You write: "I will not address the question of whether the probability or intensity of this pattern might be influenced by global warming." Why? What does that mean? That perhaps it's possible to warm up our global climate system and not see "natural" patterns mutate and intensify into harmful "climate change" ? Sorry, but I find it appalling the way so many scientists have been kowtowed but right wing bullies into shooting themselves in the foot with every attempt to inform the public. This isn't a quaint scholastic debate! We are talking about the observed rapid degradation of the world our children will inherit and pretending AGW 'might' not be radically altering ancient patterns is unacceptable.