this is on the path to being thoroughly debunked (the climate change models never supported this...), but there's too many things going on right now to get a clear signal, so it will hang around for a while. and, the media loves it because it creates a single cause for all weather. it makes it easier for end consumers to understand, even though it's wrong. from a legal perspective, trying to argue for global warming due to greenhouse gasses and solar cooling in the northern hemisphere at the same time appears to be a contradiction; it's too subtle for the masses, so the media will continue to push something like this instead.
but i think the weight of the evidence suggests that she's got this backwards. she's got the heat flowing in the wrong direction. i'm oversimplifying rather dramatically, but the second law pushes hot to cold. these dips in the jetstream should indicate decreasing entropy. the idea that this can result from increasing entropy is not really coherent. which is why it doesn't appear in any of the models.
and, in fact, we've recently had some studies come out that link the weakening vortex to a decrease in solar output and this idea of "heat burial" in the pacific. this makes far more sense.
i was referring primarily to the mann study released a few months ago on pacific heat burial and the relevant oscillation. this jet stream pattern seems to be tied to a "blob" of warm water in the pacific.
but, there's an increasing understanding that dips in solar output have a dramatic effect on the jetsream over the northern hemisphere, creating these break-ups in the vortex and streaks of cold air moving down. this isn't a climate denier argument; it operates independently and is more related to the mechanism underlying the milankovitch theory. it's very specific to the northern latitudes.
the idea is not new. i've found it in introductory textbooks on google books. but it's apparently been very speculative, because the mechanism has not been understood. i mean, they've got all this data and this strong correlation, but they couldn't really make sense of it.
when i said an "increasing understanding", what i meant was that researchers are watching this happen and beginning to understand it better.
i believe the best way into this is through mike lockwood.
climate science is something i need to rely on experts for (i'm trained in math, mostly), but the way i'd conceive of what they're saying is to think of the earth as a body of water being hit by electricity - it's maybe orders of magnitude off most of the time, but an aurora demonstrates that it's a roughly useful intuitive model.
so, this energy is hitting the earth and sending wave shocks in whatever direction. one of the consequences of this is that it keeps the polar vortex bottled up around the pole.
now, if you lessen that, the vortex can start to break apart - and if you do away with it all together, it takes over, setting off a snowball earth scenario. what we want is the right balance. but, of course, we can't control the sun.
the idea is that modulations in this stream of energy - even small ones, that are seemingly trivial - can have an effect on how the jetstream moves. increases would bottle it up further, whereas decreases would let it loose, creating these wavy patterns. that would be consistent with what we're seeing - very cold in eastern north america and very warm in western north america. and, in fact there's a historically discernible pattern that correlates well with this.
that doesn't really have anything to do with the concentration of greenhouse gasses, the greenhouse effect or the global mean temperature. it just has to do with how the energy is distributed and how it's affected by the weakening vortex. if you were to add it up, it would balance out. that balancing is going to uphold the increasing mean temperature, even as the eastern seaboard is having record cold winters - because the west is hogging all the heat. and, it's something that's been happening for basically ever, whenever we see solar minima.