Climate 'Science' Laugh of the Week
A colleague passed along a criticism of this article and he has a point. I was not clear. I am criticizing the New Science article, not the paper itself. Specifically, this language:
It's worse than we thought. Scientists may have hugely underestimated the extent of global warming because temperature readings from southern hemisphere seas were inaccurate.
Comparisons of direct measurements with satellite data and climate models suggest that the oceans of the southern hemisphere have been sucking up more than twice as much of the heat trapped by our excess greenhouse gases than previously calculated. This means we may have underestimated the extent to which our world has been warming.
It is written present tense for a study that ended in 2003 which isn't mentioned until the end of article (i.e., a reader would be misled unless they read well into the article). The article is nonsense. That said, I apologize for the confusion as to where my criticism was directed.
Original Posting:
The study covers the period from 1970 to 2003. Cai says that, during that time, while the northern hemisphere has been well sampled by cargo ships and projects led by wealthy countries north of the equator, very few direct measurements have been taken in the south. So it's not surprising that the in-situ measurements have been wrong. "But this is huge," says Cai.
Ah, it is late 2014.
The study cherry-picked a period that omitted the cool temperatures before the and the lack of warming after (below).
In your post, you refers to the New Scientist post here:
ReplyDeletehttp://www.newscientist.com/article/dn26317-the-world-is-warming-faster-than-we-thought.html
You seem to critique the article and the study referred to for not using the Argos data, as well as for the time period under study. In the New Scientist article, the use of newer Argos data is mentioned at the end:
"Since around 2000, a network of buoys called the Argo floats have been collecting more accurate global ocean data, so more recent measurements of the southern hemisphere are more reliable."
Furthermore, if you read the paper by Durack referred to in the New Scientist article, there is a different message.
Journal reference: Nature Climate Change, DOI: 10.1038/NCLIMATE2389
The study looks at potential underestimation of ocean heat uptake in the southern hemisphere before Argos measurements, pre-2004. The authors compare altimeter measurements, in situ measurements and CMIP5 hindcasts to conclude that in situ measurements of SST in the southern hemisphere during this period may have significantly underestimated ocean heat content in the southern hemisphere in the pre-Argos era. They mention in the first paragraph,
"Recent estimates of OHC (Ocean Heat Content) change attempt to address sampling deficiencies by relying on coincident sea surface height (SSH) estimates or the modern Argos array."
The authors of the Nature Climate Change article specifically were analyzing the period before the Argos data became available and state,
"We analyse the 35-year period (1970-2004) over which both the CMIP5 'historical' data are available and during which observational deficiencies are small enough to yeild reliable OHC chnages, at least in the Northern Hemisphere."
Later in the paper, the authors state
"This shift in the observed OHC trend is consistent with increasing influence of Argo data after 2004, at which point in-situ measurements begin to provide near-global coverage."
Careful reading of the paper cited should, therefore, explain the time period studied as a well defined climatological period with accompanying CMIP5 data sets as well as the need to reevaluate pre-Argo OHC and SST measurements. Secondarily, both the New Scientist article and the Nature Climate Change paper acknowledge that the Argo data set gives a better estimate of SST, especially in the Southern Hemisphere.
Thank you for the comment and it is possible I have misconstrued the thrust of the paper. However, it is nonsensical to claim that "warming" (present tense) is "worse than we thought" for a paper with a data period that ended 11 years ago.
ReplyDeleteTo be fair to all concerned, I am going to review the paper itself and I have invited additional commentary. Stay tuned.