Sweden’s Expressen newspaper is now going to publish daily CO2 levels in the atmosphere

little-known Swedish teenager writes Sweden’s Expressen newspaper are now going to publish daily CO2 levels in the atmosphere “due to climate emergency”!! Very hopeful! Who will be the next to follow? An even less well known English greybeard replies That's gonna be pretty dull. They don't change much day-to-day. A more hopeful colonial inquires Can they take it to hundredths of ppm or something or are there detector limits or noise overwhelming signal problems? And this is a reasonable question.

So: "reporting" on day-to-day global CO2 levels is silly, because they don't change much day to day. Indeed, the annual round of There is more CO2 in the atmosphere today than any point since the evolution of humans is dull too. CO2 is increasing, at about 2.5 ppm per year, but there's a seasonal cycle of about 4 ppm, so there's a peak every year, at which point the "news" that there's a new peak is breathlessly released. And if you were to report, daily, the global average, you'd be reporting declining CO2 levels for maybe a third of the year, which is probably not what the "climate emergency" folk want to see. But can you rescue the interest by reporting the measurements to hundredths of ppm? I don't think so.

Those global measurements are of course made up of lots of little individual measurements and the pretty graph shows how those typically vary by latitude. So, it's kinda like global temperature measurements, which are also going up but which also have a seasonal cycle and spatial variation; and the accuracy of the global average is better than the accuracy of the individual measurements.

Finally, you can look at individual measurements like the Keeling ones at Mauna Loa, and you see how they vary during the day. And you notice that the daily average is very much not the average of the hourly average. If that makes you think "aha! Gotcha you lying scientists can't even do averages properly" then you need to read Dumb America; which will lead you to Eli if you want more detail and How we measure background CO2 levels on Mauna Loa for even more excruciating detail.


How confident are you about confidence intervals? - quiz
* Eli being rather less patient with deniers
* Less wrong isn't necessarily right - TF on How the Rural-Urban Divide Became America’s Political Fault Line by Emily Badger
* A call to climate action - Jonathan T. Overpeck, Cecilia Conde - Science  31 May 2019 / Vol. 364, Issue 6443, pp. 807 / DOI: 10.1126/science.aay1525.
* Can Journalism Be Saved? Nicholas Lemann; New York Review of Books


David B. Benson said...

So little happens in Sweden that might as well.

Victor Venema said...

The Netherlands gave information on air pollution in the daily news. Powerful interests unfortunately managed to stop this again because a daily reminder produced political pressure to act.

Air pollution changes more from day to day, but a daily reminder can be useful.


The pious lede writers of Expressen have hastened to obey the First Commandment of Climateball Communication, recently articulated at Columbia School of Journalism palaver in New York:

Thou shalt not deny a large headline above the fold to any antropogenic climate change news, however tendentious or trivial.

Anonymous said...

I'd quite like to know, on a daily basis, how much CO2 I am breathing in - even in my part of rural Devon it is, I assume, over 400ppm (side question: at what CO2 ppm is 'fresh air' harming me?). The actual number is, however, hard to find, or is daily CO2 conc monitored in the UK somewhere?

Further to that I bought one of those cheap usb powered CO2 monitors. If I plug it into the car's usb port and open the windows I can get a reading of 300-350ppm (by contrast if the monitor is running on the upstairs computer and the gas hob downstairs is on then CO2 conc shoots way above 1000 ppm).

I tentatively conclude that cheap CO2 monitors are as 'accurate' they claim (it does only claim an accuracy of about +-100ppm, maybe, I hope, this one is consistently -100 pm or so...), unless it be the case that there still are places on this planet where you can breath air as little polluted as that, or indeed that outdoor levels of CO2 do vary quite a bit.

crandles said...


displays numbers like
May 31: 414.36 ppm
May 30: 414.40 ppm
May 29: 414.14 ppm
May 28: 414.17 ppm
May 27: 414.82 ppm
That is more stable than many occasions.

Anyway daily can be so noisy, I would suggest next to useless to display daily numbers. Perhaps these (also displayed a tab away) are better:

Week beginning on May 19, 2019: 414.74 ppm
Weekly value from 1 year ago: 411.44 ppm
Weekly value from 10 years ago: 390.53 ppm

But then people might see 3.3ppm a year and in several months when El Nino effect has ended and rate is back down to 2.5ppm a year, do people then think the battle is being won?

>how much CO2 I am breathing in - even in my part of rural Devon
Not daily nor particularly near Devon but some readings for Tacolneston, United Kingdom
available at
Mace Head, County Galway, Ireland is more up to date

In Sweden, the annual cycle can be 25-30 ppm during a year. So very important for them to compare to same day of previous year.

Phil said...

Daytrading spam is OK?

William M. Connolley said...

Gone now.