So, let’s assume that BOTH the sun AND Arctic warming have something to do with a) cold and snowy winters in the Eastern U.S. and Europe; and, b) some of the other extreme weather happening in other parts of the world. We also assume that we can’t prove ANY of this, OR that this explains any single storm, cold wave, heat wave, flood, hurricane, or flu outbreak (just kidding on the last one). In this case, the future will tell us which is more correct (or if they have nothing to do with recent winters and summers). Another 10 years will give us some great clues. Maybe.
This is one of the big differences between climate study and weather forecasting. We can tell if our forecast verifies the next day, or the next week. Then we can learn from our mistakes. If climate scientists are wrong, they might not know it for 50 years!
If the solar theory is the main explanation, the predicted increase in sunspots should allow for more warming, even in years that don’t have a strong El Nino.
On the other hand (there always should be another hand in science), if the rapid Arctic warming is leading to the persistently negative NAO and AO, we’re in for more rough winters around here and in Europe.
But what if the sunspots don’t increase, AND the Arctic keeps warming? Controversial (but recent amazingly accurate) astrophysicist Piers Corbyn from England says we’re headed into a Mini Ice Age in future decades. Remember, from Part One, he’s a pure “solar” guy, who things global warming is bunk. So, if we do see more cold and stormy winters in the Eastern U.S. and Europe, he’ll claim victory. But so will the global warming people, who will say it’s the Arctic warming and not the sun. Now we’re back where we started, without know if it’s one or the other, or both.
What about next winter, and the ones after that? If either theory were right, odds would favor another cold and snowy winter. This doesn’t guarantee a brutal winter-we can even get mild winters in an overall cold period. But it’s about odds. As Al Gore has mentioned regarding global warming, it’s like loading the dice, so that a certain outcome happens more than you’d expect by chance alone.
As far as this winter is concerned, we have to expect more cold and snow in February, since that persistently negative NAO and AO lead to more blocking patterns. Every time the blocking has eased, it’s gone right back to another negative NAO/AO pattern. But just like last winter, this pattern eventually can break dramatically, leading to a warm spring. Last winter, we went from the snowiest on record to the hottest spring and summer on record. More extremes. Get used to them.