Question

9. A brand of refrigerators are manufactured in Shanghai, China and transported to the client’s warehouse in Chicago, USA for retail distribution. What is the carbon footprint per refrigerator if sent by Option A & Option B? Shipping weight including packaging of each refrigerator unit is 90 kg.

a) Air freight from Shanghai to Chicago, distance is 11,500 km. And then road transport by large truck from Chicago airport to warehouse, distance travelled is 100 km.

b) Sea freight from Shanghai to Seattle, distance is 9,200 km. Then shipped on rail transport from Seattle to Chicago rail yard, distance travelled is 3,400 km. And finally

transported to warehouse on a large truck, distance travelled is 30 km.

Answer 1

The carbon footprint is a carbon emission in Kg per year.  

For traveling it is kg per km or gram per km.

For

flight = 133 g

truck = 75 g

sea = 12 g

rail = 41 g

(above figures are not correct, these figures can change for a different trip, I have taken an average )

Case a)

carbon emission = 11500km * 133 g/km + 100 km * 75 g/km = 1537000 g = 1537 kg

carbon footprint = (carbon emission/mass of refrigerator )=1537 /90 = 17.08

Case b)

carbon emission = 9200 km*12 g/km + 3400km *41 g/km + 30km * 75g/km = 252050 g = 252.050 kg

carbon footprint = (carbon emission/mass of refrigerator )= 252.050/90 = 2.8