Resource Issues and Life Cycle Assessment (LCA)

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

• 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

Table 2.3 Ecological Footprint of average Canadian (Wackernagel and Rees 1996)

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 CO2

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

Consumption WorldwideConsumption 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

Vehicles per 100 people 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

Ecological Footprint 4.3 5.1 0.4 1.8

(hectares/ person)

Table 2.4 Consumption characteristics and Ecological Footprints of various countries andworld average (Wackernagel and Rees 1996)

Global Footprint Network, 2005. National Footprint and Biocapacity Accounts, 2005 Edition.Available at http://www.footprintnetwork.org.

Ecological Footprint

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

Raw Materials Acquisition

Materials Manufacture

Product Manufacture

Product Use or Consumption Disposition

Energy Energy Energy Energy Energy

Wastes Wastes WastesWastes

Reuse

Product Recycling

General Materials Flow for “Cradle-to-Grave” Analysis of a Product System

General LCA MethodologyI. 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:

– 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