New year, new snow


Remembering my post from last year, when snowfall unleashed much irony-free snowman-building fun; here we are again, with the wonder of the white stuff charming the average Londoner.

One difference is that there is a lot more on Twitter this year about #uksnow and the tweet-mining UK snow map is now at version 2.0.

However, many people are trying to figure out the relationship between the colder winters we are facing, versus climate change and global warming. In his Comment is Free post on the Guardian today, Robert Henson differentiates between the overall trends of climate change:

What’s different now is that climate change is gradually shifting the odds toward record-hot summers and away from record-cold winters. The latter aren’t impossible; they’re just increasingly hard to get, like scoring a straight flush on one trip to Vegas and a royal flush the next.

It’s also critical to remember the “global” in global warming. Even if every inch of land in the northern hemisphere were unusually cold, that would only represent 20% of Earth’s surface. There’s plenty of warmth elsewhere around the world…

and the cause of the current cold weather:

If you’re craving a scapegoat for this winter, consider the Arctic oscillation. The AO is a measure of north-south differences in air pressure between the northern midlatitudes and polar regions. When the AO is positive, pressures are unusually high to the south and low to the north. This helps shuttle weather systems quickly across the Atlantic, often bringing warm, wet conditions to Europe. In the past month, however, the AO has dipped to astoundingly low levels – among the lowest observed in the past 60 years. This has gummed up the hemisphere’s usual west-to-east flow with huge “blocking highs” that route frigid air southward.

Why is this important? We are all trying to judge the evidence of major environmental change. Individual action is obviously no substitute for government commitment, but in polluting societies, the sum of individual actions will be significant. The persuasion to change will be based on our perception of what is happening in the world. Confusion is more likely to result in inaction.

Henson’s  post is also headed by the photo “Baboons at Knowsley Safari Park try to keep warm with hot potatoes.” You are going to have a look now, aren’t you?