Have weather patterns really been unusual?

Thursday 20 June 2013, 17:31

Paul Hudson Paul Hudson

There’s been much in the press in recent days following the widely publicised ‘Unusual weather’ conference held at the Met Office.

 

The Independent headline was similar to others in the media, advising readers to ‘Stand by for another decade of wet summers’, continuing that the UK was in the midst of a ‘rare’ weather cycle.

 

This cycle, scientists announced, was the Atlantic Multidecadal Oscillation (AMO).

 

But as it turns out, there’s nothing rare or unusual about it at all.

 

The AMO was first identified by researchers nearly 20 years ago, incidentally when I had just begun my career as a forecaster at the Met Office, and describes a natural, cyclical warming and cooling of the North Atlantic Ocean over time.

 

This cycle is known to affect temperatures and rainfall, and alter North American and European summer climate.

 

In the UK, it leads to an increased risk of summers that are wetter than average.

 

It’s also linked with changes in the frequency of Atlantic Hurricanes, and of North American droughts.

 

The 1930’s and 1950’s in North America are dominated by heat records and correlate almost perfectly with a warm AMO.

 

The AMO has a cycle of approximately 70 years and would mean the current warm AMO is likely to last into the next decade.

 

But talk of another decade of wet summers is misleading.

 

If as expected the warm AMO continues then there’s a higher risk of wet summers – but it certainly doesn’t mean every summer will be a washout.

 

It’s worth remembering that one of the warmest, sunniest summers on record happened in 1959 – during the previous warm AMO cycle.

 

The return to much colder winters discussed at the conference has coincided with another natural phenomena – that of low solar activity - which has been shown to be associated with weather patterns that encourage cold winters across the UK and Europe.

 

It goes to show that at a time when it seems that every weather event or climate pattern is linked in some way to man-made climate change, natural weather cycles like the AMO can offer a more straightforward, natural, explanation.

 

Comments

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  • rate this
    +4

    Comment number 1.

    "It goes to show that at a time when it seems that every weather event or climate pattern is linked in some way to man-made climate change, natural weather cycles like the AMO can offer a more straightforward, natural, explanation."

    Well said Mr Hudson, now please keep on saying it only louder and as often as possible!

    I can assure you I for one will not get bored.

  • rate this
    0

    Comment number 2.

    The whole man-made global warming edifice surely cannot withstand gravity much longer! I found the recent Met Office commentary full of contradictions and maybe, just maybe, as the global temperature trajectory fails to conform to the climate models, some important people will dare to see things for what they are.

  • rate this
    0

    Comment number 3.

    Well that certainly makes sense. But how does it sit with this:" ...I then joined the BBC in October 2007, where I divide my time between forecasting and reporting on stories about climate change and its implications for people's everyday lives..."

    On the one hand, you appear to be dismissing the present hysteria about 'extreme' weather - yet on the other, seem to be clinging to the idea that the climate is changing (due to man's activities, presumably - if not, what's the point of bothering, since there's nothing we can do about it?)

  • rate this
    0

    Comment number 4.

    Refreshing.

    And in posthumous respect for one of the most distinguished BBC amateur scientists ever, may I offer a quote
    'Now for global warming. Of course we are going through a period of warming, but so far as human culpability is concerned I am a total sceptic and I fear we are dealing with political manoeuvring. There was, for example, much greater marked warming at the end of the Maunder Minimum; what about the Mediaeval Maximum, when Britain was hotter than it is now? No doubt, the present period of warming will be followed by a period of cooling, as has happened in the past time and time again. After all, the Sun is to a mild extent a variable star and we cannot control it –'
    (The Late) Sir Patrick Moore

  • rate this
    0

    Comment number 5.

    It was refreshing to see some honesty from the Met Office - they finally admit they don't know what is driving the weather. And it follows that they never have. So all the output of their overpriced climate models can be put on the junk heap where they belong. Now they just need to make sure the politicians get the memo.

    And it looks like Mr Hudson really is a sceptic. Bravo!

  • rate this
    0

    Comment number 6.

    I agree with all these comments. All those "experts" at the conference did in fact conclude that they didn't really have the definitive answers-no more than what triggered the last ice age(and its retreat). Earth controls man-not the other way round.Homo Sapiens is a transient species-destined to become fossilised in a microscopic band of stratigraphy in a post himalayan mountain chain some 300m. years hence (that's nothing in Earth Time).Even then the Sun will still be shining steadily and Earth leisurely rotating to new oceans,continents and life forms.

  • rate this
    0

    Comment number 7.

    While sceptics are on a roll just to clarify the mainstream sceptic position with a couple more quotes

    'Claims that the earth has been warming, that there is a Greenhouse Effect, and that man’s activity have contributed to warming are trivially true, but essentially meaningless.' Richard Lindzen

    'There is no worse lie than a truth misunderstood by those who hear it.' William James.

  • rate this
    0

    Comment number 8.

    Not sure where temperature comes into this?

    If the AMO is in a warm phase, then why have UK temps been dropping on average over the past 10 years?

    Does this just concern rainfall?

  • rate this
    -2

    Comment number 9.

    Before we all start falling for the trap of "it's cool in my backyard, therefore global warming isn't happening", it is worth noting that NOAA have just released their May 2013 update. This May was the third warmest May in the last 134 year. The year to date is the 8th warmest.

    2000 - 2009 was the warmest decade on record. 2010 was the warmest year on record.

    The latest research shows that after 5000 years of gradual cooling, 1900 -1909 was cooler that 95% of the entire Holocene period (11,300 years). By contrast, 2000 -2009 was warmer than 75% of the entire Holocene. We have not been this warm for 5000 years now.

  • rate this
    -4

    Comment number 10.

    9. Edward

    You just saved me a post.

    Thanks.

  • rate this
    0

    Comment number 11.

    #9.Edward
    "Before we all start falling for the trap of "it's cool in my backyard, therefore global warming isn't happening", it is worth noting that NOAA have just released their May 2013 update. This May was the third warmest May in the last 134 year. "
    NOAA has a bigger increase in the global anomaly than GISS, RSS and UAH for May. This seems to be mostly due to an increase in the SH anomaly while the others show falls, which looks a bit odd. In turn, this seems to be due mainly to an increase in the SH land anomaly.
    The figures suggest that the SH anomalies are almost as high as the NH, but on the other hand the anomaly map doesn't seem to reflect that, possibly due to the absence of any really low anomalies over the land.
    http://www.ncdc.noaa.gov/sotc/service/global/map-blended-mntp/201305.gif

  • rate this
    0

    Comment number 12.

    "This May was the third warmest May in the last 134 year."
    Quite possibly. We appear to be in a warm period similar to the Medieval, Roman, and Minoan Warm periods that preceded it. Unfortunately there were no thermometers that might have given more accurate measurements for those periods. Unfortunately, ancient civilisations that thrived during those periods were also not able to take their non-existent thermometers all over most of the planet like satellites do.

    For what one moths data is worth, NOAA says May 2013 was tied with 1998 and 2005. So no increase in 15 years then?

  • rate this
    0

    Comment number 13.

    11. QuaesoVeritas

    "NOAA has a bigger increase in the global anomaly than GISS, RSS and UAH for May."

    There are queries/discussions about, from what I can see there are no substantive conclusions to date

    "NCDC’s irreconcilable temperatures in the May 2013 State of the Climate Report"

    http://wattsupwiththat.com/2013/06/20/ncdcs-irreconcilable-temperatures-in-the-state-of-the-climate-report/

    I have no problem with differences between data sets, I look forward to a bit of scientific "competition"! It can only act as a catalyst for understanding.

    The apparent need for all the data sets to "confirm" each other has been a concern. So far the actions of the real world and its inhabitants suggests that it is a scenario that will last for much longer.

    As always time will tell....

  • rate this
    0

    Comment number 14.

    13. greensand

    "....suggests that it is a scenario that will last for much longer"

    should be:-

    ....suggests that it is a scenario that will NOT last for much longer

  • rate this
    -1

    Comment number 15.

    Edward " We have not been this warm for 5000 years now."

    The Vikings who farmed Greenland from 800 to 1200 might disagree.

    You seem to be one of those people who are reluctant to accept facts. Here's another one you're going to find unpalatable - there has been no warming for quite some time neither in my back yard nor in everybody's back yard lumped together. It's called reality. Get used to it.

    No surprise that newdwr54 was going to post the same sort of drivel. It's what true believers do.

    Again its good to see that our host has the good sense to reject the AGW nonsense. Bravo Paul.

  • rate this
    -1

    Comment number 16.

    @9 Edward wrote:

    “ The latest research shows that after 5000 years of gradual cooling, 1900 -1909 was cooler that 95% of the entire Holocene period (11,300 years). By contrast, 2000 -2009 was warmer than 75% of the entire Holocene. We have not been this warm for 5000 years now. “

    What is this 'latest research'?

    P.S. Extra amusement points for mentioning Marcott. ;)

  • rate this
    +1

    Comment number 17.

    More and more data coming to light tends to support my proposition about climate change being entirely attributable to the interaction between bottom up oceanic and top down solar variations with any effect from our emissions being near enough to zero to be indistinguishable from the hugely more powerful natural climate fluctuations.

    I have provided suggestions and data in support regarding the most likely mechanisms and it can only be a matter of time before it becomes obvious to all.

  • rate this
    0

    Comment number 18.

    #13.greensand
    "I have no problem with differences between data sets, I look forward to a bit of scientific "competition"! It can only act as a catalyst for understanding."

    Thanks, I hadn't seen the other comments when I posted.
    "Open Mind" has already responded to the WUWT blog and accuses AW of not taking into account the base period differences between the anomalies, although I haven't looked into it in much detail yet.
    http://tamino.wordpress.com/2013/06/21/shooting-from-the-hip/
    I think a lot of the differences between the various anomalies is down to differences in methodology and coverage. I notice that the NOAA map covered very little of the north and south poles. OTOH, the GISS global anomaly map seems to show more of the poles and there is a large area of sub zero anomalies in antarctica on the GISS map, which is not shown on the NOAA map. I am not sure if this link will work and you may have to reset the parameters:
    http://data.giss.nasa.gov/cgi-bin/gistemp/nmaps.cgi?year_last=2013&month_last=5&sat=4&sst=3&type=anoms&mean_gen=05&year1=2013&year2=2013&base1=1951&base2=1980&radius=1200&pol=reg
    How GISS arrives at it's anomalies for the poles, I don't know.
    There are also differences between UAH and RSS coverage of the poles and I think that might account for part of the differences. Some months this might have a bigger effect than other months.
    Oh for a temperature anomaly series which covers the entire globe in equal detail and accuracy.

  • rate this
    0

    Comment number 19.

    I realised that the GISS anomaly map was not really comparable with the NOAA one, because of hte different base periods.
    Here is one using the same base period as NOAA:
    http://data.giss.nasa.gov/cgi-bin/gistemp/nmaps.cgi?year_last=2013&month_last=5&sat=4&sst=3&type=anoms&mean_gen=05&year1=2013&year2=2013&base1=1981&base2=2010&radius=1200&pol=reg
    The large area of negative anomalies in the antarctic are still there.

  • rate this
    0

    Comment number 20.

    I also notice that on the GISS map using the 1981-2010 base period, the global anomaly is given as 0.17c, compared to the NOAA anomaly for the same period of 0.66c.
    I am not sure if that is due to the "cold" area in the antarctic or if I am doing something wrong.
    Perhaps someone else might know.

 

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Hello, I’m Paul Hudson, weather presenter and climate correspondent for BBC Look North in Yorkshire and Lincolnshire. 

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I worked as a forecaster with the Met Office for nearly 15 years locally and at the international unit, after graduating with first class honours in Geophysics and Planetary physics at the University of Newcastle upon Tyne in 1992. I then joined the BBC in October 2007, where I divide my time between forecasting and reporting on stories about climate change and its implications for people's everyday lives.

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