The canary’s work as a measure of subtle atmospheric change didn’t end in the coal mine. Environmental scientists frequently study birds, using their shifting and adaptable songs as a way to gauge the impact of human development on animals.

Seeking to visualize potential problems that could arise from an increased concentration of carbon dioxide in the atmosphere, Singing Sentinels by Liam Young of Tomorrow’s Thoughts Today safely exposes a room of songbirds to gradually rising levels of CO2. As the ratio swings toward heavier doses of carbon dioxide, you can hear the singing slightly change and, in some cases, stop altogether. By the time the “pollution DJ” hits the 1,000 parts per million number — which some predict we could hit by 2100 — things get awfully quiet.

(Via Liam Young)