Sharing - we need to share more.
Take tools for example:
Pretty much everyone that I know has an electric hand drill.
These drills have a number of things in common:
1: they are almost all terrible quality.
2: they run for a total of about one hour per year - if that.
Here in Germany there are about 40 million housholds, if only every fourth owns an electric drill that's 10 million crappy drills in Germany alone, assuming a 10 year life span that's about a million Liters of rubbishy drills per year landing in African landfills. (Yes, I know I'm exaggerating, Germany has a lot of good recycling policies in place.)
So, why does everyone have to have their own poor quality tools? Why not get together and buy good quality basic tools in a group. It might be a group of neighbors, the local maker/hacker space, students rooming together, a group of colleagues, local gardening association or your church. It doesn't matter.
Good quality tools are often made in countries where rules governing environmental impact ensure that that impact is far less than for cheap tools made elsewhere.
Good tools last longer and are often repairable. I can still get parts for some manufacturers 20 years after the Tool has been replaced by another model. This makes them still more environmentally friendly and economical in the long term.
Now, of course there are Commercial Tool Rental places and they are great for specialist tools, but probably aren't as 24/7 accessible as the local maker space or your student rooms toolbox.
Sharing tools offers an opportunity to share knowledge about using them properly, improving results, safety and the life of the tool itself. Sharing is a social affair, it brings people together.
Oh, and one more thing - sharing is good for your soul! ;)