NEW YORK CITY—Here is how climate change could shut down a city: On the morning of August 8, 2007, a thunderstorm paralyzed the largest rail transit system in the U.S.—New York City's subway—during morning rush hour. Flash floods deposited more than 7,000 kilograms of dirt and debris on tracks that stretch more than 1,350 kilometers and carry 1.5 billion passengers annually. A December 1992 storm had a similar impact, including flooding portions of Lower Manhattan and the East River Drive.

Such powerful storms are exactly what scientists predict to become more frequent as the climate changes. In fact, the New York City Panel on Climate Change (NPCC), co-chaired by NASA climate modeler Cynthia Rosenzweig, predicts a 5 to 10 percent increase in the mean precipitation around New York City by 2080—the bulk of that in extreme precipitation events that deliver a large amount of rainfall in a short span.

At the same time, the panel predicts a temperature rise of 2 to 4 degrees Celsius from the current average temperature of 13 degrees C by 2100. "You need vents to get hot air out of the [subway] system, especially if we are going to have hotter weather," says Adam Freed, acting director of the city's Office of Long-Term Planning and Sustainability. But, he adds, "open grates increase the risk of flooding."

Issues like that make adapting to climate change a tricky balancing act for this city government and others, and shoring up infrastructure such as New York's subway lines will be the work of decades. In the meantime, the city has already planted more than 322,000 trees as part of its MillionTreesNYC initiative as well as converted 25 percent of the city's taxi fleet to more fuel-efficient vehicles, such as hybrids.

And the city purchased on April 8 more than 11,500 hectares of additional land upstate in its watershed in an effort to ensure its water supply, which could be impacted by the droughts and unusual precipitation events that climate change brings, potentially fouling drinking water. Officials also are fighting to keep that land free from drilling for natural gas, which can contaminate groundwater.

New York City is not alone in attempting to address climate change, of course. Chicago has attempted to reduce energy use in buildings by encouraging green roofs—planted gardens on rooftops. Green roofs, which diminish the heat island effect, could also help forestall an expected increase in deadly heat waves such as the one that killed 700 people there in 1995. King County, which comprises the Seattle metro area, in Washington State aims to reduce its greenhouse gas emissions by 80 percent from 2007 levels by 2050. Abroad, efforts range from London's attempts to stem the rising tide of the Thames River with flood barriers to an effort by the (relatively) small city of Rizhao, China, to become carbon neutral.

Solar solution
Back in the city that never sleeps, the urban landscape offers roughly 150 million square meters of rooftop. Much of that roofing is black tar, baking under the summer sun, cracking in winter, and generally contributing to the so-called urban heat island effect that compounds the warming impact of climate change. To seed an alternative future, Mayor Michael Bloomberg's office announced the creation of three "solar empowerment zones" on June 8.

The three zones—Brooklyn's downtown and Greenpoint neighborhoods as well as Staten Island's eastern shore—were chosen both for their expansive rooftop acreage and for an electricity use profile that peaks during the day, when the maximum amount of power can be produced from rooftop photovoltaic panels. The train yards in Coney Island, Brooklyn, already use the sun's heat to warm water used to wash subway cars.

"That came out of [the question]: 'Where are the load pockets in the city that need additional assistance to reduce demand?' Then we target resources to that area to put off more costly infrastructure upgrades," Freed says. "It helps increase resilience."

The efforts to bring solar power to New York, along with the tree-planting, fuel-efficient taxis and watershed efforts, are all part of so-called PlaNYC—an effort to adapt the city to the realities of global warming and other challenges by 2030.

As part of that PlaNYC effort, kicked off April 22, 2007, the city convened a panel of experts to assess the risks posed by climate change. The number-one risk, according to a report issued this past December: infrastructure failures—from a shutdown of the power grid, as occurred in the 2003 blackout, to a degradation of the city's water quality.

"You're looking at a city that could have its infrastructure compromised for periods of time by these climate change impacts," says Steven Cohen, executive director of The Earth Institute at Columbia University, which advised the Bloomberg administration on PlaNYC and continues to assist the effort. "The question is: 'What can you do to prepare for that?'"

It's electric
Mitigating New York City's contribution to the greenhouse gas emissions causing global climate change is another part of the PlaNYC strategy. But it is a tricky balance to strike. On the one hand, abundant natural gas has been discovered in the Marcellus Shale Formation beneath New York State, and burning it rather than coal to produce electricity results in 40 percent fewer emissions of carbon dioxide—the primary greenhouse gas causing climate change. On the other, such drilling could foul the municipal water supply.

The region's only large-scale, local low-emission source of electricity—the Indian Point nuclear power plant that provides the single largest portion of New York City's electricity—faces intense local opposition and may be shut down by New York State's efforts to control how it uses cooling water. With or without this power plant—and the local natural gas—the city hopes to reduce its emissions of CO2 by 30 percent below 2007 levels by 2030. The city government itself aims to reach that same target by 2017.

Moving to distributed generation, such as the rooftop solar power initiative, may help with that. But, more importantly, the city is attempting to reduce its overall electricity demand. "In Manhattan, there is a 2,500-megawatt-per-square mile demand," electrical engineer Reza Ghafurian of Consolidated Edison, the city's power utility, explained at a smart grid event at New York University in February. The city hopes to reduce that through new energy audits and efficiency standards.

After all, 85 percent of the buildings that will be weathering a changed climate in 2030 already exist, according to Freed. And "buildings represent 75 percent of emissions in the city," he adds. That means that retrofitting older multiunit apartment buildings and office towers with everything from better windows to increased insulation is more important for reducing emissions and improving resilience than building new ultra-green buildings. Says The Earth Institute's Cohen: "If the population is going up but energy use is not, that's a positive sign….New York City is already the most energy-efficient place in America, and I think it can become even more energy efficient."

Freed adds: "We are making sure that changes that are necessary are part of our codes and standards, so building resilience is not optional." Fostering such resilience will be the key to adapting to climate change, he says. Just as the city does not attempt to stop a snowstorm but instead prepares for its aftermath, New York also must plan how it will come through an increase in extreme weather events, whether heat wave or flood.

Regional impact
Whereas other cities plan for climate change, New York may be alone in having at least some estimates for its local impacts, thanks to a relatively new and imprecise modeling effort. That effort is imprecise because the computer models for global climate change typically employ grid cells larger than the city itself. Nevertheless, in addition to the temperature and precipitation changes, the NPCC predicts sea level rise of at least 30 centimeters (and as much as 140 centimeters) by 2100.

"This is a coastal city," Cohen notes, with at least 965 kilometers of coastline and an average height above sea level of roughly five meters. Much of New York's critical infrastructure—from power plants to marine transfer stations for garbage—lies on the waterline. "We need to—and can—figure out ways to operate [coastal infrastructure] with an acceptable level of risk," Freed says.

A mayoral task force of 40 government agencies and other stakeholders is currently evaluating what the estimates for sea-level rise and other climate change risks will ultimately mean for New York City, particularly for critical infrastructure like the water supply, in order to prioritize upgrades. "You have to be constantly investing in infrastructure and thinking about vulnerabilities as well as new technologies," Cohen says. "Concern for climate change helps you do that."

Already, efforts have begun, such as raising the generators as well as installing flood doors and other barriers, at a wastewater treatment plant in the Rockaways, Queens, that is currently prone to flooding. "When the waters recede we can flip the proverbial switch and only temporarily shut down," Freed notes.

The NPCC, for its part, stresses such flexible adaptation in any core infrastructure plans. An effective response to climate change, the panel wrote in its December 2009 assessment, promotes "strategies that can evolve through time as climate risk assessment, evaluation of adaptation strategies, and monitoring continues."

Of course the ultimate flexible adaptation will mean updating the plan to deal with a continuing climate of change, in both the political and physical realms. The first revision of PlaNYC is due April 22, 2011. "You can't actually climate-proof a city," Freed says. But "the benefits of the things that make sense to do today greatly increase as our climate changes."

21 Comments

1. 1. Soccerdad 09:53 PM 6/16/10

   Wow - 5 to 10% more precipitation. That's real catastrophic stuff.
   
   And this: "You need vents to get hot air out of the [subway] system, especially if we are going to have hotter weather. But, open grates increase the risk of flooding."
   
   I admit this is a real tough one. Nearly insurmountable. Let's see - maybe put some roofs over the vents?

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2. 2. cocoloco 11:38 PM 6/16/10

   I guess we have never had floods, or tornadoes, or hurricanes before. Maybe we have never had ice ages either. Narcissistic people appear to believe that everything revolves around them, without volcanoes like the one in Iceland that pour out as much CO2 in one week as human beings generate in a year, their fondest hope is that no one will comprehend enough chemistry to question the stupidity of global warming. Of course, we can lie about science since most liberal Americans no longer can decipher the difference.

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3. 3. gervster 08:47 AM 6/17/10

   I think you drastically underestimate what 5-10% more precipitation brings to the table. At current rainfall rates, an extra 10% would add about 3 cubic miles of water to the city. That is catastrophic, and presents a serious problem to current drainage infrastructure. Now, imagine all that rainfaill coming in huge concentrated bursts, as the article suggests, rather than prolonged rains and you really have a problem. Seriously, what do you do Soccerdad?

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4. 4. Jürgen Hubert 12:35 PM 6/17/10

   "Narcissistic people appear to believe that everything revolves around them, without volcanoes like the one in Iceland that pour out as much CO2 in one week as human beings generate in a year,"
   
   Actually, _less_ CO2 was emitted during that period because the increased CO2 from the Icelandic volcano was more than compensated for all those European plane flights that were canceled.
   
   http://www.informationisbeautiful.net/2010/planes-or-volcano/

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5. 5. ND3G 01:23 PM 6/17/10

   I love reading Sciam. The articles are great and all but what I really enjoy is reading the nonsense posted by Soccerdad, cocoloco and their like.
   
   I would almost be comical if it were not so very pathetic.

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6. 6. Soccerdad 03:03 PM 6/17/10

   ND3G, If you want nonsense, then read the article. They turn a bit of conjecture of a mild increase in rainfall, and further speculate that there will be more large rainfall events over the next 70 years or so and translate that into some big disaster.
   
   Oh no! We only have 70 years to adapt to the theoretical incremental rainfall increase! Time to panic!
   
   And by the way gervster - I am Chemical Engineer by training, having graduated first in my class at a top engineering school. I work in finance, having graduated with an MBA, first in my class there as well. How about you?
   
   In real world engineering systems - like drainage from a city - 5 or 10% difference is noise which is barely discernable.

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7. 7. krab1017 10:49 PM 6/17/10

   The emissions from volcanoes do not actually increase the temperature. Every single person who contradicts global warming brings up volcanic activity. Check any research you want, but volcanoes typically cool the earth. That fact can also depend on how much sulfur is released from the volcano. Each eruption is different. Check Mt. Pinatubo. It really aggravates me at the ignorance of your "climate specialists" who spew your propaganda on scientific reports. Science is not biased; you are. Comment on a blog or something where your OPINION matters.
   
   In regards to the comments about fearing a little bit of rain... You miss the point. I cannot fathom how you can go against such a huge consensus of science. If the warnings were not dire, New York would not be addressing them. The skeptics are not climate scientists, mayors of their cities, or anyone with any relevant knowledge of the subject-matter.

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8. 8. krab1017 10:59 PM 6/17/10

   The emissions from volcanoes do not actually increase the temperature. Every single person who contradicts global warming brings up volcanic activity. Check any research you want, but volcanoes typically cool the earth. That fact can also depend on how much sulfur is released from the volcano. Each eruption is different. Check Mt. Pinatubo. It really aggravates me at the ignorance of you "climate specialists" who spew your propaganda on scientific reports. Science is not biased; you are. Comment on a blog or something where your OPINION matters.
   
   In regards to the comments about fearing a little bit of rain... You miss the point. I cannot fathom how you can go against such a huge consensus of science. If the warnings were not dire, New York would not be addressing them. The most powerful and economically influential city in the world is adopting policies to address climate change. Get it?

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9. 9. ennui 12:51 AM 6/18/10

   Ajax, a town in Ontario, was during the war chosen as the best place to put an ammunition plant, as it had for many years never a tornado, thunderstorm or earthquake.
   One day I measured the polarity of the ground, it was positive.
   Six miles North of Ajax the ground became negative. They had the tornadoes.
   A small invention of mine can make the ground positive over a selected area. That area will be safe.
   In the future someone in the firehall might , when tornadoes are predicted, activate the units to slowly polarize the ground in tornado -prone places like Oklahama.
   Maybe some insurance company would be interested.
   That same invention can also be used to delay an earthquake, to give people the chance to evacuate.
   

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10. 10. DrAlexC in reply to Soccerdad 01:52 AM 6/18/10

    NY subway cars use resistive braking, rather than regeneration, as many worldwide electric railways & Priuses do. So, better design there is long overdue anyway (having lived in NYC & the subway).

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11. 11. Jürgen Hubert 05:49 AM 6/18/10

    "And by the way gervster - I am Chemical Engineer by training, having graduated first in my class at a top engineering school. I work in finance, having graduated with an MBA, first in my class there as well. How about you?"
    
    Well, if we are pulling rank here, I am a physicist by training and have a PhD in Computational Materials Engineering.
    
    And based on my experiences, finding dubious statistical tricks, gross misrepresentations of the facts, or even outright lies is what happens more often than not when I research the claims of self-proclaimed "global warming skeptics".

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12. 12. gervster 08:06 AM 6/18/10

    I think my post got booted by Soccerdad, which is too bad because that anonymous "top engineering school" was priceless. Ahh, but in all seriousness, it's nice to see that some fellow engineers are following the site. I for one am actually - sorry Soccerdad, but you're clearly a fake - working on a combined MEng - Environmental, MBA Natural Resources program.

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13. 13. ND3G 09:25 AM 6/18/10

    Soccerdad wrote: I am Chemical Engineer by training, having graduated first in my class at a top engineering school. I work in finance, having graduated with an MBA, first in my class there as well. How about you?
    
    And I have a masters degree in Mechanical Engineer from the University of Toronto and an MBA from Schulich. What of it? None of this changes the fact that everything you type is pure garbage.
    

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14. 14. Soccerdad 09:27 AM 6/18/10

    Jurgen - I didn't realize you were involved in the conversation. Gervester asked me what I did. I told him and he hasn't really answered back with any specifics.
    
    I guess you guys just go with the flow and don't really think for yourselves. If we had been having this discussion in the 1970's, you would have been predicting mass famine, running out of oil and another ice age in the early 2000's.
    
    5 - 10% more precipitation causing massive problems? It varies much more year to year.

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15. 15. gervster 09:09 AM 6/21/10

    We're not concerned about the normal variance of weather here, that's always going to be a given. Instead, as the article suggests, the average precipitation will be jumping up 5-10% - on top of the regular varying nature of weather. Further problematic is the fact that they're predicting more weather anomalies like highly concentrated, heavy rains. Believe it or not, that makes a big difference us engineers designing water draining systems. As mentioned before, 3 cubic miles is no drop in the hat.

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16. 16. Jimstehrman 12:52 PM 6/21/10

    Transposing this conversation to the 70's is not a valid point at all. The advances in computational horsepower and climate science have given us (dissenters included) many more tools to investigate this phenomena. You cannot discredit the efforts of others when you have not given an effort yourself. Also, taking the counter point of an argument does not qualify you as a free thinker. I see no reason or fact on your side and merely your unsubstantiated word against the efforts of others. We are more than willing to consider the views of dissenters, if they cared to get their hands dirty and come up with some cohesive fact base, rather than disagree for the sake of conjecture.

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17. 17. jwinston 03:35 PM 6/24/10

    10% increase may be within the normal fluctuation on a yearly basis, but there still will be that yearly fluctuation on top of the overall increase. If the normal is 10% higher, and there is an additional 10% fluctuation, that is a 21% increase, and that could be catastrophic.

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18. 18. Nicholasunik 01:50 PM 7/1/10

    One way to reduce heating of the New York Environment would be to get people to lose weight and get fitter so they don't need so much air conditioning.

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19. 19. RevenuefromRooftops 07:55 AM 7/4/10

    Best strategy to adapt to climate change is if building owners aren't going to get solar or green roofs, they can list their rooftops as sites for solar energy, wind energy or urban farming at www.seglet.com. Becoming a site for distributed food or distributed energy, building owners can get additional revenue and go green. It's a win-win for everyone!

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20. 20. thevillagegeek in reply to ennui 08:02 PM 7/20/11

    You present no dates, no numbers, no definitions, no documentation, no evidence. Even if your claim is true, correlation is not causation. We have your extraordinary claim. Where is your extraordinary evidence?

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21. 21. DieterHH 07:05 PM 12/2/11

    Soccerdad: .".. In real world engineering systems - like drainage from a city - 5 or 10% difference is noise which is barely discernable. .."..... Exactly ! Engineered systems always have significant safety margins to ensure the design computations are'nt on the hairy edge of failure, and to accomodate real world "live" load spike events. +/- 5-10% is noise. The "Green" and global warming crowd do themselves a disservice by propagandizing superficial diseaster scenarios and so called technical solutions which have no basis in terms of energy physics and economic context. And the superficial focus on CO2 reduction diverts attention from much more effective solutions such as general improvements in energy efficiency, gas .... or more pervasive modern nuclear plants. Ignored entirely seems to be the ongong overpopulation elephant in the room, and its direct impact on already marginal eco systems. As for myself - global warming = precautionary principle so don't waste, and I would never consider living in or near any region of metropolitan sprawl since the urban termites are their own worst enemies.

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