Thread by @JohnFinagin

1/10 This is for any of you who aren't as nerdy about weather as I am and who come across climate change deniers. Don't believe anyone who tells you that this is evidence that the climate isn't getting warmer because of a cold winter.

msn.com/en-gb/news/wea…

2/10 The atmosphere is made up of circulatory cells

3/10 The atmosphere is too thin a layer relative to the planet's size for the convection cell to go all the way from equator to poles so in fact there are three cells either side of the equator that work rather like gear wheels driving each other.

4/10 The Earth is spinning which diverts the circulatory patterns to cause our major wind and accompanying weather systems.

5/10 Where two circulatory (Hadley) cells interface a tube of high speed wind is created, usually above 10 kilometres above the Earth's surface. This is called the Jetstream.

6/10 The Jetstream is responsible for much of British weather. It loops like crazy at times and when it does so it pulls warm air up from the south and cold air from the north.

7/10 The mixing of air that results causes all the weather systems we know so well in the UK. Deep loops pull cold air down from the arctic or sometimes hot air from the Sahara. During winter it's much more likely to pull cold air down from the arctic.

8/10 If you think about it the jetstream follows the boundaries between the Hadley cells and these cells are not as neat and tidy as my earlier tweets showed.......

9/10 So when we're putting heat into the atmosphere don't think about it in terms of simple temperature but in terms of energy pumped into the Hadley cells, energising them in turn and destabilising the boundaries making the atmosphere more turbulent.....

10/10 making the jetstream loop deeper, pulling icy air from the north much further south, making winter conditions longer lasting and colder. So a warming global climate can counter-intuitively result in colder winters.