There is a weblog called “Skeptical Science – Getting Skeptical About Global Warming Skepticism” that has a misleading post on ocean heat content titled
Ocean cooling: skeptic arguments drowned by data
The post starts with
In 2008, climate change sceptic Roger Pielke Sr said this: “Global warming, as diagnosed by upper ocean heat content has not been occurring since 2004”. It is a fine example of denialist spin, making several extraordinary leaps:
•that one symptom is indicative of the state of an entire malaise (e.g. not being short of breath one day means your lung cancer is cured).
•that one can claim significance about a four year period when it’s too short to draw any kind of conclusion
•that global warming has not been occurring on the basis of ocean temperatures aloneSo much for the hype. What does the science say about the temperature of the oceans – which, after all, constitute about 70% of the Earth’s surface? The oceans store approximately 80% of all the energy in the Earth’s climate, so ocean temperatures are a key indicator for global warming.
No straight lines
Claims that the ocean has been cooling are correct. Claims that global warming has stopped are not. It is an illogical position: the climate is subject to a lot of natural variability, so the premise that changes should be ‘monotonic’ – temperatures rising in straight lines – ignores the fact that nature doesn’t work like that. This is why scientists normally discuss trends – 30 years or more – so that short term fluctuations can be seen as part of a greater pattern. (Other well-known cyclic phenomena like El Nino and La Nina play a part in these complex interactions).
The post starts by mislabeling me as a “climate change sceptic” and a “denialist”. Not only is this completely incorrect (as can be easily confirmed by reading our article
Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell, W. Rossow, J. Schaake, J. Smith, S. Sorooshian, and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union),
but it sets the tone of their post as an ad hominem attack, rather than a discussion of the issue.
The author of this post documents in the figures that they present, that upper ocean heat, in terms of its annual average, did not accumulate during the period ~2004 through 2009. This means that global warming halted on this time period. There is no other way to spin this data.
The claim in the post (apparently written by Graham Wayne) Does ocean cooling prove global warming has ended? that
“The most recent ocean measurements show consistent warming”
is false (unless the author of this post has new data since 2009 which may show warming). The recent lack of warming (the data do not support a cooling, despite what the Skeptical Science weblog reports) does not prove or disprove whether global warming over a longer term has ended.
However, the ocean heat content provides the most appropriate metric to diagnosis global warming in recent (since ~2004 when the Argo network became sufficiently dense) and upcoming years, as recommended, of example, in
Pielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55.
The author of the post on Skeptical Science continues to present misinformation in their Intermediate level post where it is stated
“Early estimates of ocean heat from the Argo showed a cooling bias due to pressure sensor issues. Recent estimates of ocean heat that take this bias into account show continued warming of the upper ocean. This is confirmed by independent estimates of ocean heat as well as more comprehensive measurements of ocean heat down to 2000 metres deep.”
This is an erroneous statement. There was not continued warming for the time period 2004 to 2009, as confirmed by Josh Willis in
Pielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55.
Recently, Josh Willis reported that an updated analysis will be available this Fall.
What the Skeptical Science fails to recognize is that with respect to the diagnosis of global warming using Joules of heat accumulation in the oceans, snapshots of heat content at different times are all that is needed. There is no time lag in heating or cooling. The Joules are either there or they are not. The assessment of a long-term linear trend is not needed.
For example, if the ocean lost its heat in one or two years (such as from a major volcanic eruption), the global warming “clock” would be reset. The Skeptical Science statements that
“Claims that the ocean has been cooling are correct. Claims that global warming has stopped are not.”
illustrates their lack of understanding of the physics. If ocean cooling does occur, it DOES mean global warming as stopped during that time period.
What would be useful is for the weblog Skeptical Science authors to discuss the value of using (and issues with using) the accumulation of Joules in the climate system as the primary metric to monitor global warming.
Climate Science: Roger Pielke Sr. 