400ppm
World ‘beyond return’ of historic carbon dioxide milestone
Record surge in CO2 through 2015 and 2016 saw atmospheric concentrations rise fast than 2 parts per million average to well above 400ppm
‘Time running out’ says UN as CO2 levels hit record April high
NEWS: WMO chief says new data shows world leaders must urgently reach a deal to limit atmospheric carbon dioxide levels
400ppm: the milestone that puts Earth in the “danger zone”
FEATURE: The Earth entered uncharted territory when CO2 levels hit 400ppm for the first time. So what does the milestone mean?
Funding crisis places future of Keeling Curve in jeopardy
The Keeling Curve has measured atmospheric CO2 since 1958, but without urgent funding climate science would lose a vital tool
2013 in review: a year of fracking, wacky weather and soaring CO2
The RTCC team reflect on a year which broke records, stunned climate experts and left Russell Brand steaming
Figueres: 400ppm a sign leaders must address climate change
United Nations climate chief says news world has hit 400ppm CO2 target should encourage governments to boost emission reduction ambitions
McKibben: 400ppm is a grim climate landmark
As world passes an atmospheric concentration of CO2 not seen for more than 3 million years, there are calls for politicians to pay more attention to the science
Can 400ppm spark us into climate action?
Hitting the 400ppm level of atmospheric CO2 can be more than symbolic, it can be a rallying call too, writes Johan L. Kuylenstierna, executive director of the Stockholm Environment Institute