LCA Exam 1 Questions and Answers Graded
A+
What should the functional unit include? identification of the product, amount of the
function (quantifiable unit), and time value
What is the main point of a functional unit? They allow for fair comparisons of different
technologies by focusing on the function of the product/process/system
Are functional units needed for non-comparative LCAs? Yes, they are still needed for the
basis of data collection, but choice of unit is not as critical since there is no comparison
Do functional units have inventory items or environmental impacts in them? NO!
Criteria for inputs/outputs Mass, economic value, environmental impact (if below a
certain value, they are excluded)
Keystone pipeline concerns oil spills, CO2 emissions, extraction phase
,Attributional LCA answers questions like "what are the env. impacts due to inventory
flows under current conditions"; for ex. examining env. impacts of corn ethanol vs. soybean
biodiesel
Consequential LCA answers questions like "how will env. impacts beyond the immediate
system change in response to decisions which cause marginal changes in inventory flows?"; for
ex. considering consequences of subsidy for biodiesel, causing farmers to grow soybeans instead
of corn
What are attributional LCAs based on? strict relationships between inputs and outputs;
results produced with known levels of accuracy and precision
What are consequential LCAs based on? highly dependent on economic models
representing relationships between demand for inputs, prices, supply, and markets effects of
products; rarely provide known accuracy or precision
What type of LCAs do we study in our class? Attributional, since it is more engineering
based (rather than economics based)
, What is the LCA inventory? a list of all of the inputs and outputs within the scope
boundaries
Is it required to separate inventory items in life cycle phases? No, but it is commonly done
to allow the env. effort to be analyzed phase by phase to know where to take action
Types of inventory data foreground (primary) vs background (secondary)
Where should the type of data be specified? in the Goals and Scope section of the LCA
Foreground (primary) data sources interviews, mass/materials data, Bill of Materials
Co-products outputs that are not the primary output, but still have use or value
Allocating inventory inputs and outputs that are allocated or shared between products and
co-products
Allocation by product distribution for ex.: 20% product A, 40% product B, 40% product C
A+
What should the functional unit include? identification of the product, amount of the
function (quantifiable unit), and time value
What is the main point of a functional unit? They allow for fair comparisons of different
technologies by focusing on the function of the product/process/system
Are functional units needed for non-comparative LCAs? Yes, they are still needed for the
basis of data collection, but choice of unit is not as critical since there is no comparison
Do functional units have inventory items or environmental impacts in them? NO!
Criteria for inputs/outputs Mass, economic value, environmental impact (if below a
certain value, they are excluded)
Keystone pipeline concerns oil spills, CO2 emissions, extraction phase
,Attributional LCA answers questions like "what are the env. impacts due to inventory
flows under current conditions"; for ex. examining env. impacts of corn ethanol vs. soybean
biodiesel
Consequential LCA answers questions like "how will env. impacts beyond the immediate
system change in response to decisions which cause marginal changes in inventory flows?"; for
ex. considering consequences of subsidy for biodiesel, causing farmers to grow soybeans instead
of corn
What are attributional LCAs based on? strict relationships between inputs and outputs;
results produced with known levels of accuracy and precision
What are consequential LCAs based on? highly dependent on economic models
representing relationships between demand for inputs, prices, supply, and markets effects of
products; rarely provide known accuracy or precision
What type of LCAs do we study in our class? Attributional, since it is more engineering
based (rather than economics based)
, What is the LCA inventory? a list of all of the inputs and outputs within the scope
boundaries
Is it required to separate inventory items in life cycle phases? No, but it is commonly done
to allow the env. effort to be analyzed phase by phase to know where to take action
Types of inventory data foreground (primary) vs background (secondary)
Where should the type of data be specified? in the Goals and Scope section of the LCA
Foreground (primary) data sources interviews, mass/materials data, Bill of Materials
Co-products outputs that are not the primary output, but still have use or value
Allocating inventory inputs and outputs that are allocated or shared between products and
co-products
Allocation by product distribution for ex.: 20% product A, 40% product B, 40% product C
