Whole-Life Accounting Changes the Answer

Lab Brief #4

🎯 Your mission

Master the concept. Use it tomorrow.

⚡ The twist

What the body does in one minute is wilder than any cartoon.

What you'll learn

Comparing two options honestly means counting manufacture, use and disposal together rather than stopping at the moment of use. An electric car begins with a larger manufacturing debt because of battery production and repays it over tens of thousands of kilometres, so whether it wins depends on how far it is driven and on how the electricity was generated. A tailpipe comparison is not a wrong number; it is the right number inside the wrong boundary.

Key words

life cycle assessment
Accounting for the impacts of a product from raw material through manufacture and use to disposal.
system boundary
The edge drawn around what a comparison counts, which decides what the comparison can show.

Make a hypothesis first

Guess: how does the body solve this problem?

Say your guess out loud — then find out if you were right.

Step 1 of 4 · Read

Think about what you just learned: say what "life cycle assessment" and "system boundary" mean in your own words before you start.

Step 2 of 4 · Do

Build a break-even graph for two cars: plot cumulative emissions against distance driven, starting each at its manufacturing figure and adding its per-kilometre rate. Read off the crossover distance, then redraw it with a higher-carbon electricity supply.

Step 3 of 4 · Observe

Record what actually happened, including anything that did not match what you expected.

Step 4 of 4 · Record

Write a conclusion that answers the question this lesson opened with, and state your uncertainty.

Question 1 of 3

A tailpipe-only comparison of two cars is misleading because it uses the wrong:

How sure are you?😐 maybe

Question 2 of 3

An electric car's emissions advantage depends most on:

How sure are you?😐 maybe

Question 3 of 3

Life cycle assessment counts impacts from:

How sure are you?😐 maybe

Mind = blown

🐙 An octopus has 9 brains and 3 hearts.

Nice work!

You got 0 of 3 right.

Next: Biodiversity Loss Is a Rate Argument All lessons

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✨ More to explore

🌍 Where you see this in real life: Your own body is doing this thousands of times every second.

🏆 Stretch challenge (try it this week): Find one thing about your body that's different from a friend's. Wonder why.

👨‍👩‍👧 For the dinner table: “Tell me something you noticed about your own body today.”

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Whole-Life Accounting Changes the Answer

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