In chapter 8.5 of last summer’s US Department of Energy contrarian Red Team climate report they look at a bit of IPCC jargon, namely “Climate Impact Drivers”. Admittedly those three words constitute a phrase that gets our hackles up when jammed together like that. “Climate” is a slow-moving background state of the world or, indeed, various parts of it including small ones. (One can, for instance, legitimately speak of the climate in suburban Boston.) Yes it changes, but to say it has “impacts” conjures up pictures of extreme weather, and as we all know, weather and climate are not the same thing, except when it suits alarmists to fudge the distinction. Climate change can be toward greater mildness. Moreover “drivers” assumes some particular thing or small set of things must be in the driver’s seat, forcing clear and appalling changes on a helpless planet and humanity, whereas climate is so complex no computer can model it with any degree of plausibility and it fluctuates in subtle ways that come and go. Despite which, put those three words together, add in some ambiguity and you have a recipe for foregone conclusions. Even better, give it an acronym (CID in this case) and now you have both foregone conclusions and academic verbiage to dress them up with. But maybe we’re being too suspicious. Because even with the deck stacked in their favour, the IPCC couldn’t make out a case for alarm over Climate Impact Drivers.
The Report quotes the IPCC’s definition of CIDs as: “physical climate system conditions (e.g., means, events, extremes) that affect an element of society or ecosystems.” But to borrow a line from Clint Eastwood’s Jonathan Hemlock, “that doesn’t limit the field much”. What aspect of climate doesn’t affect society or ecosystems? And who’s to say the effects are harmful rather than beneficial, or demonstrate that they wouldn’t have happened anyway? The report goes on:
“Hence CIDs are those features of the weather and climate system of primary interest in assessing the impacts of climate change since they potentially affect humans and the natural world. For instance, under the heading ‘Heat and Cold,’ CIDs are identified as mean air temperature, extreme heat, cold spells and frost. The IPCC also points out that CIDs are not necessarily harm-related: depending on the system in question they can be detrimental, neutral, beneficial or a combination.”
So a CID is… stay with us here… any aspect of the climate system that has any effect on anyone or anything in any direction, good bad or both at once. What would we do without experts? Or acronyms?
The next step is to decide if CIDs are changing due to human influence. And we’ll say right here that even if they are, according to the word salad that passes for analysis so far, who cares? The changes might affect anyone or anything and could be beneficial, trivial or both. But even still, as the DoE team report, the IPCC still couldn’t get anywhere. They reproduced a table listing whether and to what extent an anthropogenic signal could be detected in 33 different CIDs. And the answer was...
“One of the themes of this chapter is that attribution methods used by the IPCC tend to overstate the anthropogenic influence and understate the role of natural variability. Nonetheless a striking feature of that summary table is how few CIDs exhibit an anthropogenic signal sufficient to distinguish them from natural variability. Out of the 33 weather impact categories listed, an anthropogenic signal is asserted with high confidence in only five, and with medium confidence in a further four.”
And even that contorted conclusion overstates things:
“Note that one of the CIDs is an increase in CO2 levels, and since it is a tautology to attribute this to increased CO2 levels this CID can be ignored... Of the five high confidence assertions, two are for changes in average temperatures (air and ocean) hence are not measures of extreme weather. Further, two of the four medium confidence assertions are related to ocean chemistry and thus are likewise not related to extreme weather. The IPCC does not assert a human influence on many non-temperature weather features such as wind, precipitation, flooding, or drought.”
This section concludes by pointing out that the gist of the CID discussion is that the IPCC itself admits “an anthropogenic signal has not emerged in average wind speeds, severe windstorms, tropical cyclones or sand and dust storms, nor is one expected to emerge this century even under an extreme emissions scenario. The same applies to drought and fire weather.” Admittedly the IPCC doesn’t just come out and say so, lest it cause talk. But the DoE report did the decoding. And it should cause talk.
Next week: Extreme Event Attribution
