Missing Heat Hides From Climate Scientists
Climate scientists have decided that as much as half of the heat energy, believed to have built up on Earth in recent years, is hiding somewhere it can not be found. By measuring the radiative energy input at the top of Earth's atmosphere, scientists have a pretty good idea of how much energy is entering the planetary environment—the problem is figuring out where it goes. The most likely place is in the deep ocean, whose waters form a huge potential storage place for heat. Because energy is exchanged between the atmosphere and the ocean, this heat can resurface at a later time to affect weather and climate on a global scale. It has been suggest that last year’s rapidly occurring El Niño may be one way the “missing” solar energy has reappeared—the implication being more sudden El Niño events may be on the way.
Oceans contain around 80% of the climate system's total energy, so ocean heat is a good measure of what is happening with Earth's climate. According to a Perspectives article in the April 16, 2010, issue of Science, “Tracking Earth's Energy,” science has been unable to to properly track energy within Earth's environmental system. Kevin E. Trenberth and John T. Fasullo , both scientists at the National Center for Atmospheric Research (NCAR), warn in the new study that satellite sensors, ocean floats, and other instruments are inadequate to track this “missing” heat. They fear that it may be building up in the deep oceans or elsewhere in the climate system. “The heat will come back to haunt us sooner or later,” says Trenberth, the lead author. “The reprieve we’ve had from warming temperatures in the last few years will not continue. It is critical to track the build-up of energy in our climate system so we can understand what is happening and predict our future climate.”
As noted on the NCAR site, a Science Perspectives piece is not formally peer-reviewed, but is reviewed by editors of the journal. Science reportedly invited Trenberth to submit the article after an editor heard him discuss the research at a scientific conference. Trenberth and his co-author, Fasullo, focused on what they call a central mystery of climate change. Why, since 2003, have scientists been unable to determine where much heat energy Earth receives from the Sun is going. According to the NCAR site:
Satellite measurements indicate that the amount of greenhouse-trapped solar energy has risen over recent years while the increase in heat measured in the top 3,000 feet of the ocean has stalled. Although it is difficult to quantify the amount of solar energy with precision, Trenberth and Fasullo estimate that, based on satellite data, the amount of energy build-up appears to be about 1.0 watts per square meter or higher, while ocean instruments indicate a build-up of about 0.5 watts per square meter. That means about half the total amount of heat is unaccounted for.
Either the satellite observations are incorrect, says Trenberth, or large amounts of heat are penetrating to regions on Earth that are not adequately measured. One such place is the deepest parts of the oceans. Compounding the problem, Earth’s surface temperatures have largely leveled off in recent years. This inability to properly track energy has implications for understanding the way climate works and most definitely on predicting future climate. Obviously, if scientists are at a loss to identify the hiding place of the missing heat climate modelers are unable to include its possible future effects in their programs. With as much as half of the suspected heat energy buildup gone missing, it must be asked how well science understands Earth's climate.
Where does the energy go?
El Niño, periodic events in which the upper ocean waters across much of the tropical Pacific Ocean become significantly warmer, are seen by many as a mechanism for dumping heat, stored in the ocean, back into space. Trenberth and Fasullo explain the relationship between the ENSO, the El Niño Southern Oscillation, and delayed release of ocean stored energy this way:
To understand how energy is taken up and later released by the climate system, consider the natural variability from El Niño Southern Oscillation. The cold sea surface temperatures in the equatorial Pacific present in normal or La Niña conditions create conditions favorable for fewer clouds and more sunshine and a build-up of heat in the ocean as a precursor of El Niño. The spread of warm waters across the Pacific, together with changing winds, in turn promotes evaporative cooling of the ocean, moistening the atmosphere and fueling tropical storms and convection over and around the anomalously warm waters. The changed atmospheric heating alters the jet streams and storm tracks and controls weather patterns for the duration of the El Niño event. The loss of heat can in turn lead to La Niña.
A strong La Niña event in 2007–2008 extended into the 2008–2009 northern winter, causing cooler than normal weather across much of the Northern Hemisphere. By June 2009, the situation had reversed as the next, comparatively moderate El Niño emerged. Multiple storms barreled into Southern California in January 2010, consistent with expectations from the El Niño. These storms also caused significant snowfall and precipitation across the American Southwest, South and up the Eastern Seaboard.
There seems to be a lot of confusion regarding ocean temperatures these days. Recently, new estimates of the past temperatures have been published. On in particular, that shows a sudden jump in the 2002-2003 time, prompted Real Climate to post a plot of ocean heat content. This is a contradiction of a 2009 paper by Craig Loehle in Energy & Environment that found global ocean cooling since 2003. The linear component of the model used showed a trend of -0.35 (±0.2) x 1022 Joules per year, shown in the plot below.
The Loehle study showed an unambiguous cooling trend.
“The model, fit to the smoothed data, gave an excellent fit (r = 0.922, R2 = 0.85) and showed clearly that there is an annual periodicity in the data, probably due to the north-south asymmetry in ocean area and the effect of orbital variations over the year,” the study states. The Loehle study was based on ocean heat content anomaly (OHCA) data compiled by Josh Willis et al. Indeed, it was the 2008 paper “Assessing the Globally Averaged Sea Level Budget on Seasonal and Interannual Time Scales,” by Willis, Chambers and Nerem, that prompted this comment by Roger Pielke Sr.:
Global warming, as diagnosed by upper ocean heat content has not been occurring since 2004. It is impossible to know if this lack of warming will continue but these observations are inconsistent with the predictions of long-term global climate predictions, such as reported in the 2007 IPCC report.
Since then, the debate over ocean heat and ocean levels has raged. Claims and counter claims, studies finding warming and studies finding cooling. Now it looks like the warming proponents are throwing in the towel on surface temperature increase (this is the temperature trend, not normal, cyclic variability). In a reply to questions from Dr. Pielke, Dr. Willis said:
There is still a good deal of uncertainty in observational estimates of ocean heat content during the 1990s and into the early part of the 2000s. This is because of known biases in the XBT data set, which are the dominant source of ocean temperature data up until 2003 or 2004. Numerous authors have attempted to correct these biases, but substantial difference remain in the “corrected” data. As a result, the period from 1993 to 2003 still has uncertainties that are probably larger than the natural or anthropogenic signals in ocean heat content that happen over a period of 1 to 3 years. However, the decadal trend of 10 to 15 years seems to be large enough to see despite the uncertainties.
So, despite the confusion caused by changing from XBT (Expendable Bathythermograph) measurements to measurements by the Argos satellite-based location and data collection system, it still looks like the upper portions of the ocean are cooling. Such data discontinuities when changing sensor types or measurement methods is not new, the same type of flap erupted over radiosonde data a decade ago. Even so, the debate about the missing ocean heat is far from over.
The new claim is the missing heat, that climate change supporters so desperately want to find, has gone deep. Dr Pielke has exchanged a series of comments with Dr. Trenberth over his recent paper on the Climate Science website:
Trenberth’s [and co-author, NCAR scientist John Fasullo], however, are grasping for an explanation other than the actual real world implication of the absence of this heat.
Thus, a large amount heat (measured as Joules) does not appear to be stored anywhere; it just is not there.
- First, if the heat was being sequestered deeper in the ocean (lower than about 700m), than we would have seen it transit through the upper ocean where the data coverage has been good since at least 2005. The other reservoirs where heat could be stored are closely monitored as well (e.g. continental ice) as well as being relatively small in comparison with the ocean.
- Second, the melting of glaciers and continental ice can be only a very small component of the heat change (e.g. see Table 1 in Levitus et al 2001 “Anthropogenic warming of Earth’s climate system”. Science).
“I do not agree with your comments. We are well aware that there are well over a dozen estimates of ocean heat content and they are all different yet based on the same data,” said Dr. Trenberth in reply. “There are clearly problems in the analysis phase and I don’t believe any are correct.” Clear admission that climate scientists are groping in the dark here.
“I do not see how such large amounts of heat could have transited to depths below 700m since 2005 without being detected.,” responded Pielke, adding in a conciliatory way: “I am very supportive, however, of your recognition that it is heat in Joules that we should be monitoring as a primary metric to monitor global warming. Our research has shown significant biases in the use of the global average surface temperature for this purpose.”
Research done over the last several years has found that the return currents of the meridional overturning current (MOC) do not behave as previously thought (see “Conveyor Belt Model Broken”). More recently, it has been shown that the great ocean conveyor belt varies in ways unpredicted and previously unsuspected (see “Ocean Conveyor Belt Confounds Climate Science”). During the first 1-year period since new deep sea sensors became operational (measurements from March 2004 through March 2005) the strength of the MOC varied by more than a factor of 8. It still remains unclear how much the meridional overturning circulation varies from year to year, but the old model was clearly wrong.
New sensors reveal unsuspected behavior. Source CSIRO.
Now, the ocean is suspected of harboring hidden heat that scientists claim has gone missing. Some claim the heat is not there, while others, like Trenberth and Fasullo, fear that the missing heat will “come back to haunt us.” One thing is certain—those old claims of “settled science” and a “consensus among the world's scientists” seem to have come back to haunt their originators. The overstatements made by the IPCC and its supporters in the past stand revealed for the empty lies they always were.
Trenberth and Fasullo state that it is imperative to get better measurements of the energy flowing through Earth’s climate system. Improved analysis of energy in the atmosphere and oceans might help researchers better understand and possibly even predict unusual weather patterns, such as the unexpectedly cold weather across much of the United States, Europe, and Asia over the past winter. But for now, no scientist can claim that we truly understand what is going on in Earth's oceans—and that means climate science cannot claim to understand what is going to happen to Earth's climate.
Be safe, enjoy the interglacial and stay skeptical.