How do we track a changing climate?
Among all the charts on our site, the one here reaches further back in time than almost any other: the concentration of CO₂ in Earth’s atmosphere over the last 800,000 years.
For most of that time, CO₂ rose and fell between roughly 180 and 300 parts per million (ppm), driven by natural cycles in Earth’s orbit. We know this from cores of Antarctic ice, which trapped tiny bubbles of ancient air as it formed.
By 2025, the concentration — now measured by NOAA’s Global Monitoring Laboratory — reached 426 ppm, higher than at any point in that record. Concentrations over the past decade have been rising at 2 to 3 ppm each year.
This dramatic increase in CO₂ is mainly from human activity; this and other greenhouse gas emissions are the primary drivers of current climate change.
CO₂ concentration is just one of the indicators we use to track a changing climate. Others include global temperatures, ocean heat content, and snow cover. Each of these is compiled by a dedicated scientific institution, from the UK’s Met Office Hadley Centre to NOAA in the US.
Our colleague Pablo Rosado recently updated our climate charts with the latest data from these sources, something he does every month.
Trump Bingo: The Likes of Which You’ve Never Seen
On Thursday the President will once again stand in front of a microphone and produce sounds. Not sentences. Sounds. And since nobody’s listening to the content anyway, we might as well make ourselves useful.
So here it is: the Gandalv Trump Bingo card. The rules take three seconds to learn. He says “Tremendous”, you cross it off. He says “Many people are saying”, you cross it off. Five in a row is Bingo. The full card is a Total Landslide, Frankly, at which point you may pour yourself something strong.
The centre square is a free space. It says “China”. That’s not a joke, it’s statistics.
Best of all, the card is fully reusable for every speech from now until the end of time. The world changes. The material never does.
Good luck on Thursday. You won’t need it.
I really don't know why so many legislators in the US and Canada have failed to pick the scientific and health-forward option out of the two options available. They had a 50/50 chance of getting it right and got it wrong. It really speaks to where we're at as a society.
@RobSilver Agreed. I suspect many in favour of permanent DST don’t even realize it how bad winter work/school mornings will be until it hits. Everyone is only thinking about the late summer evenings.
Players wearing their own team jerseys is so much better than everyone wearing the same uniform. It gives the All-Star Game more personality and makes it feel like a true celebration of every team. Glad they went back to it. #AllStarGame
GOODBYE . My friends, I’m just going to walk quietly away from Twitter for now . I am not happy with what’s happened at Twitter & I’m not happy to be in a place that is so angry & divisive . But I’ll still be alive on Instagram. https://t.co/23YkeePui4
And I miss my blue tick !
Another great example of UHI (Urban Heat Island) with tomorrow's forecast across the #GTA
Mid 30s across most of Southern #Ontario with upper 30s/ near 40C across the "concrete jungle" (#Toronto)/ #GTHA#OnWX#ONStorm