It doesn’t exactly counter Alen’s claim, but it does target a common, underlying sentiment shared by people who make that sort of argument. People don’t seem to comprehend the idea of a probability distribution (or really any distribution, in the statistical sense). It seems to be a blind spot in our reasoning, similar to the exponential function.

If you tried to embed something here, Brian, WordPress stripped it out…send me an email or a comment with the link and I’ll embed the image for you. -Kate

The red is the blue curve shifted to a higher mean temperature, i.e. through global warming (that’s all the term means: An increase in mean global temperature). The X axis is simply temperature.

Probability density is a funky term, but in essence, the area under the curve corresponds to probability. The area under the entire curve is 1.00, since the probability of *something* happening is 1.

If you want to know how likely something this extreme or more extreme is, draw a line at some threshold; the area under the part of the curve it cuts off is the corresponding probability.

Here, if you want to know the probability of a given temperature or higher, you draw the line marked Threshold at the given temperature. The area under the curve to the right of that line is the probability of temperatures that extreme or higher.

Under the “warming world” red curve, the probability of an extreme event goes up from the older world blue curve. The probability of “VERY” extreme events, formerly so low as to be not considered, also goes up (that’s the part of the red curve that is not also under the blue curve; one example would be the Moscow heat wave).

However, as the temperature goes up, there is *STILL* a portion of the curve over the low-temperature. They just become less likely – they don’t disappear altogether, except at the tail end of the curve (the area on the blue curve that isn’t also under the red curve).

This is very simplistic – for instance, it assumes the shape of the curve doesn’t change as mean temperature rises – but it should get the point across. Global warming – an increase in mean global temperature – does NOT mean no more winters.

This is also just on a more general point than the specific NAO influence – that’s more about ocean currents, which is a rather complex field (did you read the paper at all? If you did, could you follow their methods and discussion?). But it serves to counter the general denialist problem of thinking that the word “warming” precludes any cold at all.

So basically regardless of what happens in the future it will have been predicted and explained by global warming. Just point to one of the two studies and don’t mention the other. Then say “Yup, we knew it all along”.

Not every set of observational data would confirm a warming planet. There are many major indicators of global warming that are clearly predicted to go in a certain direction – for example, the temperature of the planet as a whole, or the sea ice cover in the Arctic. The climate system is so nuanced, though, that some regional and seasonal effects could go either way, such as winter temperatures in regions influenced by circumpolar currents.

Assuming that scientists would cover up past uncertainty in these situations, once they understand what’s going on, is at best naive, and at worst libelous. For every instance of minor scientific uncertainty, how can you accuse them of conspiracy in the future, when the future hasn’t even happened yet? -Kate

http://stephenleahy.net/2010/09/13/arctic-melt-down-is-bringing-harder-winters-and-permanently-altering-weather-patterns/

Thanks for that link, Stephen. It’s awesome that you got to cover IPY – I heard it was a really good conference. -Kate