The Irish Independent this morning has a useful full-page piece by Ed Power in its ‘Weekend Review’ section on the extreme cold spell. He canvassed three perspectives, and I find myself, not for the first time, somewhat at odds with Ray Bates, adjunct professor of meteorology in UCD.
I know Ray quite well, and always enjoy a friendly banter when we meet at conferences. I’ve listened to him speak on numerous occasions. His expertise and integrity is beyond question, but I reckon Ray is a disciple of the cup-half-full school, and appears to enjoy being a counterpoint to the ‘consensus view’ (among climate science, certainly, if not meteorology, a related but quite different discipline). “It is impossible to explain these large [weather] anomalies in terms of global warming”, Ray is quoted below.
He could as easily have pointed out that it is equally impossible to categorically rule out that we may well be experiencing a marked destabilisation in climate patterns. Globally, the evidence for systemic, wide-ranging and non-linear disturbances to climate systems is compelling. Ray appears to poo pooh these by harking back to the 1950s and scares about the possible climate impacts of atomic bomb tests. This is just a little reminiscent of the canard about climate science promising us a new ice age back in the 1970s (a favourite of lazy media commentators).
Meteorology is primarily about the study of weather, and weather is indeed a fickle beast, as Ray quite correctly points out. Climate science is about peering through the ‘noise’ of variability to reveal the underlying longer-term trends. Hence, the two disciplines often do not see eye to eye.
While I don’t share Ray’s view of underlying global warming being a slow-moving phenomenon, I unreservedly accept his bona fides in making the argument. The term ‘sceptic’ has come to be seen as a term of abuse in climate science. Genuine, informed scepticism is both welcome and necessary, and Ray Bates is, in that real sense, a sceptic.
So – is the Arctic weather all our own fault? Are we to blame for the blizzards and the icy mayhem? The mere question provokes a storm of disagreement among climate experts.
Some regard the unseasonable big freeze as irrefutable evidence that decades of human pollution have pushed existing climactic patterns to breaking point, unleashing a vengeful fury of extreme weather.
Others contend the snow storms buffeting the country, trapping thousands in their homes, are simply a statistical anomaly that have little to do with long-term trends in worldwide temperatures.
“The phrase ‘climate change’ may have to be retired in favour of ‘climate disruption’,” says Climatechange.ie founder John Gibbons. “Go back just a few years. In November 2009 we had record floods. January last. . . the worst freeze in 50 years. Now we’re back to it again.”
No single event, he says, can be attributed to climate change (which scientists believe is linked to the warming effects of greenhouse gases resulting from human activity). Cumulatively, however, it is clear profound changes are shaking global weather systems to their core.
“The rate we are seeing weather anomalies indicates something quite serious is happening with the climate system,” he says. “There are few people in expert circles who would disagree. The problem is they can’t tell you what would happen next. It’s like a runaway horse. It’s out of control and you don’t know what it’s going to do.”
There is, he acknowledges, an irony to the fact ‘global warming’ may be responsible for five inches of snow in Dublin. At a scientific level, however, this is a completely logical turn of events.
“When Ireland froze last January, weather stations in Greenland were recording temperature increases in the range of 3.8 to 8.8 degrees centigrade. They were completely off the chart.
“Weather systems are normally held within extremely cold areas such as the Arctic. Essentially, it’s too cold there for the ‘cold’ to move.
“What we’re seeing now is a weakening of the intense cold in the Arctic. That weakening is allowing the Arctic air to ‘slip away’ and so, of course, it lands on us. The cooling we are witnessing is mirrored by a dramatic warming in Greenland.”
Gibbons, an environmental writer and commentator, believes we are only seeing the start of things. “What does climate change and the warming effect tell us? It tells us we are going to get an intensification of storm activity and that we are going to get increased precipitation.
“That can include more snow, which might seem counter-intuitive.
“I know it can be difficult to explain, but snow falling from the sky can be a symptom of. . . increased warming. People are going to say, ‘that’s crazy’. Well, believe it or not — increased warming in cold areas can lead to more snow, not less.”
However, this opinion is not universally shared. “It is impossible to explain these large [weather] anomalies in terms of global warming,” says Ray Bates, adjunct Professor of Meteorology at UCD. “We are having a cold spell at the moment. The past two winters have been quite cold as well — colder than normal, after decades in which there was very little frost. These are local anomalies in the Irish climate.”
That’s not to say global warming hasn’t impacted on the weather, he says. It’s just that the changes are long-term and, compared to the current blizzards, relatively subtle.
“We’ve had a lot of variability in the last few years in Irish weather,” says Prof Bates. “We’ve had very wet summers in 2008 and 2009. We’ve had three winters in which we’ve had a lot of cold weather. We had ice on Sandymount Strand in January 2009.
“This year we have the record November cold spell. These are features of the natural variability in our climate. In the background, we’ve had global warming going on. The main signal of global warming, which we can attribute to greenhouse gas increases, is the rise in sea level, which is occurring at 3.2mm per year.”
Rising sea levels aren’t to be scoffed at. Nonetheless, they are unlikely to have triggered the current severe weather, he says. “A lot of commentators are saying this is a sign of man-made climate change. I wouldn’t agree with that at all. [Climate change] would lead to some extra warming in the atmosphere and to some excess rainfall — but nothing to the extent of the anomalies we have seen in our recent wet summers.
“The rainfall November of last year was 200pc to 300pc above normal. What you’d expect from global warming would be a 6pc or 7pc increase in average rainfall due to temperature increases.”
There is a third school of thought. Some scientists believe global warming is not the only factor behind the weather extremes of the past two years or so. According to Professor Michael Lockwood of the department of meteorology at the University of Reading, changes on the surface of the sun may play a role too.
At the moment, he says, the sun is going through a period of ‘low’ activity, with less sunspot agitation than normal (sunspots are areas of intense heat on the surface of the sun, visible as dark blots). When this is combined with high-altitude jet-stream winds, as is happening presently, it gives rise to a phenomenon he describes as ‘jet-stream blocking’.
Over the next few years, he says, the likely result will be colder winters and heavier snowfall. “It looked last week like we had a blocking event formed. The phenomenon is really a snaking of the jet stream. It can start to pull lower altitude, cold Russian air back in over Europe,” he said.
“November is a pretty good predictor of what December through February is going to be like.”
Not everyone goes along with this. People are seeking an explanation for freak weather when none may exist, says Prof Bates.
“People are always looking for reasons for anomalies. I’m old enough to remember the 1950s, when people were blaming the atomic bomb tests for causing what was considered strange weather. The variability in our climate has always been there and will always be there whilst in the background we have global warming, which is slowly starting to be felt,” he says.
In the opposite camp, Climatechange.ie believes that the extreme weather is likely to grow even more extreme in the decades ahead. “We appear to be at the end of a very long, benign period,” says Gibbons.
“The climactic conditions that allowed humanity to prosper are [over]. We may have to brace for more of this. I think we are in an incredibly dangerous position.
“The time for getting the reins back on the horse is running out. The first thing you’ve got to do in a crisis is recognise there is a crisis.”