Carbon dioxide levels hitting historic high is the final wake-up call - The Week

At 415 ppm, carbon dioxide level is at highest ever in human history

Weather, Sea Rise+ Global Warming - So What?

Visualizing Global Per Capita CO2 Emissions

Climate Milestone: Earth's CO2 Level Passes 400 ppm

Do high levels of CO2 in the past contradict the warming effect of CO2?

Quick fact rapidly rising CO2 levels Related Info – Climate Solutions Advancement Network (ClimateSAN)

What is an acceptable level of CO2? - Quora

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

Do high levels of CO2 in the past contradict the warming effect of CO2?

I'm living in a carbon bubble. Literally., by Joel Jean

Carbon dioxide levels hit highest mark in human history, despite coronavirus - The Washington Post

CO2 Concentrations Hit Highest Levels in 3 Million Years - Yale E360

Carbon Dioxide Through Time EARTH 103: Earth in the Future