” systems approach for understanding the
environmental consequences of technology choices
• Concept: all stages of the life of a material generate
environmental impacts: raw materials extraction, procesing,
intermediate materials manufacture, product manufacture,
installation, operation and maintenance, removal, recycling,
reuse, or disposal
General Materials Flow for “Cradle-to-Grave”
Analysis of a Product System
Energy
Raw Materials
Acquisition
Energy
Materials
Manufacture
Energy
Product
Manufacture
Energy
Energy
Product Use or
Consumption
Disposition
Wastes
Wastes
Wastes
Wastes
Reuse
Product Recycling
General LCA Methodology
I. Goal Identification and Scoping: What is the
purpose of the LCA? What decision is the LCA meant
to support? Where are the environmental impact
boundaries to be drawn? Are all impacts, secondary,
tertiary included?
II. Four-Step LCA Analytic Process
1. Inventory Analysis: environmental inputs
2. Impact Assessment
3. Impact Evaluation
4. Improvement Assessment Step
1. Inventory Analysis
• Identify and quantify all environmental
inputs and outputs over the life cycle
– Inputs: energy, water, other resources
– Outputs: Emissions and releases to air ,water,
land
• Includes uncertainty ranges
2. Impact Assessment
• Classify inventory items by impact: greenhouse
warming gases, ozone depletion, soil erosion,
biodiversity, human health, natural resource
• Data converted to equivalency factors and impact
per functional unit of material
– Greenhouse warming: Halogenated compounds > CH4
> CO2
– CO2 equivalents per square meter
– Allow direct numerical comparisons between
materials
3. Impact Assessment
• Impact assessment results are normalize
into an overall environmental score for each
alternative
• Result: relative environmental scores for
each alternative that can be ranked
4. Improvement Assessment
• Review the results to determine key impacts
• Evaluate process alternatives to reduce
impacts
• Consider Design of the Environment and
Industrial Ecology approaches
SETAC
• Society for Environmental Toxicology and
Chemistry
• Standardized LCA approach
• International society dedicated to LCA
Example: Cloth vs. Disposable Diapers
• LCA of the comparative environmental impacts of using
cloth or disposable diapers
• Single use, home-laundered, commercial service
• Resource and environmental profile analysis (REPA)
• Assessed at each stage:
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Energy consumption
Water usage
Atmospheric and waterborne emissions
Solid waste
Conclusions - LCA
• Standard method for assessing the environmental
performance of product manufacturing
• Large array of data – inputs and outputs
• Complex and difficult to use for comparing
options
• Excellent tool for companies to use to assess how
they can improve their production