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?

El Niño Could Push CO2 Permanently Above Milestone

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

Carbon dioxide in atmosphere at record level

CO2 levels higher than any point since the evolution of humans

What is causing the increase in atmospheric CO2?

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

Greenhouse gas concentrations

Carbon Dioxide Could Reach Unseen Heights – 410 PPM – This Month

Carbon dioxide hits 400 ppm for the first time in human history