Roger Pielke Sr. has a guest post on Watts Up With That (WUWT) called a comment on Kevin Trenberth’s interview on February 17 2014 – an example of misrepresenting climate science. He’s referring to an interview in which the interviewees were Roger Pielke Jr. (his son) and Kevin Trenberth. Apparently Kevin Trenberth said
“You can add up how much of that heat there is and over a six month period it’s equivalent to running a very small microwave over every square foot at full power for about ½ hour”
According to Roger, Public Radio listeners and Mr. Warner were misled by this analog. Why? Because the effect/impact of one microwave oven per square foot running at half power for half an hour, isn’t the same as the effect of enhanced greenhouse gas concentrations in our atmosphere. Sure, that’s true, but Kevin Trenberth didn’t say this. He very specifically referred to the heat/energy. I haven’t actually checked that it is quantitatively correct, but I have no reason to think that it isn’t. I believe that he’s simply trying to illustrate how much energy our climate system is accruing. He’s not trying to suggest that this process is identical and has the same effect as microwave ovens running for half an hour. Surely, noone would actually think he meant that?
It does seem as though there are no suitable – for some at least – analogies in this context. We can’t use atomic bombs because of the association with an horrific event. We can’t use kitten sneezes because if you worked out what would happen if all the kittens in the world were to sneeze that much, you’d discover that they’d all rupture their internal organs and die. You can’t use microwave ovens, because it doesn’t perfectly represent the process (even though noone has claimed that it does). It seems that the only suitable analogy is :
adding CO2 to our atmosphere is like adding CO2 to our atmosphere.
The problem with this is that it’s not an analogy. The whole point of an analogy is to try and illustrate something about a complex process to those who may not have the background to understand the details. It’s a fairly standard public engagement strategy and if it’s not allowed in climate science, then we really aren’t doing anyone any favours.
Roger finishes his post with the following comment,
Thus, while added CO2 and other human and natural climate forcings certainly can have an effect on large scale circulation features which could exacerbate droughts and fires, the analogy to a microwave that Kevin presented to convince the audience regarding the importance of added surface heating from the radiative effect of the increase of atmospheric CO2 is scientifically incorrect.
Indeed, when we perform model sensitivity experiments, we find that biogeochemical effect of added CO2 on plants (and the feedback to weather) and of land use change are much larger effects on this time and spatial scale.
Now, I’m sure that he may well find this in his research. However, I’m not convinced that many others do or, if they do, they likely see these effects as being in addition to the influence of increased atmospheric CO2 concentrations. Maybe this explains why Roger never seems to refer to any papers other than those on which he is an author (unless he’s criticising one). Personally, I’m much more concerned about those who fail to make clear that they hold minority scientific views than I am about someone who uses an imperfect analogy (as they all are). I really can’t see how this debate will improve if you can’t even use an analogy without being accused of misrepresenting climate science.