Migration north

I think this is much too narrow of logic. The polar ice caps are still melting at an alarming rate. This is changing the salinity of the oceans, thus the air currents. We are in transition, nothing will be normal for a long time. For those that snowbird, they will have to change their patterns and locations just like all the other birds will.

This is evidently what is going on. The Arctic "air mass" is breaking into pieces (the polar atmospheric waves {Rossby Waves} are detaching huge blobs the size of half continents) which drift down unfortunately over North America (some meteorologists are popularizing these massive cold air detachments as "....polar vortices..." ). There is A polar vortex; it used to be a single large-scale cyclone circling both the Arctic (2 low pressure centers) and Antarctic (a single low pressure center). However, it (the northern vortex) has now broken apart into 4, 5, 6, 7+ pieces as the Arctic region warms alarmingly. Haave you seen the northern Alaska temperatures in winter over the past several years? (one detachment of which seems persistent over North America during winter). North America (the US territory) I think, only makes up ~3% of the Earth's total area. So, in light of this, who cares if the US is experiencing exceptionally cold winters ? Statistically, the US land mass experiencing this exceptional cold is so miniscule, in the grand scheme things, it wouldn't contribute much to the sum-total land mass warming/cooling.

Science:

All science (every discipline: medicine, astrophysics, biology, climatology, etc, etc) research is always open to new discovery (ie. old theories fall as new are proven...). You publish reasearch showing x, someone else, 3, 20 years later publishes research showing y. The only constant in scientific research is change over time ;)

Brutal cold for past several days up here. Yesterday 3F/16F; this morning 11F. Anyone returning to the Northeast before May must be very, very desperate :p