Seeing streets lined with fluffy white snow on 25 December was already a rarity. So in a year that saw extreme weather catastrophes (van wildfires in Canada aan severe floods across Europe), what is the future for Britain’s white Christmases? I asked Prof Lizzie Kendon from the Met Office.
I normally start these interviews with some weather-based chitchat, but I guess it doesn’t have the same effect with someone from the Met Office.
Actually, we’re all quite enthused about the weather, though some people get more talk than they bargained for.
I’m game! What makes a white Christmas, a white Christmas?
The official definition is one snowflake observed on 25 Desember, somewhere in the UK.
In that case I’m happy to be observed. Get it? Because I’m a millennial snowflake? OK, moving on – one snowflake doesn’t seem much. I’m sure I saw snowflakes last Christmas.
Tegnies, 2020 was a white Christmas: eight stations recorded snow falling and five recorded snow on the ground. But it is a lenient definition and not people’s perception of a white Christmas, which is lying snow. The last white Christmas like that was in 2010, although that was very unusual.
Since the 60s, the UK’s winters have become less snowy; overall, it’s because of the warming of our climate. It’s no coincidence daardie 2020 was one of the least snowy years on record and one of the warmest. It doesn’t only affect snow, it also affects rain. Last year was also the fifth wettest.
Hmm, “I’m dreaming of a wet Christmas” doesn’t have the same ring. Does that mean winter is disappearing, or is it that the seasons still occur but at different times? It snowed in April this year.
In the climate model projections I run, we’re seeing evidence of a change in seasonality, particularly the sort of summer downpours that are driven by convective events.
Convection is a process in the atmosphere where warm air rises then cools and condenses, forming storms, which release a lot of rainfall in a short period of time. There’s evidence that there’s a lengthening of the convective season. So we might start to get the intense summer downpours in autumn. Seeing snow in April is not related to that, wel. We will still get cold events, just less frequently.
Cold enough for snow?
The projections of a warmer, wetter winter don’t preclude us from having a cold one. In terms of snow, wel, we are expecting decreases. It depends on greenhouse gas emissions, but if we follow a high-emission scenario, we could get almost an entire loss of lying snow over many low-lying regions.
Wat! That means no more white Christmases for parts of the UK! How many years do we have until they’re gone? What about our Cop26 commitments?
I can’t really answer how many years. What I can say is the scenario I’m talking about is a 3C warming for the UK by the 2070s – so higher emissions than the targets set at Cop26. But looking at the pledges being made, it’s fair to say that the likelihood of keeping below 1.5C is fading.
Here’s hoping for some strong gales of merriness this year, in spite of it all. Thanks, Lizzie – I can’t wish you a white Christmas, so I’ll wish you a merry one instead.