Saturday, November 09, 2019

Ocean Acidification is Accelerating... the western north Pacific. Not a surprise:
In the Subtropical Frontal zone, we found that the mean rate of acidification tracked the acceleration of the atmospheric CO2 increase; during 2008–2017 the rate of acidification was 30% faster than during 1983–2017.
However, using the monthly Mauna Loa CO2 readings, I find its average from 2008-2017 was 395.5 ppm, while its average from 1983-2017 was 371.6 ppm. An increase of only 6.4%.



Anonymous said...

It's hard to really see the second derivative yet with time series like this. It's one reason why I faulted the "pause" in temp increase that denialists pushed. We are talking about statistical processes and one really has to take some time to see even the first derivative. Making too much hay of isolated ten years is wrong whether done by one side or the other.

David Appell said...

You faulted the pause? You're anonymous, so no one knows what you did. What are you so afraid of?

Ned said...

Oy. The excerpt you quote is a mess (comparing the mean rate of increase in 2008-2017 vs 1983-2017?) but your comparison to Mauna Loa is off ( ... I believe ... ).

The relevant comparison would not be of the mean concentrations, but of the mean rates of increase in concentration during the two (overlapping!) time periods. That is (I think!) what the quote in the paper is referring to for ocean acidification.

In 1983-2017, the mean annual increase in CO2 at Mauna Loa was 1.87 ppm/yr
In 2008-2017, it was 2.25 ppm/yr, an increase of 20% over the full time period.

So, a bit lower than the 30% quoted for OA, but much higher than your 6%.

FWIW, it's not particularly hard to see the acceleration in the CO2 data. The annual increase is increasing at a rate of 0.029 +- 0.0034 ppm/year^2.