Crossing the 400 ppm milestone – it means nothing, and everything

For the first time in recorded history, the atmosphere’s concentration of CO2 has gone past 400 parts per million in at least one part of the world. And while the difference between 399 ppm and 400 ppm is not meaningful, it does symbolise that much more needs to be done.

Climate Central


SMS Code Sent…

We have sent you a code via SMS to {{user.DayPhone}}

please enter this code below to activate your membership

If you didn't receive SMS code please

Log in to access this content

Looks you are already a member. Please enter your password to proceed

Hi {{ user.FirstName }}

Verify your mobile number to unlock a FREE trial

Looks like you've already taken a free trial

Please sign up for full access

Updating information

Please wait ...

Related Articles