Yesterday, a colleague from the geology department described an A-Level physics question he’d noticed while invigilating earlier that week.
An avid cycler and environmentalist, he was somewhat aghast to discover a question that implied CO2 emissions could be reduced if cyclists did everyone a favour, and journeyed in cars like the rest of us.
The question was from this year’s Edexcel GCE course in physics (Monday 20 May 2013, 6PH01/01, Physics Advanced Subsidiary Unit 1: Physics On The Go, Question 13).
Below is a copy of the unanswered question, followed by my handwritten solution.
Question
Solution
As you can see, the question suggests CO2 emissions actually increase due to cyclists slowing down motorists!
The reduction of CO2 emissions due to the cyclists not using their car is outweighed by the extra CO2 emission caused by them delaying 3 motorists.
Is this the product of a passive-aggressive petrol-headed examiner? Or, is it a sound warning to anyone who thinks the business reducing carbon emissions is a simple calculation?
I once asked a friend who was dutifully washing yoghurt pots after a dinner party whether the energy required to deliver that volume of purified water was greater than the energy saved through recycling the pots. A steely stare was the reply.
But this is the sort of question we must put to each other if emissions are to effectively reduce. Good intentions do not feature in the physical variables of the greenhouse effect.
Speaking of fruitless good intentions, that reminds me of another colleague who teaches economics, and is an active Green Party member.
Earlier this week, he used the staff-room telephone to place an order for gas. Revealing that he resides in The-Middle-Of-Nowhere (a backwater of the Empire that I can only presume suffers from over-population, judging from how often people tell me they live there), he explained that wiring and plumbing is yet to reach his location.
When I asked how much CO2 he estimated was emitted in the delivery of these gas canisters, he instead tried to calculate exactly how many oil executives he would need to murder to remain carbon neutral. Typical Green Party response, I’m sure you’ll agree.
Perhaps I should write an A-level question about that…
