When you bought your last mountain bike, did you inadvertently finance its makers to rape and pillage the earth?
If you bought your bike new, the correct answer is “yes.” Every part of that bike came out of a hole somewhere on earth. If your bicycle frame is made of carbon, that hole is 12 to 30 inches wide and oil comes out of it. If it is aluminum or steel, well, those holes can be seen from space. But, the journey only begins there. There are emissions created by hauling the materials to where they are needed. Trans-continental pipelines, excavation equipment, trains, long-haul trucks, cargo ships, and oil tankers move raw materials to processing plants. Add in the pollution and energy draw of the foundries, refineries and chemical factories that turn raw materials into usable forms, and then realize that the places where metal, plastic, and carbon fiber are made are most likely on a different continent than where your bicycle was manufactured.
If your bike is made from metal, it came from a big hole in the ground. If it is carbon, it came out of an oil well.
Once those materials are produced, an army of container ships continuously ply the globe, dropping off aluminum, carbon fiber, thermoplastic pellets, and steel to the places where frames and components are manufactured. Some of those same ships will then be loaded with containers of bicycles, destined primarily to European and North American populations who are hungry for high tech mountain bikes, but have lost their appetites for the dirty work that is required to create them.
https://www.pinkbike.com/news/alumi...om-fiction-in-the-frame-materials-debate.html