The world economy needs inputs of raw materials. This includes biomass, minerals, metals, fossil fuels, and construction materials. In the first half of the 1900s, this doubled from 7 billion tons to 14 billion tons. It reached 35 billion tons in 1980, 50 billion tons in 2000, and 92 billion tons in 2017. Here's a cool website that shows material flows: - http://www.materialflows.net/ Here's a graph from the book [[Reference Notes/Less is More]]: ![[Pasted image 20210630105036.png]] The black line shows what scientists consider to be the maximum sustainable threshold: 50 billion tons. - Bringezu, Stefan. “Possible Target Corridor for Sustainable Use of Global Material Resources,” 2015, 30. We are on course to consume 200 billion tons per year by 2050. That is 4 times over the safe boundary. [[Reference Notes/Less is More]]