We often talk about rebuilding after a disaster, but we leave so little thought for rthe materials needed. Have you ever thought about where all the rubble goes after a war or a flood?

That’s the question that led Guilherme Iablonovski, a geospatial data scientist at the UN Sustainable Development Solutions Network, to dedicate his career to mapping matter itself — from concrete and steel to the global flow of sand, food, and everything in between.

In this week’s episode of 15-Minute Maps, Guilherme joins me to talk about:
Why the world needs a “map of matter” — a way to trace what materials are where, and where they move.

How cities have a metabolism, just like living beings — taking in, storing, and expelling materials in measurable flows.

What happens to all that material when a city is bombarded or flooded — and how understanding this could make rebuilding faster, cheaper, and greener.
How consumption habits in places like Paris can have invisible footprints across the world.

And why mapping matter could be key to tracking progress toward the Sustainable Development Goals (SDGs) — especially SDG 11 (Sustainable Cities) and SDG 12 (Responsible Consumption and Production).