by Judith Curry
I’m bowing to pressure to prepare a post on a current science topic that people seem to want to talk about. This topic refers to Kevin Trenberth’s infamous statement in the CRU emails:
The fact is that we can’t account for the lack of warming at the moment and it is a travesty that we can’t.
This statement was written in reference to the following paper: An imperative for climate change planning: tracking Earth’s global energy (Trenberth 2009). The paper discusses the planet’s energy budget in terms of how much net energy is flowing into our climate and where it’s going, and how we observe and track this energy flow. For additional background on this, see also Trenberth, Fasullo and Kiehl.
Trenberth and Fasullo wrote a follow on perspective published in Science entitled “Tracking earth’s energy: from El Nino to Global warming.” The punchline of the paper is there is observational evidence for missing energy accumulating in the climate system for the last 10 years.
Roy Spencer responded to Trenberth and Fasullo here and here, There is a back and forth exchange between Trenberth and Pielke Sr here. The gist of their arguments relate to problems in the measurements and the possible impact of clouds.
This week, there is discussion about a new paper by Knox and Douglass entitled “Recent Energy Balance of Earth” is in press at the International Journal of Geosciences and some text is posted at WUWT, with the following overall punchline: they find that estimates of the recent (2003–2008) ocean heat content rates of change (observed from ARGO floats) are preponderantly negative, which does not support the existence of either a large positive radiative imbalance or a “missing energy.”
Let me know if you spotted any other interesting discussions of this issue.
JC’s comments: I haven’t been following this too closely or reading all the papers in any details, but here goes. Measuring the Earth’s radiation balance (and changes thereof) is very difficult. Nevertheless, there is the expectation that if we keep dumping more greenhouse gases into the atmosphere, we should see surface temperatures warm, with some allowances for this warming to be masked for short periods of time by natural climate variability. Assuming that the Knox and Douglass analysis holds up, it appears that there is no storage of the heat below the ocean surface. The other choice seems to be a redistribution of clouds that has changed the earth’s radiation balance (Roy Spencer has written on this topic at length). If a climate shift has indeed occured ca 2001/2002 (see the climate shift thread), then the associated circulation changes would not surprisingly be associated with a change in global cloud amount or a redistribution of clouds.