Adrienne Murray travels to the Arctic Circle to find out how the community of Longyearbyen in Svalbard is shifting to clean energy, and Paul Carter takes a train journey to see how hydrogen technology can help to clean up carbon emissions of diesel engines. Plus, Joe Tidy investigates the world of AI models, and Lara Lewington tests out a device to measure cardiorespiratory fitness without the exercise.

The show’s own verdict is on its page.