The cold in the United States had the climate science deniers going all out to cast doubt on the simple fact that our planet is warming and we are the main cause for that. With folks like Trump saying some interesting things:
Of course, a single weather event in one place cannot be used to show that our planet isn’t warming; after all it’s called global warming for a reason.
Funny thing is that the related headlines feature on Twitter made that really obvious with the articles ‘Winter Does Not Disprove Global Warming‘, ‘In Case You Forgot, Cold Weather Doesn’t Disprove Global Warming‘, and ‘Dear Donald Trump: Winter Does Not Disprove Global Warming.’ Always nice to see a feature on a social media website actually helping with countering misinformation.
What people like Trump do and say during winter happens every year. Personally I’ve been dealing with this kind of nonsense since 2011 when I released a video about this very subject. So this behaviour doesn’t surprise me at all.
However, I do get surprised when climate scientists start adding to this kind of nonsense. Which is what Roy Spencer did with his blog post ‘Does Global Warming Theory Predict Record Cold?‘ that very eloquently stated the following:
That’s it. No further context, reasoning or citing of relevant articles.
Technically you could consider this a correct statement, yet it’s wrong on so many levels. Let me cite something from my blog post ‘Winter, Weather, And Climate Science Deniers‘:
The surprising thing is that the cold weather in the United States and the very warm weather here in Western Europe are linked. And both are linked to changes in our climate thanks to our warming world. But let me start with why the United States is so cold and Western Europe is so warm.
What’s causing this is the jet stream making some odd and long loops across the Northern Hemisphere. One of these loops is over the United States, allowing the cold Arctic air to displace itself towards the United States. It’s this Arctic air that’s making it so cold, and you can see the loop in the jet stream above the areas where it’s so cold:
Normally the jet stream doesn’t make these kind of twists and turns when it travels around the Northern Hemisphere. They do happen, but the past few years they are more common and tend to be stronger and longer lasting. The reason for this is in how the jet stream works.
The jet stream is caused by the temperature difference between the equator and the North Pole. The cold air in the arctic is denser and because of that the atmosphere isn’t as hight as the warm atmosphere at the equator. This then causes the warm air to flow towards this dip in our planets atmosphere. But it doesn’t move in a straight line because our planet spins (Coriolis effect), this then deflects this moving air to the right causing the jet stream. The colder the arctic is compared to the equator the stronger this jet stream is. When you have a strong jet stream you don’t get these large loops. Just like a fast flowing river will tend to move in a straight line and a slow moving river tends to make all kinds of strange twists and turns.
And this is the point where our warming climate plays a role. When our planet warms it doesn’t do this at the same rate everywhere on the globe. There’s a phenomenon known as polar amplification, where the poles warm a lot faster and more than the equator does. This is happening in the Arctic and this is causing the temperature difference between the North Pole and the Equator to decrease; which weakens the jet stream. This is what is causing a lot of the weird weather we’ve seen the past couple of years:
Our planet is warming and this can have some surprising effects; like setting the conditions for extreme cold.
That our planets climate is complex and can act in surprising ways is nothing new in climatology and someone like Spencer should know this. Not providing this context, or at least acknowledging this, is extremely misleading. Especially when cold events are becoming more rare.