Was 2012 the weirdest year for weather?

by Geoffrey Dobson

Roger Harrabin is the Environment Analyst for the BBC, and maintains close links with green organisations like the World Wildlife Fund and the Tyndall Centre. In 2006 he organized the “28-gate” meeting of BBC executives with climate change activists at which they decided that only positive messages about the “Anthropogenic Global Warming” theory should be broadcast on the BBC. No skeptic scientists were invited to that meeting, after which the BBC decided that it was in the public interest to exclude any skeptic opinion from broadcasts.

On October 18 2012 Harrabin wrote this:

<<The UK has experienced its “weirdest” weather on record in the past few months, scientists say. The driest spring for over a century gave way to the wettest recorded April to June in a dramatic turnaround never documented before. The scientists said there was no evidence that the weather changes were a result of Man-made climate change. But experts from three bodies warned the UK must plan for periodic swings of drought conditions and flooding. The warning came from the Environment Agency, Met Office and Centre for Ecology & Hydrology (CEH) at a joint briefing in London. Terry Marsh, from the CEH, said there was no close modern precedent for the extraordinary switch in river flows. The nearest comparison was 1903 but this year was, he said, truly remarkable. >>

And on January 17th 2013 he wrote:

<<The UK Chief Scientist tells me weather extremes now worry scientists as much or more than overall global warming. “If this gets worse, how are farmers going to operate?” he asks. Yet at the same time there’s a relentless spread of climate confusion in parts of the media. The Met Office, a world-leading purveyor of climate information, recently suffered reputational damage that will increase public confusion over whether climate change is important at all. Scientists have been puzzling for some time over exactly what combination of factors is preventing the earth getting even warmer – maybe changes in solar activity, ocean currents or emissions of aerosol pollution. >>

"For the next hundred years the weather will be perfectly normal, but UK Met Office long-term climate predictions will become more and more divorced from reality - just like me"

Harrabin makes contradictory statements in the above two reports. In the first he admits that “The scientists said there was no evidence that the weather changes were a result of Man-made change”, and then in the second says that “The UK Chief Scientist tells me weather extremes now worry scientists as much or more than overall global warming”.

As Met Office predictions of ever increasing temperatures during the 21st century are failing to come true the message on the BBC is slowly changing. We have gone from “Global Warming” to “Climate Change” and now to “Extreme Weather”. The new proposal is that because the global climate warmed slightly during the twentieth century, the world is now experiencing more extreme weather events like hurricanes, droughts, and torrential rain. Even the revered IPCC does not subscribe to this view, but it does not stop the BBC promoting it. There is no evidence that extreme weather events are any more frequent or severe now than they ever have been. In 1929 the New York Times had a headline “Strange weather has swept the world”. A brief search of UK weather records for the late 20th century shows that 1947 and 1963 were fairly extreme. Hurricanes in the Carribean during 2012 were less frequent than in many earlier years. Tropical storm Sandy was particularly devastating simply because it hit New York rather than heading harmlessly out over the Atlantic.

Away from the BBC/ Met Office propaganda machine, weather presenters have been admitting that the extreme swings in weather during 2012 have been caused by shifts in the position of the jet stream. So what does this mean?

Jet streams are fast flowing, narrow air currents found in the upper atmosphere of the Earth. The major jet streams are westerly winds.. The strongest jet streams are the polar jets, at around 7–12 km (23,000–39,000 ft) above sea level The northern hemisphere polar jet flows on average over the middle to northern latitudes at about 60°N, but it can swing as far south as 50°N. (The British Isles lie between 50°N and 58°N). However their paths typically wander about as they flow from west to east. Jet streams may start, stop, split into two or more parts, combine into one stream, or flow in various directions including the opposite direction of most of the jet

Jet streams are caused by a combination of a planet’s rotation on its axis and atmospheric heating. They form at boundaries of adjacent air masses with significant differences in temperature, such as the cold air of the polar region and the warmer air towards the equator.

The main commercial relevance of the jet streams is in air travel, as flight time can be dramatically affected by either flying with the flow or against the flow.

Meteorologists use the location of the Atlantic jet stream as an aid in weather forecasting. It acts as a sort of conveyor belt carrying wet weather systems from the Carribean across the Atlantic to Northern Europe.

The factors that influence the flow of the jet stream are the landmasses and the “Coriolis Effect”. Landmasses interrupt the flow of the jet stream through friction and temperature differences, whilst the spinning nature of the earth accentuates these changes. So the jet stream meanders eastwards across the earth, creating an ever-changing state of flux and subsequent temperature differences.

The latitude of the jet stream changes in an unpredictable (chaotic) manner Since 2007 It has been at an abnormally low latitude across the UK, lying closer to the English Channel, around 50°N rather than its more usual north of Scotland latitude of around 60°N. This led the frequent and more intense rainfall, that normally affects Scotland, to arrive over England. We experienced a few years of very mixed weather. . However in the early part of 2012 the jet stream swung well to the North of Scotland, leading to hot, dry weather in England. The Met Office at the time predicted that we should now expect more frequent droughts in Southern England because of Climate Change. Hosepipe bans were duly enforced by the Environment agency. (The same thing happened in 1976, but at that time nobody had heard of global warming or climate change).

In the middle of 2012 the jet stream suddenly moved back South over the Channel and the UK experienced a very wet end of the year. At the moment it is kinked running at 60°N over the Atlantic and then due South over the UK down to France where it returns to its usual West-East course. This has brought on the winter weather we are now experiencing. Next week nobody really knows what will happen. A good evens bet is that the weather will be much the same as now. In summary it all depends what the jet stream does next.

/span