There is an interesting post on March 31 2008 of comments by Josh Willis on nationalpost.com by Marni Soupcoff titled “Josh Willis on climate change: Global warming is real” [thanks to Jos de Laat for alerting us to it!].
“As a scientist, I always enjoy it when people outside my field take an interest in oceanography. But I was a bit disappointed to read Lorne Gunter’s column: Perhaps The Climate Change Models are Wrong, March 24.
It is a well-established fact that human activities are heating up the planet and that global temperatures will continue to rise for decades to come. Climate change skeptics often highlight certain scientific results as a means of confusing this issue, and that appears to be the case with Mr. Gunter’s description of our recent results based on data from Argo buoys.
Indeed, Argo data show no warming in the upper ocean over the past four years, but this does not contradict the climate models. In fact, many climate models simulate four to five year periods with no warming in the upper ocean from time to time. The same is true for the warming trend observed by NASA satellites; it too is in good agreement with climate model simulations. But more important than agreement with computer models is the fact that four years with no warming in the upper ocean does not erase the 50 years of warming we’ve seen since ocean temperature measurements became widespread. Nor does it erase the eight inches of sea level rise we’ve experienced in the past 100 years. Both of these are important indicators of human-kind’s effect on the climate.
It is important to remember that climate science is not a public debate carried out on the opinion pages of newspapers. What we know about global warming comes from thousands of scientists pouring over countless data sets, conducting experiments to figure out how the climate works and scrutinizing every aspect of each other’s work.
Scientists don’t determine which results will be picked up by the media and “broadcast far and wide” — reporters do that. New science results often spark new questions (that’s what makes science fun), but they don’t often change the answers to old ones and it’s important to place new results in their proper context. For instance, Mr. Gunter quoted me saying we are in a period of “less rapid warming.” This was not “climate change dogma,” but simply a reminder that other parts of the climate like the atmosphere, sea ice, glaciers and probably the deep ocean– which is not measured by Argo buoys –did continue to heat up even though the upper-ocean didn’t.
It is easy to pick on computer climate models for not simulating certain things or point out the odd measurement that isn’t well understood. Despite this, models and data of all different types tell the same story about the past century: the oceans are warming, sea levels are rising, the temperature of the atmosphere is increasing and carbon dioxide levels continue to go up. Given that, you don’t need a fancy computer model or an Argo buoy to tell you that the future will be warmer.
The real debate is not over whether global warming exists, but how we as a society will address it. The climate system is already committed to a certain amount of warming from carbon dioxide emissions of the past, but the worst effects of global warming can still be avoided. It only requires the will to look toward the future and to curb our addiction to fossil fuels. That’s not alarmist, it’s just common sense.
— Josh Willis is an oceanographer and climate scientist at the Jet Propulsion Laboratory, Pasadena, Calif.”
Josh Willis is a well respected scientist and his view merit consideration. In this case, however, Climate Science concludes that he is misinterpreting the significance of his data analysis. He agrees that
“Indeed, Argo data show no warming in the upper ocean over the past four years”.
He dismisses this though by claiming that
“…but this does not contradict the climate models. In fact, many climate models simulate four to five year periods with no warming in the upper ocean from time to time. “
Where are these model results that show lack of upper ocean warming in recent years? There is an example of a model prediction of upper (3km) ocean heat content for decadal averages in Figure 1 of
Barnett, T.P., D.W. Pierce, and R. Schnur, 2001: Detection of anthropogenic climate change in the world’s oceans. Science, 292, 270-274,
but they did not present shorter time periods. Nonetheless, since Figure 1 is presumably a running 10 year average, the steady monotonic increase in the model prediction of upper ocean heat content (the grey shading) suggests that no several years (or even one year) of zero heating occurred in the model results. The layer they analyzed in the figure is also for the upper 3 km but in Figure 2 the Barnett et al study showed that most of this heating was in the uppermost levels.
Thus the lack of heating in the upper 700m over the last 4 years does conflict with at least the Barnett et al model results!
What the upper ocean data (and lack of warming) actually tells us is that if global warming occurred over the last 4 years, it was in the deeper ocean and is thus not available in the short term to the atmosphere.
Indeed, if it is in the deeper ocean, it likely more diffused and therefore could only enter the atmosphere slowly if at all. This heat could also have exited into space, although the continuation of global ocean sea level rise suggests that this is less likely unless this sea level rise can be otherwise explained.
The other heat stores in the climate system are too small (and the atmosphere has clearly not warmed over the last few years). Global sea ice cover is actually above average at present (the Antarctic sea ice is at a near record level). The continued sea level rise indicates that the heat is in the deeper ocean (which is not predicted by the models).
Josh Willis too easily dismisses the significance of his research findings.