2024 Mauna Loa CO2 levels

[Renerpho]

I won't bother asking this time.

Well, I actually did, and I received a quick reply this time:

I got this email from Xin Lan at NOAA today. This applies to the CH4, N2O and SF6 monthly means.

Dear Daniel,
We have encountered an issue with our calculation of the global means this month. We are still working to sort it out. An update will be done at least by Oct 5th, and possibly sooner.
Best,
Xin (Lindsay)

[Stephan]

The latest Mauna Loa CO₂ weekly average has been published:

Week beginning on September 15, 2024:     421.98 ppm
Weekly value from 1 year ago:                    418.33 ppm
Weekly value from 10 years ago:                 395.24 ppm
Last updated: September 22, 2024

The annual increase sits at 3.65 ppm, which is obviously above the 10 y average of 2.67 ppm/a which itself is ridiculously high. The intra-day variation remained very high, but the daily averages were really smooth. There is no tendency to slip down into the seasonal minimum, so it can be stated that there was no significant change since mid August.

[Renerpho]

The seasonal minimum is usually "flat and broad", and it looks like we may be seeing the same thing this year -- albeit at a level that's far beyond the MetOffice forecast made in January.

In 2023, CO₂ levels reached their minimum in mid-September, and started rising again around October 10th.

The weekly average of 421.98 ppm corresponds to an increase of 3.65 ppm over the previous year (418.33 ppm). The average for the week starting 22 September 2023 was 418.28 ppm, followed by 418.35 ppm for the week starting September 29th. Unless we see a significant drop, or an extremely late seasonal minimum, we can expect the annual rise to remain stable (near 3.5-4.0 ppm) for the next couple of weeks.

[Stephan]

Another weekend is almost over - time to deliver the latest Mauna Loa CO₂ weekly average.

Week beginning on September 22, 2024:     421.71 ppm
Weekly value from 1 year ago:                    418.28 ppm
Weekly value from 10 years ago:                 395.47 ppm
Last updated: September 29, 2024

The annual increase is at 3.43 ppm, higher than usual.
But...most of the last days were "unavailable". The intra-day variations were higher than the limits NOAA set up for its evaluation. Nevertheless, on the hourly/daily graph site two daily average values were noted, although these days were also flagged with "unavailable".
Therefore this weekly average must be taken with some caution.

[Renerpho]

Nevertheless, on the hourly/daily graph site two daily average values were noted, although these days were also flagged with "unavailable".

For the (lack of) meaning of the "unavailable" tag, see here.

The hourly values in NOAA's chart (attached below) don't look so bad. I think there's a chance that the missing daily values will be added during reanalysis a few months from now, similar to what happened with the data for February-April 2024.

Outlook: The week starting September 29th had an average of 418.35 ppm in 2023. We can therefore probably expect annual rises near 3.5 ppm for the next couple of weeks (compare here).

[Stephan]

NOAA has published another monthly average of Mauna Loa CO₂.

September 2024:       422.03 ppm
September 2023:       418.51 ppm
September 2014:       395.38 ppm
Last updated: Oct 05, 2024

The annual increase for September 2024 is at 3.52 ppm/a. The increase rate is much higher than the 10 y average of 2.67 ppm/a and the expected rate which should be (linearly fitted 1958-2024) at 2.59 ppm/a.

I set an index of 100 [338.75 ppm] for 1980. September 2024 is at 124.6 compared to that index.

[Stephan]

A new weekly Mauna Loa CO₂ average has been published:

Week beginning on September 29, 2024:     421.95 ppm
Weekly value from 1 year ago:                    418.35 ppm
Weekly value from 10 years ago:                 395.61 ppm
Last updated: October 06, 2024

The pattern (high intra-day variability but almost no inter-day changes) remains as it was the last weeks. Some days were "unavailable". The seasonal minimum should now be over, but a distinct week "when was it exactly?" cannot be defined, the values haven't changed significantly since 2^nd week of August.
The annual increase is at 3.60 ppm/a, a candidate for the top twenty list, and of course higher than the 10 y average of 2.63 ppm/a.

Therefore the annual increase on a monthly basis (see my posting above) is also very high.

[Renerpho]

a candidate for the top twenty list

It is in 82nd place (out of 2,541). The times when a 3.6 ppm rise was a candidate for the top 20 are, sadly, long over. A 4.2 ppm rise barely makes it into the top 20 nowadays (see list below).

If the year ended today, the yearly average would be 3.55 ppm higher than for the same period in 2023. That would (and probably will) absolutely shatter the old record.

Outlook
The week starting 6 October 2023 had an average of 418.48 ppm, similar to the week before. If the flat trend of the previous weeks continues then we should see another increase near 3.5 ppm next week. Business as usual for 2024...
The week after that should be different. There was a brief peak at that time in 2023, leading to a higher weekly average of 419.56 ppm. Unless we see a similar peak this year, there should be a brief pause (of one week) in the extremely high increases.
After that, we will have three more weeks with potential for annual increases near 4 ppm.

List of highest weekly increases
  #1: 5.73 ppm, 2024-02-04
  #2: 5.57 ppm, 2024-03-10
  #3: 5.48 ppm, 2024-02-18
  #4: 5.07 ppm, 2016-07-31
  #5: 4.81 ppm, 2016-06-12
  #6: 4.56 ppm, 2016-04-10
  #7: 4.53 ppm, 2024-03-17
  #8: 4.53 ppm, 2016-05-22
  #9: 4.51 ppm, 2019-04-28
#10: 4.50 ppm, 2024-07-14
#11: 4.40 ppm, 2012-05-06
#12: 4.34 ppm, 2014-04-13
#13: 4.33 ppm, 2016-01-31
#14: 4.29 ppm, 2020-03-22
#15: 4.26 ppm, 1998-07-19
#16: 4.25 ppm, 2016-04-24
#17: 4.24 ppm, 2016-04-17
#18: 4.24 ppm, 2010-04-18
#19: 4.23 ppm, 2024-03-31
#20: 4.19 ppm, 2016-03-20

[gerontocrat]

& here is the graph for Mauna Loa + a graph for global CO2

click images to enlarge

[Stephan]

Thank you - as always - for the graphs

[Stephan]

Sunday afternoon - time to post the latest Mauna Loa CO₂ weekly average.

Week beginning on October 06, 2024:     422.16 ppm
Weekly value from 1 year ago:                418.47 ppm
Weekly value from 10 years ago:            395.73 ppm
Last updated: October 13, 2024

The annual increase is at 3.69 ppm/a, again much above the 10 y average of 2.64 ppm/a.
Last week again showed large intra-day variation (three days were "unavailable"), but relatively constant daily averages - which still haven't changed significantly since second week of August and which make the minimum almost flat for two months.

[Renerpho]

Stephan said it all. This week more or less went down as expected.

As mentioned in my latest post, there was a small bump in CO₂ levels during the week starting 13 October 2023, with an average of 419.56 ppm. If we remain at current levels (or follow the slow increase we're in after the seasonal minimum), we should see an increase near 2.5 ppm. And then back to 3.5-4 ppm for the weeks after this...

By the way, I'm ready to call that we had an early minimum - some time in the second half of September. between the 2021 and 2023 dates. Not quite as flat as the 2020 minimum, but not as pronounced as we saw in, for example 2022. Roughly average, I'd say, if not a bit early.

[Stephan]

Sunday afternoon - time for an update on Mauna Loa CO₂.

Week beginning on October 13, 2024:     422.45 ppm
Weekly value from 1 year ago:                419.56 ppm
Weekly value from 10 years ago:             395.86 ppm
Last updated: October 20, 2024

As expected, this week's increase rate is lower than the previous ones due to a slightly higher value in 2023. Nevertheless, with 2.89 ppm/a it is still higher than the 10 y average of 2.66 ppm/a.
The data themselves still show high inter-day, but low intra-day variability. So far no changes since 2^nd week of August.

[Renerpho]

There was a problem with some of the data last week, specifically with an anomalously low daily average on October 16th, and I waited for that to be corrected. NOAA has done so today, so here is my delayed post:

The weekly average was 422.62 ppm (corrected from the originally published 422.45 ppm), up 3.06 ppm from last year. That's roughly on track with how the season is expected to progress.

If the year ended today, the annual rise would be 3.54 ppm -- well above the previous record. We are at the point now where we would break the old record even if CO₂ levels "flatlined" from here (meaning the expected seasonal increase stops and we stay near 422.5 ppm for the rest of the year). There's just not enough time left to bring the average down. In other words, we are practically guaranteed a record-high increase. We are also about six weeks ahead of the Met Office forecast...

Outlook: More of the same for the coming three weeks. Then there's a spike in last year's CO₂ levels, which may lead increases to briefly drop to around 1-2 ppm.

[Stephan]

A new NOAA Mauna Loa weekly CO₂ average is available.

Week beginning on October 20, 2024:     422.17 ppm
Weekly value from 1 year ago:                418.92 ppm
Weekly value from 10 years ago:             396.21 ppm
Last updated: October 27, 2024

We are still in a very long and flat seasonal minimum. On some days the intra-day flucutation was much smaller than in the last month. Nevertheless, in this week there were again some "unavailable" days.
The annual increase is at 3.25 ppm/a, which is again higher than the 10 y average of 2.60 ppm/a.

[Renerpho]

A bit of an uptick during the 2nd half of the week, on top of what's now a clear seasonal upward trend, leading to a weekly average of 423.15 ppm (last year: 418.90 ppm). The annual increase of 4.25 ppm is at #16 in the list of highest ever increases (out of a total of 2,633 weeks). 7 of the top 20 weeks have happened this year.

List of largest annual increases
  #1: 5.73 ppm, 2024-02-04
  #2: 5.57 ppm, 2024-03-10
  #3: 5.48 ppm, 2024-02-18
  #4: 5.07 ppm, 2016-07-31
  #5: 4.81 ppm, 2016-06-12
  #6: 4.56 ppm, 2016-04-10
  #7: 4.53 ppm, 2024-03-17
  #8: 4.53 ppm, 2016-05-22
  #9: 4.51 ppm, 2019-04-28
#10: 4.50 ppm, 2024-07-14
#11: 4.40 ppm, 2012-05-06
#12: 4.34 ppm, 2014-04-13
#13: 4.33 ppm, 2016-01-31
#14: 4.29 ppm, 2020-03-22
#15: 4.26 ppm, 1998-07-19
#16: 4.25 ppm, 2024-10-27
#17: 4.25 ppm, 2016-04-24
#18: 4.24 ppm, 2016-04-17
#19: 4.24 ppm, 2010-04-18
#20: 4.23 ppm, 2024-03-31

[Stephan]

In addition to renerpho's posting (thank you) here is my evaluation of the latest CO₂ weekly average.

Week beginning on October 27, 2024:     423.15 ppm
Weekly value from 1 year ago:                418.90 ppm
Weekly value from 10 years ago:            397.57 ppm
Last updated: November 03, 2024

Finally this week has left the long (11 weeks) period of weekly averages of 422 ± 1 ppm. The annual increase is at 4.25 ppm/a, which is 66% higher than the 10 y average of 2.56 ppm/a.
In contrast to many weeks before the intra-day variability was exceptionally low.

[Stephan]

NOAA has published another monthly average of Mauna Loa CO₂.

October 2024:       422.38 ppm
October 2023:       418.82 ppm
October 2014:       396.03 ppm
Last updated: Nov 05, 2024

The annual increase for October 2024 is at 3.56 ppm/a. The increase rate is much higher than the 10 y average of 2.64 ppm/a and the expected rate which should be (linearly fitted 1958-2024) at 2.60 ppm/a.

I set an index of 100 [338.75 ppm] for 1980. October 2024 is at 124.7 compared to that index.

[gerontocrat]

& the graphs for Mauna Loa & Global CO2 ppm

click images to enlarge

[Stephan]

Thank you - as always - for the graphs, dear Gero.

[Stephan]

Another week has passed - here is the latest Mauna Loa CO₂ weekly average.

Week beginning on November 03, 2024:     423.34 ppm
Weekly value from 1 year ago:                   419.38 ppm
Weekly value from 10 years ago:                396.91 ppm
Last updated: November 10, 2024

The annual increase is back at almost 4 ppm (3.96 ppm/a), which is obviously higher than the 10 y average of 2.64 ppm/a. Like last week the daily values were pretty stable. Only Nov 3 and 4 had large intra-day fluctuations.

[Renerpho]

Although it wasn't unexpected, the increase of 3.96 ppm was again very high this week.

The good news is that we'll likely see a much lower increase next week, and probably also the week after that (see charts below). The bad news is that that's just because there was a "bump" at that time in 2023. We may then return straight to increases near 4 ppm. Weekly averages for the coming weeks in 2023 were:

3-9 November: 419.38 ppm
10-16 November: 421.00 ppm
17-23 November: 421.40 ppm
24-30 November: 420.32 ppm
1-7 December: No data*
8-14 December: 421.93 ppm

* Only a single daily average, which was 420.74 ppm. Pending any updates, NOAA may or may not use that as the weekly average.

[Stephan]

As renerpho had already expected, this week Mauna Loa CO₂ is at a much lower increase rate than the last weeks.

Week beginning on November 10, 2024:     423.60 ppm
Weekly value from 1 year ago:                   421.00 ppm
Weekly value from 10 years ago:                397.33 ppm
Last updated: November 17, 2024

The reason for this is a jump in the 2023 value of this week, therefore the actual increase rate of 2.60 ppm/a is close to the 10 y average of 2.63 ppm/a.
The data was very smooth, both intra- as well as inter-day variations kept very small.

[Renerpho]

Just a few charts; see Stephan's post for the numbers.

Next week had a weekly average of 421.40 ppm in 2023, so there's a chance that we briefly drop to an annual increase below 2.5 ppm. We'll see, as we are entering the time of the year where "jumps" (like the ones in 2020, 2022 and 2023) become more likely.

[Renerpho]

The average for the week beginning on 17 November 2024 was 423.96 ppm, which was 2.56 ppm higher than last year (421.40 ppm), and slightly higher than I had expected; compare previous posts.

This was the last opportunity this year for the increase rate to drop well below 2.5 ppm. Next week's average will be compared to 420.32 ppm from the year before. If we follow the seasonal trend then we'll see an increase in the 3.5-4 ppm range. However, there's always the chance for an outlier at this time of the year (depending on the weather at Mauna Loa), in either direction...

[Stephan]

Please find attached the latest weekly average on Mauna Loa CO₂.

Week beginning on November 17, 2024:     423.96 ppm
Weekly value from 1 year ago:                   421.40 ppm
Weekly value from 10 years ago:                397.47 ppm
Last updated: November 24, 2024

The annual increase of 2.56 ppm/a is close to the 10 y average of 2.65 ppm/a. The data were once again very stable with only minor intra- and inter-day variability.
For the expected further development of the increase rate see renerpho's posting above.

[Renerpho]

The weekly average for the week beginning 24 November 2024 was 424.59 ppm, an increase of 4.28 ppm over last year's value of 420.31 ppm.

It is the 15th largest increase since records began in 1978 (out of a total of 2,637 weeks). It is also somewhat higher than expected from the seasonal trend, compare the previous posts, even though variability has been relatively low this week; and much higher than the long-term trend of 2.59 ppm/year.

There is a near-100% chance that the annual growth rate with surpass the record set in 2023 (3.36 ppm), which itself had shattered the previous record (3.03 ppm, set in 2016). We are on track to an annual growth rate in the 3.55-3.6 ppm range. https://gml.noaa.gov/ccgg/trends/gr.html

List of largest annual increases
  #1: 5.73 ppm, 2024-02-04
  #2: 5.57 ppm, 2024-03-10
  #3: 5.48 ppm, 2024-02-18
  #4: 5.07 ppm, 2016-07-31
  #5: 4.81 ppm, 2016-06-12
  #6: 4.56 ppm, 2016-04-10
  #7: 4.53 ppm, 2024-03-17
  #8: 4.53 ppm, 2016-05-22
  #9: 4.51 ppm, 2019-04-28
#10: 4.50 ppm, 2024-07-14
#11: 4.40 ppm, 2012-05-06
#12: 4.34 ppm, 2014-04-13
#13: 4.33 ppm, 2016-01-31
#14: 4.29 ppm, 2020-03-22
#15: 4.28 ppm, 2024-11-24
#16: 4.26 ppm, 1998-07-19
#17: 4.25 ppm, 2024-10-27
#18: 4.25 ppm, 2016-04-24
#19: 4.24 ppm, 2016-04-17
#20: 4.24 ppm, 2010-04-18

[Stephan]

renerpho has already said it all, so here is the weekly Mauna Loa CO₂ average in my format:

Week beginning on November 24, 2024:     424.59 ppm
Weekly value from 1 year ago:                   420.31 ppm
Weekly value from 10 years ago:                397.98 ppm
Last updated: December 01, 2024

The intra-day variations became larger this week, and the values now increase from day to day, leaving the seasonal minimum behind and heading towards the seasonal maximum in (probably) May.

[kassy]

There is a near-100% chance that the annual growth rate with surpass the record set in 2023 (3.36 ppm), which itself had shattered the previous record (3.03 ppm, set in 2016). We are on track to an annual growth rate in the 3.55-3.6 ppm range.

Makes you wonder about next year already. We ran out of carbon budget slightly earlier then projected but the projections probably missed a lot of sink destruction.

[Stephan]

NOAA has published another monthly average of Mauna Loa CO₂.

November 2024:       423.85 ppm
November 2023:       420.46 ppm
November 2014:       397.28 ppm
Last updated: Dec 05, 2024

The annual increase for November 2024 is at 3.39 ppm/a. The increase rate is much higher than the 10 y average of 2.66 ppm/a and the expected rate which should be (linearly fitted 1958-2024) at 2.60 ppm/a.

I set an index of 100 [338.75 ppm] for 1980. November 2024 is at 125.1 compared to that index.

[bosbas]

Compared to Nov 2022, CO2 shows an increase of 6.38 ; should we get used to such large increases continuing?

[kassy]

Since output did not grow that much this probably hints declining sinks and that should persist until it gets worse.

[gerontocrat]

& here is the graph (also for Global CO2)

Note that Mauna Loa CO2 ppm in October 2024 is higher than the linear trend projection in 2030; so looking at the trend lines one gets the distinct impression that the linear trend is becoming untenable.

10 years or a bit less to CO2 at 450ppm? (My faulty memory remembers 450 ppm regarded by the IPCC as a danger point - pass at your peril?)

[Renerpho]

Compared to Nov 2022, CO2 shows an increase of 6.38 ; should we get used to such large increases continuing?

Increases in late 2022 and early 2023 were unusually low, which makes the increases now look particularly large in comparison. We can expect this to continue for a few more months, but we'll eventually get to the point where we compare current levels to the unusually high numbers we've seen since April 2023. I would not be surprised if that "2-year increase" drops below 5 ppm in the next six months.

We should get used to seeing increases around 3 ppm/year, and above 2 ppm/year even during La Niña years. Anything larger than that is still an anomaly, for now.

(Of course the goal is to get that rate to below 0 within the not too distant future.)

[kiwichick16]

450 ppm .....50% chance of "catastrophic climate change  "

https://www.theguardian.com/environment/2006/oct/18/bookextracts.books

[Stephan]

A new Mauna Loa weekly CO₂ average is available.

Week beginning on December 01, 2024:     424.95 ppm
Weekly value from 1 year ago:                   420.74 ppm
Weekly value from 10 years ago:               398.77 ppm
Last updated: December 08, 2024

The annual increase is at 4.21 ppm/a which is in the top 30 list renerpho published last week in this thread.
The intra-day fluctuations grow further, one day was "unavailable". We are on the way into the seasonal maximum next spring.

[bosbas]

Seems like they used the only available day from last year as the weekly average (420.74)

[Renerpho]

A few weeks ago, I noted that data during the week 1-7 December 2023 was of particularly bad quality:

1-7 December: No data*
8-14 December: 421.93 ppm

* Only a single daily average, which was 420.74 ppm. Pending any updates, NOAA may or may not use that as the weekly average.

This does, of course, not mean that the weekly average of 424.95 ppm this week wasn't very large, but the increase of 4.21 ppm/year stands on shaky grounds. Nonetheless, it apparently meets NOAA's requirements, and its place at #22 in the all time list is not undeserved.

Last year, the data quality got better after this. There was a "bump" up to 421.93 ppm the following week. If we follow the seasonal trend, the next annual increase should be about 3-3.5 ppm. The weeks after that, we had:

15-21 December 2023: 422.40 ppm
22-28 December 2023: 421.75 ppm
29 December 2023-4 January 2024: 422.31 ppm

One more thing: We are now eight months past the end of the last El Niño. That's exactly the average delay it takes for ENSO's effects to become visible in Mauna Loa CO₂ numbers. We may see a notable dip because of it, by something like 0.3-0.5 ppm. Something to watch out for over the next few months.

[Renerpho]

The week beginning on December 8, 2024 came in at 425.67 ppm, 3.74 ppm higher than last year's value of 421.93 ppm.

Variability was moderate, with the exception of a small "bump" to near 428 ppm on December 11th, which lasted just a single day. All seven days this week had good data.

[Renerpho]

In both 2022/23 and 2023/24, there was hardly any seasonal increase in CO₂ levels between mid December and late January. Will we see a repeat of that? If we instead continue to follow the seasonal trend shown below (like most years do), we may end up with some surprisingly big annual increases over the next few weeks.

[Stephan]

Sunday evening is time for a new Mauna Loa CO₂ average.

Week beginning on December 15, 2024:     424.96 ppm
Weekly value from 1 year ago:                  422.40 ppm
Weekly value from 10 years ago:               399.32 ppm
Last updated: December 22, 2024

The annual increase is back down at 2.56 ppm/a. It is at the 10 y average of 2.56 ppm/a. The intra-day variations remained large, two days were "unavailable".

[Stephan]

The last full 2024 week has passed - here is the last weekly average:

Week beginning on December 22, 2024:     425.59 ppm
Weekly value from 1 year ago:                   421.75 ppm
Weekly value from 10 years ago:               399.08 ppm
Last updated: December 29, 2024

The annual increase is at 3.84 ppm which is much higher than the 10 y average of 2.65 ppm/a.
The intra-day variations were very small, apart from Dec 28.