All this leaves me with The Big Question:
Should I bring the boots home to the USA at the end of my trip?
The Carbon Footprint
I put together a spreadsheet using data from the EPA (US Environmental Protection Agency). I learned 20 pounds of carbon dioxide (on average) would be produced by flying my boots back home to Minneapolis. At first, I thought the decimal point was in the wrong position.
This number became more credible when I considered:
One US gallon (0.8 imperial gallons) of aviation fuel produces 21.2 pounds of carbon dioxide.
The total fuel capacity of an Airbus 330-300, the plane I will be flying long-haul, is 25,765 gallons.
There are two takeoffs: the boots will be lifted almost 14 miles.Ultimately, the number is just an estimate based on averages, and the plane will fly with or without the boots. But it is a fact: my boots at 36,000 feet would increase the amount of carbon dioxide in the atmosphere.
My Boots: Decision Time
I've had the boots over two years, the soles are worn and are approaching the point they will not provide good traction. The volcanic trails of Japan and Hawaii have been particularly hard on the heels, causing some shredding.
I could bring the boots home and have them rebuilt. I could pay upwards of $80 and end up with a substandard pair.
I already have replacements, bought on sale for $150. Boots are just too important, so I'm happy to buy a new pair every two or three years.
Today there is enough tread for one more multi-day hike. Before I fly home, I'll toss the boots and avoid adding to aviation-caused atmospheric carbon dioxide.
Maybe someone will use my boots as planters.
Note: The graph in the infographic at the top of this post shows data for the atmosphere near the summit of Hawaii Big Island's Mauna Loa (13,678 feet). This is some of the cleanest air on the planet.