How do we know if the global warming in the twentieth and twenty-first centuries is an anomaly, or just part of a natural cycle?
Tree ring growth can be absolutely dated, and mapped onto a historical timeline. This tree ring data shows that the temperature changes we have experienced in the twentieth and twenty-first centuries are unprecedented in terms of speed, and are global.
About our experts
Professor Mary Gagen, of Swansea University’s Geography Department, measures tree ring data – ‘weather stations across the world’ - to find out what has happened to our climate across the planet over the last few thousand years.
Listen or watch on your preferred platform
There are multiple ways that you can listen to, or even watch, the Exploring Global Problems podcast series. Just click on the links below which will take you to your preferred platform. To find out more about how to listen visit our podcast help page.