I was chatting with some people from my agency about how to talk to the press about this drought. (This is not a problem for me, mind you. The press does not contact me.) Reporters keep wanting to know whether we can attribute this drought to climate change. There are a bunch of answers to that, mostly variations on “we don’t know.” One answer is, ‘we’ll know in retrospect’; reporters apparently don’t want to wait a couple decades to know what to call this drought. The problem with attributing this drought to climate change is that Californian hydrology has always had a ton of variance. This is the third worst two-year drought since we’ve been keeping records, but we are still within historical variance. (Shoot. For that matter, historical variance goes way outside the bounds we’re used to. Here’s a write-up of a neat tree ring study that shows paleodroughts that lasted for centuries.) In one sense that is kinda handy. At a talk I went to last summer, the guy from PG&E said that because they had to build their hydropower generation facilities to handle such a wide range of flows, they don’t expect to have to replace their hydropower facilities for about a decade. Even though they’re seeing more high flows, and believe they’ll see floods more often as spring snow turns to spring rains, they’ll still be within the range of flows they designed for. But it does mean that we can’t say for certain that this unusual drought event is from climate change.
The conversation turned to what to say about the concept of “the new normal”. The Planning and Conservation League is promoting the concept that this drought will be “the new normal” under climate change, and what should we say about that? That’s a little rough too. The climate will change steadily for at least a century; we don’t know where it will stabilize. For as long as we can realistically foresee, normal will be continuous change. So when reporters ask if this drought will be the new normal at the end of that? I suggested “Dear god. We hope so.”, but I didn’t see that in the papers this morning. This is why my work doesn’t let me out in public.