Met Office calling on “Anthropogenic aerosol forcing”

Posted: June 24, 2013 by tchannon in alarmism, media, Uncertainty, wind

It’s a news release from today (but was embargoed earlier, fed to press) so here it is

June 2013 – New research from the Met Office has raised the possibility that man-made aerosols, industrial pollution, may have impacted the number of Atlantic hurricanes.

The paper, published in Nature Geoscience today, suggests aerosols may have suppressed the number of Atlantic hurricanes over the 20th Century and even controlled the decade-to-decade changes in the number of hurricanes.

Says Nature Geoscience Letters.

Anthropogenic aerosol forcing of Atlantic tropical storms
N. J. Dunstone, D. M. Smith, B. B. B. Booth, L. Hermanson & R. Eade

http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1854.html

Researchers found that aerosols make clouds brighter, causing them to reflect more energy from the sun back into space. This impacts ocean temperatures and tropical circulation patterns, effectively making conditions less favourable for hurricanes.

This interaction between aerosols and clouds is a process that is now being included in some of the latest generation climate models.

Dr Nick Dunstone, a Met Office climate prediction scientist and lead author of the research, said: “Industrial emissions from America and Europe over the 20th Century have cooled the North Atlantic relative to other regions of the ocean. Our research suggests that this alters tropical atmosphere circulation – making it less likely that hurricanes will form.

“Since the introduction of the clean air-acts in the 1980s, concentrations of aerosols over the North Atlantic have reduced and model results suggest that this will have contributed to recent increases in hurricane numbers. On the other hand, the reduction in aerosols has been beneficial for human health and has been linked to the recovery of Sahel rains since the devastating drought in the 1980s.”

It has long been known that North Atlantic hurricane activity has distinct long-timescale variability. Dr Doug Smith, a Met Office research fellow and co-author of the study, said: “We saw relatively quiet periods between 1900-20 and then again from 1970-80, and active periods between 1930-60 and since 1995. On average, active periods have 40% more hurricanes.”

When the authors include changes in man-made aerosol emissions in the latest Met Office Hadley Centre model, which includes a comprehensive treatment of aerosol-cloud interactions, they can reproduce much of the decade-to-decade variability in Atlantic hurricane activity. This supports evidence of a link between the two.

Dr Ben Booth, a Met Office climate processes scientist and another co-author of the study says: “This study, together with work we published last year, suggests that there may be a greater role than previously thought for man-made influence on regional climate changes that have profound impacts on society.”

This study motivates future international collaborative research because modelling the impact of aerosols is one of the largest uncertainties in climate science – particularly true for aerosol-cloud interactions now being incorporated in the latest generation of climate models.

Taken at face value, this study suggests the number of Atlantic hurricanes over the next couple of decades will depend on future aerosol emissions and how they interact with natural cycles in the North Atlantic.
http://www.metoffice.gov.uk/news/releases/archive/2013/atlantic-hurricane

Comments anyone?

There is a supplementary PDF.

Tim

Comments
  1. Lance Wallace says:

    Hansen has said that the observational data on aerosols is inadequate (in fact the major missing factor) due in part to the failure of a planned satellite observatory to reach orbit. So how can any paper focusing on aerosols be taken seriously if aerosol concentrations are so uncertain?

  2. colliemum says:

    Well, as long as they can blame us humans for whatever is happening with the weather …. !
    I remember the times in the 1950s/60s, when weather events were blamed on the atomic bomb, and the nuclear tests in the atmosphere.
    It seems there’s a set of people who’ll never be content unless they can blame us for whatever is happening. They must be the progeny of the strict Puritans, who couldn’t bear to see people being happy and enjoying their lives.
    Sad, really.

  3. Stephen Richards says:

    My B God, what will they do next to support their crap. This not reserch! It’s think of an excuse, double it, turn it upside down, twist it a bit et voilà it fits.

    These are not scientist. What the hell is the world coming to.

    “New research from the Met Office has raised the possibility that man-made aerosols”.

    This is the key to how little they know and that’s nothing. “raised the possibility” indeed. Get out of here you clowns. Where’s that half-wit B. perhaps he could shed some more stupidity on this. [mod: altered, try to stay the right side of libel please ]

  4. Since the introduction of the clean air-acts in the 1980s, concentrations of aerosols over the North Atlantic have reduced and model results suggest that this will have contributed to recent increases in hurricane numbers

    Or perhaps it might just be the AMO.

    MMMMM???

  5. frankpwhite says:

    Cloud albedo is the most seriously deficient of all atmospheric phenomena modeled.

    So how can the Met have confidence in modeling the effect of aerosols on cloud albedo?

    Seems to me you have to get the first-order effects right before you can have confidence in your assessment of second-order effects.

    Cloud is not some trivial variable: on average cloud covers about 50% of the planet biased toward the world ocean. The average albedo of cloud is about 60% and of the unclouded ocean, about 10%.

    Small variations in the physical properties of clouds would indeed affect climate and weather. But the situation is that until clouds are properly modeled we will have these speculative papers that rely on argumentum ad ignorantiam.

    This is an odd form of that fallacy, which is usually rendered “absence of evidence is not evidence of absence”. What we have with clouds is “absence of evidence allow us to speculate whaterver we please”.

    This approach leads to the correlation fallacy, such as the well-know example described by Yule in 1926: the correlation between the fall in the proportion of all marriages in the Church of England and the fall in the mortality rate between 1866 and 1911

    Economists have developed methods to deal with spurious correlation because it is rampant in time series data analysis. Based on an econometric technique called polynomial cointegration analysis an Israeli group concluded,

    “We have shown that anthropogenic forcings do not polynomially cointegrate with global temperature and solar irradiance. Therefore, data for 1880–2007 do not support the anthropogenic interpretation of global warming during this period.”

    Beenstock, Reingewertz, and Paldor, Polynomial cointegration tests of anthropogenic impact on global warming, Earth Syst. Dynam. Discuss., 3, 561–596, 2012

    URL: http://www.earth-syst-dynam-discuss.net/3/561/2012/esdd-3-561-2012.html

  6. hunter says:

    I wonder if they even bothered to look at hurricane frequency over time?

    Google image search link on hurricane historical frequency chart

    And I wonder why lazy journalists do not bother to do their job?
    sorry about the less-than-great link. [mod: fixed ]

  7. oldbrew says:

    ‘Model results suggest’
    ‘This study, together with work we published last year, suggests’
    ‘supports evidence of a link’
    ‘Our research suggests that’
    ‘The paper, published in Nature Geoscience today, suggests aerosols may have…’
    ‘Taken at face value, this study suggests’

    Give us a break.

  8. Paul Vaughan says:

    Total BS on a level that just instigates anger.

  9. vukcevic says:

    Here is another hypothesis with some ‘predictive’ power
    http://www.vukcevic.talktalk.net/NAHs.htm

  10. craigm350 says:

    Reblogged this on CraigM350 and commented:
    Smelled a bit when I read the churnalists reports. Ryan Maue’s hurricane/ts charts also counter the supposed increase. My big pondering is hasn’t our lovely clean air been counteracted by India and China (and many others) – for the same period? Presume this paper is another attempt at a get out of jail card for their Med climate predictions going bust?
    Ryan M’s charts http://craigm350.wordpress.com/2013/06/25/man-made-hurricanes/

  11. catweazle666 says:

    The Met Office?

    Sorry, can’t be bothered.

    Is it “worse than we thought”?

  12. Roger Andrews says:

    In the subject paper Dunstone et al claim:

    “In simulations with a model that comprehensively incorporates aerosol effects (HadGEM2-ES), decadal variability in tropical storm frequency is well reproduced …. (These) results raise the possibility that external factors, particularly anthropogenic aerosols, could be the dominant cause of historical tropical storm variability,”

    But a paper published at about the same time by Zhang et al, and presumably based on the same data, reaches a different conclusion:

    “(T)he aerosol effects simulated in HadGEM2-ES cannot account for the observed anticorrelation between detrended multidecadal surface and subsurface temperature variations in the tropical North Atlantic. These discrepancies cast considerable doubt on the claim that aerosol forcing drives the bulk of this multidecadal variability.”

    http://journals.ametsoc.org/doi/abs/10.1175/JAS-D-12-0331.1

  13. Ulric Lyons says:

    Paul H is on it, that’s the AMO signal: http://i37.tinypic.com/14ln95l.jpg
    That’s not driven by industrial aerosols. If anything, Atlantic hurricanes are retarded by Saharan dust storms.

  14. Roger Andrews says:

    ‘Dr Nick Dunstone, a Met Office climate prediction scientist and lead author of the research, said: “Industrial emissions from America and Europe over the 20th Century have cooled the North Atlantic relative to other regions of the ocean.” ‘

    Not according to the data:


  15. tckev says:

    My study of “Anthropogenic aerosol forcing of Atlantic tropical storms by N. J. Dunstone, D. M. Smith, B. B. B. Booth, L. Hermanson & R. Eade” strongly suggests that the authors have been far too long at the grant trough and should consider future employment undertaking even less arduous tasks.

  16. Tenuc says:

    As usual, the Met Office have shown themselves up as complete twots. These jokers make so many wrong assumptions when building their models that the out-puts are useless, unless you have an agenda to push.

    The majority of industrial aerosols never make it to the stratosphere and are quickly ‘washed out’ by rainfall. Nature produces far more climate effecting aerosols in a year than mankind has done over the thousands of years since we left the oceans.

    Volcanoes, deserts, even algae and plankton are major producers persistent aerosols – mankind just producing a puff in the air.

    The paper itself is full of weasel words, and reads more like a sales pitch than real science. TIme we stopped funding this bunch of complete aerosols and spent the money helping the aged and poor with their needlessly inflated energy bills.

    Sorry about the rant, but I just can’t avoid getting angry when confronted by such rubbish masquerading as science.

  17. mwhite says:

    ” Earth’s stratosphere is as clear as it’s been in more than 50 years. University of Colorado climate scientist Richard Keen knows this because he’s been watching lunar eclipses.”

    http://spaceweather.com/archive.php?view=1&day=15&month=12&year=2011

    “This is timely and important because the state of the stratosphere affects climate; a clear stratosphere “lets the sunshine in” to warm the Earth below. At a 2008 SORCE conference Keen reported that “The lunar eclipse record indicates a clear stratosphere over the past decade, and that this has contributed about 0.2 degrees to recent warming.”

    Just to muddy the water