Red spikes coincide with driving through Sydney harbour tunnel on way to work and back. Usually have windows open when driving car except for in tunnels. It was only me in car yet it still fascinates me how quickly CO2 levels rise in the car with air con recirculating. #FridayAirDay #CleanTheAir

RE: https://bsky.app/profile/did:plc:xy6pzq73jzsyx743cejhrrly/post/3m5k4b6se4327