After the early winter with heavy snow in the North-East of the US, the debate again raises whether this is a result of global warming. On the one side there is the belief that this early winter weather in the North-East of the US is linked to global warming and on the other side there is the remark that one can not have it both. And every position in between.
“But”, would you say, “Couldn’t it be perfectly possible that global warming causes warming as well as snow?”. In a way, that is entirely possible. Sure, if global warming is real this could mean local temperatures go up, maybe even also droughts. Not hard to understand. When because of a polar vortex, cold air blows across a warmer water surface this will produce snow, maybe even lots of it. That is a known phenomenon.
It is of course a bit more complicated than that. The big question is: what is our definition of “global warming”? And do we all use the same definition?
Surprise, surprise, we don’t.
For example, not even a decade ago when we used the term “global warming”, we meant increasing “global average temperature”. From the end of the 1970s until the end of the 1990s average temperatures in the different datasets went up, so at that time that definition was a no brainer.
Yet as time progresses the term “global warming” is more and more used for local events. A heatwave can be intense locally, but not making a dent globally. In the previous definition it wouldn’t even account for global warming, but yet it is given the exact same name.
Global warming can be many things for different people. It could be global, like the average temperature on a global scale. But it could also be an area like the continental US. Even when this is settled, what area means global? Which dataset? What temperatures are anomalous? There is a lot of leeway yet named all the same.
Ill defined terms can be stretched as one goes along. If temperatures go up, one can talk about global warming. We seen that before. But if temperatures of one or more temperature series are not going up, maybe one of the datasets still goes up and still named global warming. If all series stays the same or go down, one could still define warming as having a higher temperature than previous years/decades/centuries. Just focusing on the rising part of the cycle.
More, imagine the confusion when people talk about global warming and actually mean catastrophic anthropogenic global warming. This means it is still possible to talk about a warming even if there isn’t one, even for a decade and a half.
If this teaches us something, there is no common definition of “global warming”.
Then there isn’t much that can’t be explained. Not because of what we see in reality, but because our definition of global warming is so broad that everything fits in.
And then we didn’t even mentioned Climate Change yet, an even broader term. Combine them both and everything is covered…
Trust, yet verify 