How we know
The commitment to truth
This whole project rests on one bet: that understanding the world honestly is how we reduce its suffering. That only holds if the understanding is true. So here is how these figures are made, where they come from, and how you can check every one of them yourself.
Every number here is a rounded, honest approximation, not a citation. "Roughly 600,000 malaria deaths a year" is truer to the state of knowledge than a false-precise "618,347", because the real figure carries uncertainty a precise number hides. Where sources genuinely disagree, we say so. We would rather be roughly right than precisely wrong.
Each problem links straight to Our World in Data's charts for its topic, so you never have to take our word for it. The core figures draw on the same public sources researchers use:
Our World in Data · the World Bank · the World Health Organization · the UN (Population Division, IGME, UNESCO, UNHCR) · Gapminder · GiveWell and ACE for cost-effectiveness · NOAA for the climate record.
Projections past today are drawn dashed and labelled as forecasts, never facts. Problems without honest data say so rather than inventing it. The After AGI page is explicitly informed speculation. The world map shades by region, not fabricated country numbers. Refusing to overclaim is part of telling the truth.
Today these figures are reviewed and updated by hand. The next step is to have the headline numbers refresh themselves from Our World in Data on a schedule, with the date of the latest figure shown in the open. Truth isn't a state you reach once; it's a practice you keep. That work is underway.