Our damaging addiction to concrete.
Concrete is the second-most consumed substance in the world and causes much environmental damage. Despite this, it's needed for essential infrastructure and, paradoxically, will be needed even more to protect against climate change.
Alongside all of this, it has a lifespan of about 100 years, which means much of our infrastructure is hitting that age limit and starting to rot.
This is a fascinating article on our addiction to concrete and the harms that come with it.