What does 400 ppm look like? — Carbon Visuals

400 parts per million. Why is the figure in the news? Can we help people make 400 ppm meaningful for themselves by showing what it looks like?

Carbon Dioxide Levels Chart

Climate Change Indicators: Atmospheric Concentrations of Greenhouse Gases

Carbon dioxide levels cross 400 ppm threshold, likely highest in millions of years

World Passes 400 PPM Carbon Dioxide Level Milestone; Experts Say 'We're Stuck' With Global Warming - The Associated Press - May 10, 2013 - Global Warming - Climate Change - Global Environmental

Planet Health Report: AIR

What Earth was like last time CO2 levels were as high as today

392 parts per million

Global Carbon Dioxide - 400 ppm, Thursday 9 May 2013 the da…

The Rise of Carbon Dioxide in a Single Video - Universe Today

Graphic: Carbon dioxide hits new high – Climate Change: Vital Signs of the Planet

Humans didn't exist the last time there was this much CO2 in the air — Grist – Coyote Gulch

University of Oxford - The global average of carbon dioxide in the atmosphere, measured in parts per million (ppm). 📈, Our World In Data #TruePlanet #COP26Glasgow #COP26