Fake Banner
    Climate Change Feeds Hurricane Sandy
    By Robert Cooper | October 28th 2012 06:27 PM | 21 comments | Print | E-mail | Track Comments
    About Robert

    I have given up on categories. I did a BA in physics, a PhD in molecular biology, and now a postdoc in a bioengineering department. So call that...

    View Robert's Profile
    Hurricane Sandy, 2012:
    Massive and dangerous Hurricane Sandy has grown to record size as it barrels northeastwards along the North Carolina coast... -Jeff Masters, Weather Underground, Oct. 28 2012.
    Science paper, 2010:
    Fewer but fiercer and more-destructive hurricanes will sweep the Atlantic Basin in the 21st century as climate change continues, a new modeling study by U.S. government researchers suggests. -commentary by Richard Kerr on Bender, M.A. et al., 2010. Science, 327(5964), pp.454–458.
    Hurricane Sandy, 2012
    If ‘Frankenstorm’ pans out to be as powerful and odd as the models currently forecast, then it may be said that this storm will be unique in the annals of American weather history. -Christopher Burt, Weather Underground, Oct. 26, 2012
    Report by the National Research Council, 2010:
    the destructive energy of Atlantic hurricanes is likely to increase in this century as sea surface temperature rises -"America's Climate Choices: Adapting to the Impacts of Climate Change".  National Research Council, National Academies of Sciences, 2010
    Where I sit in New Jersey, we are preparing for a direct hit from a record-setting hurricane.  We all know that no one event can be blamed on climate change.  But this freak storm certainly seems to match the warnings we've gotten over the past decade.  Let's consider what exactly makes Hurricane Sandy so "freak", and whether this freakiness may be a harbinger of the new normal.  There are at least three factors making Hurricane Sandy such a threat: 1) Warm sea surface temperatures, 2) A "blocking pattern" shoving the storm back on shore, 3) A merger with a winter storm.

    1) Warmer oceans.  Global warming has been raising sea surface temperatures around the world.  The water off New England set record highs this year, meaning that Sandy will have more energy to feed from than usual as she churns North.


    Sandy will draw energy from the abnormally warm ocean just off the Atlantic coast.  Note this is in Celsius.  The water off NJ is about 5°F higher than average, and set record highs in 2012. Source: NOAA National Hurricane Center.
    Yes, there are natural variations that affect sea surface temperatures, in particular the Atlantic Multidecadal Oscillation.  But consider the plot below showing North Atlantic temperature changes from normal.  The ~60 year oscillation is clear, but so too is the fact that each peak is stronger than the one before.


    North Atlantic sea surface temperature anomalies (°C). Source: Wang, C.&Dong, S., 2010. Geophys. Res. Lett, 37, p.L08707.
    2) Blocking pattern.  A blocking pattern is essentially when the jet stream gets kinked.  The current kink is pushing Sandy back on shore where most hurricanes would keep veering out to sea.  A recent analysis showed that blocking patterns like this are more likely thanks to a warming Arctic.  As Arctic sea ice keeps melting to new record lows, the darker water absorbs more heat, which it later releases to the atmosphere.  The effect of all this is a weaker jet stream more prone to kinking.

    3) Merging with a winter storm.  Ok, so actually, this one's not climate related.

    Ok, so prediction: rising temperatures will give hurricanes warmer oceans to feed from, and more moisture to dump on us, making them more destructive.  Observation: we are about to get walloped by what looks to be a history-making storm.  Prediction: ocean temperatures will keep rising and blocking patterns will become more frequent.  Observation: Hurricane Sandy is feeding off of record ocean temperatures and a kinked jet stream.

    Now, it is certainly true that we still don't completely understand hurricanes.  It is true that models are not perfect.  It is true that Hurricane Sandy could have happened even without climate change.  It is true that climate change doesn't "cause" an event, just like doping alone won't win you the Tour de France.  And, as always, it is true that we should not draw conclusions from a single event.  So then, is Hurricane Sandy just a freak event, or is she an instructive example of what we should expect more often?  Let's look at a paper just published in PNAS, which put together a long-term data set of hurricane activity based on storm surges.  That means this is not a model – it is empirical evidence from the past 90 years.
    We observe that [hurricane activity is greater in] warm years... than cold years and that the relative difference... is greatest for the most extreme events. -Grinsted, A., Moore, J.C.&Jevrejeva, S., 2012. Proceedings of the National Academy of Sciences.
    Climate change is happening, this is why we care.

    More:

    Comments

    Climate change is real and this is one of the consequences. Although the ones who are in a position to do something to change the carbon footprint only act as if this is a minor inconvenience, as time goes by it will become more evident what this mistake in judgement will cause. Of course, they will probably be able to buy a place to live where they are relatively unaffected, but that will not help the rest of us who do care!

    Hank
    I agree it is happening and that we should care; the problem with using local weather events as evidence is that, like with Irene, it may end up being a lot less than the media is making of it and that breeds derision.  In addition, skeptics can then say since this was a lot less devastating than something like Hurricane Andrew that climate change problems have gone down since 1992.

    Here is hoping this model is as inaccurate as every other weather model ever made; or those people are hurting.  Good article.


    ack in the 1990's Republicans, egged on by their powerful southern tobacco lobbyist, tried to refute the dangers of cigarette smoking. "There's no proof that cigarette smoking is harmful" Republican Bob Dole claimed as he ran for president.
    Today, of course, we know that tobacco executives and Republican congressmen all knew the dangers of cigarette smoking. They just wanted to keep it quiet, for fear the public would demand some sort of ban on smoking or a reclassification of smoking as a narcotic.

    One wonders how many millions of smokers died because Republicans tried to deny the truth to sell everyone on the idea that cigarette smoking was a harmless habit.
    Much like the climate change argument they are putting forth now on behalf of big oil and coal interests

    Hank
    I'd love to see a citation for that Bob Dole quote.  

    Kay Hagan, US Senator from North Carolina, blocks more anti-tobacco rulings from anyone, and she is a Democrat.  Democrats outnumber Republicans by 30% in that state and they love Big Tobacco.

    If this was just a rant about evil smoking, 30 years after the world knew it was bad for us, or you are doing the canvassing for the DNC before the election, cool.  If you are in the reality-based community, though, you need to show some data on how you are justifying this claim that Big Tobacco caused Hurricane Sandy, or whatever you are saying.
    car2nwallaby
    Ah, but speaking of keeping it quiet, where has climate change been in the 2012 elections?
    There is no reason why climate change should be a partisan issue, and in fact, pre-Tea Party it was more a geographical issue than a partisan one, with coal state Democrats opposing strong action and moderate Republicans (e.g. John McCain) co-sponsoring bipartisan bills.  Even now, the sense is that many Republicans in Congress agree with the scientific consensus, but, like many Democrats as well, they are afraid to mention it.  Other than die-hard denialists, the problem is not in beliefs, but in a deficit of courage on both sides.  The only way to change that is to show people why we should care.
    Hank
    I wrote a few articles on this; it isn't an issue because the public has a hierarchy of needs; we are actually back at early 1990s levels of emissions, coal is at 1980s levels of CO2 emissions, and this is what our economy looks like for people who are not government employees.  A president trying to get reelected should not tell 50 million people on food stamps they need to worry about cutting CO2 emissions so China can increase theirs. Obama is campaigning to win, not to appease people he knows are already voting for him no matter what. 

    Science overall is not a campaign issue, and so Romney does not bother to mention it, because scientists don't vote for candidates based on science positions. There are zero people in academia suddenly voting Republican if he talks about climate issues. 
    MikeCrow
    Warm AMO temps seem to bring east coast hurricanes. Some historical info here and here.
    Any ideas on why the positive AMO in ~1870 was so much colder than the one in the 1940's? That was well before the the large increase in co2 from the 70's on.
    Never is a long time.
    car2nwallaby
    Warm AMO temps seem to bring east coast hurricanes
    That's the point.  Why would we want to make it even warmer?  Here's panel (c) from the Wang&Dong paper (must... not make... childish jokes...) showing global sea surface temperatures.


    I suppose some things are just counter intuitive by nature. My every day logic says that if SST is increasing then evaporation is increasing; if evaporation is increasing then SST should be decreasing because of the thermal exchange. If evaporation is increasing then the water vapor content of the atmosphere is increasing thereby increasing the near-surface temperature. Another fine mess you've gotten us into, Ollie.

    Nice article, BTW.

    MikeCrow
    Why would we want to make it even warmer?
    I don't know that we would (though you might be able to argue heat stored in the oceans might be nice to starve off an ice age). But I don't think but a small fraction of that is from us.

    The global graph (panel c) averages out the solar precession between Northern Hemisphere and Southern Hemisphere, that's why the positive excursions are distinct in panel a, as opposed to this one.
    My land surface temps show a fairly flat tropic temperature, slight decline in southern hemisphere, both of which are over whelmed by the northern hemisphere.
    But I think a lot of the problem with temperature averages is extrapolating between measurements, if temps were linear over area, it wouldn't be as bad, and ocean temps are sampled at fewer sites and fewer continuous sites than land temps.
    Never is a long time.
    car2nwallaby
    The global graph (panel c) averages out the solar precession
    Now you've got me confused.  I would not have expected a 23,000 year cycle to show up in a 100 year plot.
    MikeCrow
    No, I was confusing.
    It averages out the Northern and Southern Hemisphere's incoming solar energy over the year, as opposed to looking at the northern hemisphere temperature averages separate from the southern hemispheres temperatures averages.
    Never is a long time.
    Um, that nice graph there, ah... you do know that CO2 levels only rose to high enough levels to, even theoretically, affect climate around 1960? So that early 20th warming you see, what caused that? How do we know that whatever it was isn't still the primary driver of the warming oceans? And yes, I know there are various papers that attempt a climate recipe with a little sprinkle of aerosols here, and little touch of volcanic influence there with some ENSO attribution whisked in until it's light and fluffy that "explains" the 20th century climate fluctuations but they are often contradictory and in no way highly convincing. The only reasonable thing to say is that CO2 should, probably, make things a little warmer than they would otherwise be. It might still be colder by the end of the century and it might all also be better for the biosphere if it is a bit warmer. Climate science is currently a child being asked to do an adults work by people with a political agenda. I'm not worried overly by the science, it will get there. It those agenda wielding, narrative building alliances of self-interested con-artists that I'm worried about.

    car2nwallaby
    Translation: Don't waste your keystrokes on me.  I only believe science when it conforms to my pre-formed, politically-shaped opinions, and otherwise it's all just a vast conspiracy.
    Hurricane Hysteria... I was wondering when the Extreme Weather bandwagon woud start.

    Can We Link Hurricane Sandy to Climate Change?
    http://blogs.smithsonianmag.com/science/2012/10/can-we-link-hurricane-sa...

    Vicious ocean storms are nothing new. Look into the Grote Mandrenke which reshaped the coastline of Western Europe and killed tens of thousands. If that exact storm replayed now, it would be taken as evidence of "climate change," but what it would really evidence is a chaotic, nonlinear system that kicks out an unbelievably strong storm from time to time. The U.S. is currently experiencing the longest stretch of days between major landfalling hurricanes. The last one to strike U.S. shores was Wilma, in 2005.

    car2nwallaby
    No storm is "caused" by any one thing.  You're exactly right that weather is a chaotic, nonlinear system and Sandy or something like it would have happened even without climate change.  But that's not my point.  The point is that the factors that helped transform Sandy from a hurricane to a superstorm – warmer oceans and a kinked jet stream – are exactly those that we expect more of with climate change.
    The last one to strike U.S. shores was Wilma, in 2005.
    Not central to my point, but I think the victims of Ike (2008), and Irene (2011) might disagree.
    "The last one to strike U.S. shores was Wilma, in 2005."
    I guess you forgot about Gustav, Ike, and Irene. Maybe even Ernesto depending on its status at landfall.

    The hurricane Sandy is not the strongest this season and actually it is quite mediocre tropical storm. So the entire story is just because by coincidence it landed in New York ... so the entire story is interesting mainly for the social scientists and not so interesting for the atmospheric science ...
    Also- the people that claim any connection between a single weather event (like a hurricane) and the climate change (no mater if it is anthropogenic or not) must spend some time to read the definition of climate- the climate is by definition a statistical ensemble so any single event cannot be connected to the climate change (unless we speak about 30 years mean frequencies of tropical cyclons going north of some latitude) because it is WEATHER and not CLIMATE and especially if this event is possible in a stable or even cooling climate, any claim about this single event and some climate forcing is a pure speculation and nothing more. I don't think that anyone with an education in atmospheric physics and/or physical oceanography will make such bold and stupid and unscientific claims.
    Want to connect something to the climate change- speak about frequencies and not single mediocre events.

    Hank
    I have made that case also.  Neither this nor Katrina were even in the top 20 hurricanes of the last hundred years but they are #1 and #2 for political opportunism (not by Robert - in most other science media, though) - . Meanwhile, at the same time, Tropical Storm Son-Tinh has killed more people. Except that is in Asia, where science media can't use a hurricane against a presidential contender.

    If media people were really about concerned climate, or human suffering, and not an election, this would be a nor'easter storm that hit some parts of NYC hard and not others.
    car2nwallaby
    You're absolutely correct: we can't draw climate conclusions from one weather event.  To reiterate:
    Now, it is certainly true that we still don't completely understand hurricanes.  It is true that models are not perfect.  It is true that Hurricane Sandy could have happened even without climate change.  It is true that climate change doesn't "cause" an event, just like doping alone won't win you the Tour de France.  And, as always, it is true that we should not draw conclusions from a single event.
    The point here was to consider how predicted trends will affect hurricanes in the future.  It is difficult to dispute that many of the factors that made Sandy so powerful are exactly those that are getting worse with climate change: warmer ocean temperatures, rising sea levels, weakening jet stream.  Combine that with both recent modeling papers and historical studies cited above, and you get cause for concern.

    The hurricane Sandy is not the strongest this season and actually it is quite mediocre tropical storm. So the entire story is just because by coincidence it landed in New York
    Here you're only partly right.  True, Sandy had only Category 1 winds.  But her barometric pressure – another strength indicator – broke records and she was the second largest storm ever recorded in the Atlantic, all despite being rather far North and nearly into November.  Rather impressive for a "mediocre" storm, although perhaps she is getting an inordinate amount of media attention because of whom she affected.  But humans are a visceral bunch.  Scientists like you and me are trained to interpret statistics and dry statements like "We detect a statistically significant increasing trend in the number of moderately large surge index events since 1923." (Grinsted et al. 2012 PNAS)  As humans, however, in order to care we need translations into examples we can understand.  It is not false to say climate change will exacerbate the same conditions that fed Sandy.  Or, for the Grinsted paper's example: "We estimate that warm years have been associated with twice as many Katrina-magnitude events compared with cold years in the global average surface temperature record."