Causality Between Freezing Winters and Global Warming?
Updated January 4, 12:24, Copenhagen Time.
Further reading: In Bundle Up, It’s Global Warming, New York Times op-ed contributor, Judah Cohen, advances the argument that melting sea ice in the Arctic increases snow fall in the Himalayas. And that this cools the jet stream which then brings cooler weather to large parts of the world, including Europe. Follow the link above to read Cohen’s full argument. Below is the original Earth & Science post on the topic.
Again this year, Europe was shut down by an unusually cold winter. The airport of Charles de Gaulle, the European bottleneck of intercontinental air traffic in Paris, was even more chaotic than usual (I was there – see photo.) And today I was skiing across one of the many frozen lakes outside of Gothenburg, Sweden, in temperatures nearing -20° C.
But what does all of this freezing say about global warming?
Well, here are some of the questions that arose in my frozen brain while I was skiing: What exactly is the difference between weather and climate? And are the colder-than-usual winters in Northern Europe related to climate change or are they refuting it?
In other words: Why are my fingers so frigging cold from taking photographs if the Earth is warming?
Russian scientists have already suggested that the colder than usual winters do not dispute global climate change but are in fact induced by it. Due to melting sea ice in the Barents Sea, the argument goes, the atmospheric dynamics are changing in a way that bring ice-winters to Europe.
But others say that such arguments, while somewhat plausible, may not be the best or even a necessary explanation for the link between a warming world and colder winters. A better approach to understanding this may simply be to distinguish between weather and climate; and to understand that sometimes there isn’t any link.
Scandinavia, to stay in Northern Europe for an example, has just experienced a second and consecutive, unusually cold winter. But that may just be a normal anomaly between weather and climate.
While the weather fluctuates from warm to cold on a small-scale time-frame, the global temperature trend is rising consistently towards a long-term image of a warming world. The frigid winters in Northern Europe, according to the last argument, are thus totally normal short-term variations within a different long-term trend.
Let’s look at definitions.
According to the Oxford American Dictionary, the distinction between weather and climate goes something like this:
- Weather is characterized by momentary observations. The weather is the here and the now – the rain and the snow.
- And the climate, on the other hand, is the weather measured in a specific area over an extended period of time.
- Thus the colder-than-usual winters of 2009 and 2010 in Northern Europe are examples of cold weather. And the climate is the overall trend that characterizes this weather as not just cold, but unusually cold.
These are thoughts from a brief trip of skiing. Please comment above to shoot down inconsistencies.
Is it the job of researchers to define causalities?
Thinking about the difference between weather and climate may not just be a useful way of understanding cold winters — it may also be a fruitful way of approaching climate research in general.
Interesting questions for the future – and continuously approached by climate scientists – are the multiple ways in which weather is and will become affected by changes induced by global warming.
They have to do with causality.
But is it fruitful for scientists to venture into the dodgy field of causalities? I would argue that it is not just fruitful — it is necessary. But when doing to, it is equally important to understand the incremental process of such a journey. It needs to be OK to get lost, make mistakes and then slowly get back on course.
When scientists are saying that the future will bring more of the strongest categories of hurricanes due to global warming, for example, it is a prediction that bridges climate change and changes in weather causally. And such predictions don’t just help us prepare for the future. They make policy making more informed and stress the urgency of action in an intelligent manner.
But such claims are notoriously dangerous to pose and though a standing challenge seems to be to answer the ‘when’ and the ‘to what extent’ global warming and changes in weather are related, pinpointing their relationship can only be done slowly — with a bunch of detours and mistakes — and will have to target a variety of specific weather phenomena in a variety of specific locations.
The challenge is, in other words, a complex affair that seems to resemble an incremental journey much more than an explanation. The better journalists and the public understand this, the less dramatic the scientific journey will be — and the more interesting.
Whether colder winters in Northern Europe can be seen as an outcome of global warming is uncertain. Right now, it seems, it is more likely that the frigid temps of Scandinavia is a reminder that the link between weather and climate is not always explained the best in causal terms.
Time and science are the factors that will help understand how climate and changes in weather are related – in this particular case and in other particular cases in the future.