Your post brought up an excellent and concerning point, which is that we, as a consumer society, use more raw wood than is grown in the world. I wonder if, for your exploration, you could look into different aspects of demand? I would think there are at least two categories, one being a need for freshly cut lumber, and the other for recycled wood. See what industries genuinely have a need for lumber, and which ones currently do use what is recycled. You could also maybe, based on your research, analyze what industries you think could potentially replace lumber with recycled wood products, and which industries use a larger percentage of lumber, and therefore which ones would have the greatest effect on reducing the amount of lumber used.
The UK has a wood recycling association that you can check out at woodrecyclers.org as a base point. Also, Hadfield Wood Recyclers (hadfield.co.uk), is a company that sells recycled wood products. On the smaller scale, they have a product that acts as a replacement for animal bedding. On the larger scale, their products can be recycled into panel board, arena surfaces, and play area surfaces.
There are so many types of recycled wood also, from lumber to flooring to shredded wood. There are two costs associated with products like these, which are the monetary value, and the environmental value. Maybe evaluating these points will help you make some interesting and valuable discoveries. Best of luck to you, I think this is great!