Climate Change in New York City

A Teacher’s Guide and Classroom Resource

NYC DEP Climate Change Module

Overview of Climate Change

in New York City

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Weather vs. Climate

“Weather is what you get; climate is what you expect.”

Climate describes
weather patterns
over a longer term

Weather describes
current and near-
term conditions

Source: NOAA

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What is the difference between climate variability and climate change?

Climate variability
occurs independent
of climate change.

Climate variability is
generally measured
over 30 years of
atmospheric variables.

“Seasonal variations and multi-year cycles (for example, the El Niño Southern Oscillation) that produce warm, cool, wet, or dry periods across different regions are a
natural part of climate variability. They do not represent climate change.”

-NOAA, Climate.gov

How do we know the global

climate is changing?

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The Greenhouse Effect

Scientists have understood this pattern for over a century.

Source: NASA

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The contribution of excess greenhouse gases like CO2 cause the Earth to warm

Source: NASA

Humans are tipping the balance.

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Where are these emissions coming from?

Source: IPCC (2014)

Based on 2010 global
statistics, emissions from
electricity, heat production,
agriculture, forestry and other
land use account for
approximately half of
greenhouse gas emissions
globally.

Emissions from “Industry”:
“Greenhouse gas emissions from
industry primarily involve fossil fuels
burned on site at facilities for energy.”

Emissions from “Other Energy”:
Includes “all emissions from the Energy
sector which are not directly associated
with electricity or heat production, such
as fuel extraction, refining, processing,
and transportation.”

-EPA Global Greenhouse Gas Emissions Data

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New York City Emissions

NYC’s GHG emissions come almost entirely from the combustion of fossil fuels to
provide energy. However, this energy is delivered in many different forms.

NYC Mayors Office of Sustainability

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Breakdown of New York City Emissions By Source

NYC Mayors Office of Sustainability

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Carbon dioxide (CO2) emissions from fossil fuel combustion and industrialization is
the primary cause of climate change.

Breakdown of GHG Emissions

•We can’t forget about the other GHGs

•Different greenhouse gases are linked to different activities

•For example, methane is most closely linked to livestock

U.S. vs. Global GHG Emissions

Total emissions in the U.S. in 2017 = 6,457
million metric tons of CO2 equivalent

Source: IPCC (2014)

Source: EPA (2017)

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Methane

Impacts of Methane and
Livestock

Methane (CH4) has a higher global
warming potential (GWP) than carbon
dioxide (CO2).

According to the EPA:

•CO2 has a GWP of 1, and remains
in the climate system for a very long
time

•CH4 is estimated to have a GWP of
28–36, and remains in the climate
system for over 100 years

•CH4 emitted today lasts about a
decade on average, which is much
less time than CO2

•CH4 also absorbs much more
energy than CO2

Infographic: LiveScience 2015

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2016: Warmest year on record, 1.78°F above the 20th century average

While we have year-to-year

fluctuations in climate, the long-term

trend is warming.

Source: NOAA

Global Temperature
Ranking, 1880-2018

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2016

2

2015

3

2017

4

2018

5

2014

6

2010

7

2007

8

2013

9

1998

10

2006

11

2004

12

2002

13

2005

14

2011

15

2009

16

2012

17

2003

18

1999

19

2008

20

2000

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Ten Indicators of a Warming World

These indicators are embedded into global climate models.

Source: National Climate Assessment, 2014

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Understanding Anthropogenic Forces

Models can reproduce the climate with and without added CO2.

Source: National Climate Assessment, 2014

Are we seeing climate

change today?

Observed Trends

Source: National Climate Assessment, 2014

Changes in Heavy Precipitation Events
Northeast

Temperatures

are rising

Increasing populations in many
US Coastal Watershed Counties

(1970-2010)

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Observed temperature change in the

United States over 1991-2012 compared

to the 1901-1960 average.

Percent increases in the amount of
precipitation falling in very heavy events
(defined as the heaviest 1% of all daily events)
from 1958 to 2012.

Average vs. Extreme Events

Shifts in average conditions lead to more frequent extreme events.

Climate Extremes Worldwide

Cyclone Nargis in Myanmar, 2008

(Neryl Lewis, RRT)

Famine in Somalia, 2017

(New York Times)

Extreme Heat Wave in India, 2015

(CNN)
Severe flooding in Pakistan, 2015

(Reuters/London)

A warmer atmosphere
can hold more water.

Extreme rainfall and
drought are projected to
increase globally.

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Source: IPCC AR5 WG2 Ch. 3, 2014

Projected change in flood hazard in the 2080s

Changes in Floods and Drought

There is wide uncertainty in the models about the direction of change.

Examining Our Personal Actions

Our daily actions have significant environmental
impacts, which are measured as our ecological
footprints or carbon footprints

Ecological Footprint: The measurement of our
impact on the Earth based on the activities we do
every day

Carbon Footprint: The amount of carbon dioxide
that is emitted by the activities we do every day
and the fossil fuels associated with them

Factors that inform our footprint:

•Water use

•Diet

•Travel

•Consumption habits

•Energy use

Source: CEA Energy

How will climate change

affect New York City?

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•New York City Panel on Climate Change (NPCC)
convened in August 2008 as a collaboration of
leading climate and social scientists and risk
management experts who work to identify climate
risks facing New York City and guide OneNYC
policies

•In 2010, the Panel produced the first full report
detailing a set of climate projections specific to
the New York City region, published by the New
York Academy of Sciences

•New York City Codified NPCC in August 2012 with
Local Law 42, requiring regular climate science
updates to the Mayor’s Office of Resiliency

•Research is used to help decision-makers plan
for resiliency according to the climate risks that are
specific to New York City

•NPCC’s most recent publication is the 2019 Special
Issue: Advancing Tools and Methods for Flexible
Adaptation Pathways and Science Policy Integration

New York City Panel on Climate Change

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* Observations made in Central Park.

Temperature*
Mean annual temperature has increased
at a rate of 0.3°F per decade (total of
3.4°F).

Source: NPCC, 2019

Sea Level
Sea level rise in New York City has
averaged 1.2 inches per decade (total of
1.1 feet), nearly twice the observed global
rate over a similar time period.

Precipitation*
Mean annual precipitation has increased
~0.8 inches per decade (total of 8 inches).

Year-to-year (and multi-year) variability of
precipitation has become more
pronounced, especially since the 1970s.

NPCC Observed Climate Trends (1900 – 2013)

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* Middle range (25th to 75th percentile) of model-based projections.

Mean annual temperatures to
increase

– 4.1 to 5.7°F* by the 2050s
– 5.3 to 8.8°F* by the 2080s

Heat waves: Triple by 2080s from
2 to 6 per year

Hot days above 90⁰: Triple by
2050s from 18 to 57 days

NPCC Climate Projections – Heat

Source: NPCC, 2015

Seniors Aged 65+ Without

Air Conditioning

Heat Vulnerability in NYC

Depicted in the darker purple are the portions of NYC’s
population that are most vulnerable to high
temperatures, by neighborhood.

Source: OneNYC

Source: NOAA Climate

Heat vulnerability is determined by both
social factors and physical features of
neighborhoods.

The Urban Heat Island Effect

•We experience higher temperatures
in big cities, this is due to the Urban
Heat Island Effect.

•Urban Heat Island Effect: “a
regional elevation in air temperature
that represents the difference
between air temperatures in urban
and built up areas and nearby rural
areas.” -The Mayor’s Office of Resiliency

•“The annual mean air temperature of
a city with 1 million people or more
can be 1.8–5.4°F (1–3°C) warmer
than its surroundings. In the evening,
the difference can be as high as 22°F
(12°C).” -EPA Heat Island Effect

Source: EPA

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* Middle range (25th to 75th percentile) of model-based projections.

Mean annual precipitation is projected to increase

– 4 to 11 percent* by the 2050s
– 5 to 13 percent* by the 2080s

NPCC Climate Projections – Rain

Source: NPCC, 2015

Warmer temperatures cause more moisture in the air, which leads to significant shifts in precipitation.

Heavy rainfall events are often associated with
relatively brief but intense warm season events
(e.g., summer thunderstorms). Heavy rainfall is
projected to increase in New York City.

Flooding transportation networks

•Roadways

•Subway stations

•Railways

•Airport runways

Overwhelming sewer systems

•Combined Sewer Overflows (CSOs)

•Drainage capacity

•Harbor water quality

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NY State record flash flooding occurred on August
12-13, 2014 in Islip, NY where 13.57 inches of rain
fell in one day (Long Island Patch, 2014)

Heavy rains caused flooding on the 86th Street
Transverse on July 7, 2017

Heavy Rainfall Events aka “Cloudbursts”

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* Middle range (25th to 75th percentile) of model-based projections.

Sea level is expected to rise

– 11 to 21 inches* by the 2050s
– 18 to 39 inches* by the 2080s
– 6 feet by 2100 (high

estimate)

Projected sea level changes
alone would increase the
frequency and intensity of
coastal flooding (absent any
change in storms themselves)

NPCC Climate Projections – Sea Level Rise

Source: NPCC, 2019

Map showing the difference between water levels for 90thpercentile SLR in 2100

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* Middle range (25th to 75th percentile) of model-based projections.

Sea level is expected to rise

– 11 to 21 inches* by the 2050s
– 18 to 39 inches* by the 2080s
– 6 feet by 2100 (high

estimate)

Projected sea level changes
alone would increase the
frequency and intensity of
coastal flooding (absent any
change in storms themselves)

Sea Level Rise

Source: U.S. Climate Resilience Toolkit

As a coastal city, NYC is uniquely vulnerable to sea level rise and storm surge.

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.

100-year flood map developed using the static approach

• For the 100-year flood, the high-

estimate sea level rise by 2100 roughly
doubles the affected area compared to
the December 2013 FEMA Preliminary
Flood Insurance Rate Maps (FIRMs).

• For the 500-year flood, the high-

estimate sea level rise by 2100
increases the affected area by 50%
compared to the December 2013 FEMA
FIRMs 500-year flood area.

• Queens is the borough with the most

land area at risk of future coastal
flooding due to sea level rise, followed
by Brooklyn, Staten Island, Bronx, and
Manhattan.

• "100-year flood" does not refer to a flood

that occurs "once every 100 years,” it
actually refers to the size of the flood
itself and the percent probability of it
occurring in any given year (e.g. 1%).

Source: NPCC, 2019

Coastal Flooding and Climate Change

•Nearly 10 million people are served by
the NYC water supply system

•All of the City’s 14 wastewater
resource recovery facilities will, by
2050, have at least some of their
equipment located below the Base

Flood Elevation.

•Of the City’s 96 sewage pumping
stations, 58 are located in the 100-
year floodplain indicated in the Federal
Emergency Management Agency
(FEMA) Preliminary Flood Insurance
Rate Maps.

•Base Flood Elevation refers to the
“height that flood waters are expected to
reach in a high risk area.” here.

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Sources: NYC 2018 Drinking Water Supply and Quality Report, and NYC Wastewater Resiliency Plan

Wastewater facilities at-risk of storm surge inundation

Source: FEMA; CUNY Institute for Sustainable Cities

Vulnerability of Water Resources

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Source: PlaNYC, 2013

Hurricane Sandy (left)
compared to Hurricane
Katrina (right). Source:
NASA.

October 29, 2012

August 29, 2005

Hurricane Sandy was the Tipping Point

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Source: PlaNYC, 2013

Hurricane Sandy (left)
compared to Hurricane
Katrina (right). Source:
NASA.

Lessons from Sandy

•New York City is vulnerable to the impacts of
climate change from sea level rise and coastal
storms. Extreme weather events can present
unforeseen impacts that must be included in
future resiliency planning.

•The impacts from climate change will be
distributed unevenly across City neighborhoods
as a result of land-use, economic status, age, and
exposure.

•The cascading impacts from extreme events
on interdependent infrastructure systems
highlights the need to account for
interconnected vulnerabilities in New York City.

•New York City’s history of climate action was
critical in the Hurricane Sandy rebuilding
process.

•Utilizing the co-generated science created by
the NPCC to understand the specific local risks
that climate change poses to the metropolitan
region, New York City is already engaging in
planning for resiliency over the coming century.

Conclusions

•We know climate change is happening based on observed evidence.

•Scientists project future climate changes by using computer models.

•Climate change is affecting New York City through changes in temperature,
precipitation, sea level rise, and extreme weather events.

•New York City is leading the effort to mitigate and adapt to climate change.

•We, as individuals and as a city, need to take action!

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Source: NYC DEM Clean and Renewable Energy

Source: Eagle Street Rooftop Farm

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Taking Action: What can we do to help?

•Get involved in the global student climate action
movement

•Learn about your water footprint and water conservation

•Help plant school gardens and maintain green spaces

•Dispose of waste and recyclables properly, reduce litter

•Conserve energy

•Learn about your carbon footprint and resource
conservation

•Learn about your personal food consumption and ways
to reduce your impact

•Team up with local environmental groups

•Get to know community leaders and register to vote

•Learn about internship and career opportunities

Greta Thunberg, 16 year old Swedish climate activist calls for global student climate strikes, “Fridays For Future” (Source: TEDx)