Copyright © 2018, California History-Social Science Project, Regents of the University of California, Davis Current Context, October12, 2018 Edition, http://chssp.ucdavis.edu—Page 1

by Shelley Brooks, Ph.D.

Living along the coast can bring great joys and great perils.

Just recently, Hurricane Michael swept through the southeast

spreading destruction from winds and flooding. Climate

change is increasing this likelihood of flooding during storms in

two ways: 1) by increasing the level of the oceans and there-

fore tidal surges, and 2) because warmer air holds more mois-

ture and produces more rain. As an M.I.T. professor explains,

“There is strong consensus among scientists who study hurri-

canes and climate that warming temperatures should make

more intense hurricanes possible.”

Around the United States and throughout the world, approxi-

mately 40% of the population lives in what is termed the

coastal zone. This population trend is only accelerating, as mi-

gration to the coasts continues to outstrip other regions. The

coasts are not only the sites of recreation and relaxation, but

also vibrant economic opportunities. In an era of climate

change, the challenge now facing all of us – whether we live by

a coast or not – is that warming temperatures are contributing

to sea level rise and putting people, homes, businesses, air-

ports, highways and more at increasing risk of flooding.

Scientists explain that sea level rise is not something that we

can prevent from happening. As the planet warms, ice sheets

and glaciers will diminish in size (and in some cases melt

away), releasing more water into the ocean. Warmer water

temperatures lead to higher ocean levels. Regional ocean cur-

rents and storm surges exacerbate the issue in certain areas.

Eight of the ten largest cities in the world are located by the

coast, meaning that places like New York, Tokyo, Lagos, Mum-

bai, and Rio de Janeiro are grappling with how to protect very

large populations and extensive infrastructure from rising wa-

ters. Meanwhile, small island nations in places like the South

Pacific and the Indian Ocean are particularly at risk of becom-

ing uninhabitable due to rising waters and the related chal-

lenges associated with sea level rise.

While it is difficult for scientists to provide exact numbers for

what we should expect, a recent report estimates that the

global sea level may be twenty-five inches higher by the year

2100. Though scientists acknowledge that sea level rise will

continue well into the future, the United Nations and other

intergovernmental organizations stress the importance of min-

imizing greenhouse gas emissions as a way to minimize the

ocean’s rise. Meanwhile, city planners in many parts of the

world are taking sea level rise into account when making deci-

sions about development so as not to place more people and

buildings in the areas most susceptible to flooding.

This edition of Current Context explains the science behind sea

level rise; provides a brief history of how we came to this

point; examines some of the places and people most at risk;

and considers what can be done about one of the greatest long

-term challenges we face.

Copyright © 2018, California History-Social Science Project, Regents of the University of California, Davis Current Context, October12, 2018 Edition, http://chssp.ucdavis.edu—Page 2

Why is there sea level rise?

While the level of the ocean remained fairly stable for the past 7,000 years or so, it began to rise about 150 years ago due to

industrialization. Burning fossil fuels for energy – to run our cars, heat our homes, power factories – emits greenhouse gases

that help trap heat in the Earth’s atmosphere. We rely on a certain amount of greenhouse gases (some of which occur natural-

ly) to keep the Earth at a temperature that is comfortable enough for people, animals and plants. Too much of these gases,

however, results in an increase in the average temperature around the world, what is often called global warming. Human-

driven changes to the climate lead to rising temperatures that melt ice that has long been present in the Earth’s coldest regions.

These human-driven changes are amplified by natural processes

that make the issue of sea level rise even more challenging:

Melting ice turns into water that flows into the ocean, in-

creasing its volume.

The ocean and the land absorb heat from the sun, unlike ice

which reflects heat. So, when ice in glaciers or icebergs

melts, it exposes more land and ocean water to the sun.

More of the heat is absorbed, thereby warming both the ocean and the land.

The ocean acts as a natural storage site for carbon dioxide. Unfortunately, a warmer ocean cannot store as much carbon

dioxide as a cooler ocean. So, as the ocean warms it releases more carbon dioxide. Carbon dioxide is a greenhouse gas that

contributes to global warming. This warming leads to more melting ice.

Ultimately, a warmer ocean is less dense than a cooler one, which causes the water volume to increase. This contributes to

sea level rise.

B urning fossil fuels for energy –

to run our cars, heat our

homes, power factories –

emits greenhouse gases that help trap

heat in the Earth’s atmosphere.

Copyright © 2018, California History-Social Science Project, Regents of the University of California, Davis Current Context, October12, 2018 Edition, http://chssp.ucdavis.edu—Page 3

Why do so many people live by a coast, and what might the

future hold for the world’s coastal areas?

Historically, people have chosen to live along coastlines be-

cause such places offer clear natural advantages. Relatively

mild climates, and often fertile lands enabled successful agri-

culture. Protein-rich food came from the ocean and rivers. In

addition, trade on a large scale began in these places because

boats were the earliest form of transportation able to move

large quantities of goods. For all of these reasons, coastal and

delta regions have supported large populations for thousands

of years. Moreover, tourism and retirement have only in-

creased the popularity of coastal areas in recent times.

In fact, people are so eager to live along the coast or establish

businesses there that many cities have actually built new land

along coastlines by filling in shallow areas with rock, trash and

other materials. The San Francisco Bay is a good example of

this “infill.” Approximately one-third of the original extent of

the San Francisco Bay has been converted to infill so that the

area covered by water is smaller than it was before the Cali-

fornia gold rush. Meanwhile, the depth of the Bay has become

more shallow. The island of Singapore has increased its size by

22% through infill. Artificial land decreases the space available

for water to flow and therefore exacerbates flooding associat-

ed with sea level rise.

In other areas, land is actually sinking – called subsidence –

because people are drawing out underground water or oil.

The oil-rich Gulf Coast of the southern United States is a place

where the land is sinking, making the impact of sea level rise

even greater. So is the Central Valley of California, where peo-

ple have been pumping underground water for generations in

order to meet water demands in this arid region. As periods of

drought increase as climate change unfolds, people are likely

to rely even more heavily on underground water supplies.

In short, coastal areas tend to hold large populations—

populations that sometimes live on top of artificial land or

land that is slowly sinking. These challenges complicate the

impact of sea level rise upon these popular coastal stretches;

so will population growth. People will not abandon the coasts,

so the goal is to protect current and future structures from

flooding while also working to limit the amount of flooding in

the first place by limiting global warming.

Sea Level Rise and Land Subsidence

Sea level rise

7-12 mm/year

Land subsidence

2-10 mm/year

Scientists estimate that the combination of

subsidence and sea level rise will put at risk

of flooding over one hundred square miles of

the San Francisco Bay Area by 2100.

Copyright © 2018, California History-Social Science Project, Regents of the University of California, Davis Current Context, October12, 2018 Edition, http://chssp.ucdavis.edu—Page 4

What is being done about sea level rise?

Given that there are approximately 150 million people who

now live within three feet of a high tide line along the coast,

and hundreds of millions more who live just above that, sea

level rise is an immediate global threat. Knowledge of this

threat helped lead to the 2015 Paris Agreement on Climate

Change, in which nearly every nation in the world agreed to

do its part to reduce greenhouse gas emissions that contrib-

ute to global warming and sea level rise. The Paris Agreement

set a target of 3.6°F as the maximum increase of average tem-

peratures over pre-industrial averages. Just this month, the

United Nations released a report on the drastic effects that

even a 2.7°F temperature increase will likely have on the plan-

et and its people in the next several decades. Drawing from

thousands of scientific studies, the work of over one hundred

authors, and a review team of more than one thousand scien-

tists, the report warns of the risk of increased flooding, as well

as increased periods of drought, species loss and extinction,

crop loss and more if nations do not take significant steps to

lower emissions.

Leaders of low-lying nations like Tuvalu, an island nation

which sits no more than fourteen feet above sea level, have

taken a lead role in calling for global attention to the climate-

related challenges the world faces — problems that they

played little role in creating. Tuvalu, and many other develop-

ing countries facing serious threats from sea level rise — like

Vietnam, the Bahamas, and Bangladesh — do not have a long

history of industrialization or high

standards of living (multiple car-

households, air travel, and other

energy-consuming choices) that

emit large quantities of carbon

dioxide into the atmosphere.

Nevertheless, these developing

nations experience the same

changing climate as those coun-

tries that drove the industrial rev-

olution, while working with less

advanced infrastructure and

emergency response, and, in gen-

eral, larger poorer populations

living in coastal flood zones.

Word Bank

Carbon dioxide - a greenhouse gas that results from burning fossil fuels

Climate change - long-term and long-lasting changes to Earth’s weather patterns and temperature.

Developing countries- countries that have low levels of in-dustrialization, as well as lower life expectancy, personal income, and education levels than in industrialized nations

Environmental justice - a fair distribution of environmental hazards so that no population bears the greatest burden of industrial pollution, waste sites, etc. Includes giving all peo-ple a voice in deciding development locations and environ-mental laws, regulations and policies.

Global warming - increasing average temperatures on Earth

Greenhouse gas emissions - gases that result from the burning of fossil fuels and trap heat in the atmosphere

Industrialization - transformation of an economy from pro-duction of goods by human and animal labor to production by machines in factories and power plants

Industrial revolution - the transition to mechanical manu-facturing starting in the late 18th century

Infrastructure - the roads, plumbing, sewage, communica-tion network, energy supply, and other facilities and struc-tures that support a society

Subsidence - the sinking or settling of land due to removal of groundwater, oil or natural gas (through pumping, frack-ing, mining)

A road in Tuvalu, an island

nation in the South Pacific.

Copyright © 2018, California History-Social Science Project, Regents of the University of California, Davis Current Context, October12, 2018 Edition, http://chssp.ucdavis.edu—Page 5

In recognition of the particular challenges facing developing

nations, the Green Climate Fund was established in 2010 at a

United Nations convention to help developing nations estab-

lish sustainable energy programs and respond to hardships

posed by climate change. Developed countries—that is, those

countries that have already developed a strong economy at

least in part through industrialization—contribute to the fund

as a form of compensation to developing countries that now

do not have the same options for industrial growth in an era

of concern over climate change. Australia, for one, has

pledged $1 billion in support for such efforts, and recently

provided direct support for the nation of Tuvalu. Tuvaluans

may become part of a growing number of “climate refugees”

- people who are forced to move from their homelands due

to sea level rise, a shortage of fresh water, extreme storms,

and other problems associated with climate change. The

Green Climate Fund aims to provide environmental justice by

funding projects that will help to build protection and resili-

ence among the developing countries and populations most

at risk of climate-related hardships.

California aims to be a world-leader in addressing climate

change through a number of laws and programs that seek to

reduce the state’s carbon footprint, including a carbon cap

and trade program. California prioritizes fuel-efficient vehi-

cles, renewable energy sources like solar and wind, and inno-

vative approaches to limiting industrial, agricultural, and resi-

dential greenhouse gas emissions. With forty million resi-

dents and one of the largest economies in the world, Califor-

nia’s approach is not only important for its impact on the

climate, but it also serves as a good example of how to main-

tain a strong economy while also taking the needs of the en-

vironment into account. California joins many other states

within the U.S., and nations from around the world, in lead-

ing the call for a commitment to reducing greenhouse gas

emissions. Ultimately, a successful global response to climate

change will rely upon individual choices as well as govern-

ment programs. The choices we make in terms of our trans-

portation, our housing, our diet, and more all play a role in

whether we will address sea level rise.

Upsala Glacier in Argentina, which has been melting rapidly in this century. From 2006 to 2010 it lost 40 yards of its length each year.

How do your individual choices impact the environment?

Use this carbon footprint calculator to learn more.

Copyright © 2018, California History-Social Science Project, Regents of the University of California, Davis Current Context, October12, 2018 Edition, http://chssp.ucdavis.edu—Page 6

Mapping the Impact of Sea Level Rise

You may want to use a map from National Oceanic and Atmospheric Administration (NOAA) to locate the cities, coun-

tries, and regions in this mapping exercise. NOAA’s map provides additional information about sea level rise.

Using a world map (you can use this NOAA map: https://coast.noaa.gov/slr/):

Identify and locate the world's ten most populous cities. Where are they in relationship to a coastline?

Identify and locate a few low-lying island nations. How many people live in these countries?

Identify and locate a few areas of the world that are experiencing the worst subsidence (sinking land).

Identify and locate the areas of the world most susceptible to storms that often cause flooding (hurricanes, ty-phoons)

What recommendations would you give to world leaders in order to address sea level rise? Additional activity suggestions:

How is your community likely to be affected by sea level rise? Research what your community, region, or state is doing to

address the changing climate’s impact on your community and environment.

Participate in the international King Tides Project to document evidence of high tides and flooding: http://kingtides.net/participate/join-a-project/

Watch a National Geographic video with Bill Nye to learn more: https://www.youtube.com/watch?v=EtW2rrLHs08

NOAA map of tidal flooding along the U.S. coastline, sometimes called recurrent or nuisance flooding. The red portions are areas

currently subject to tidal flooding due to rising sea level meeting low-lying coastal lands. Annual floods of this sort are five to ten

times more frequent than they were in the 1960s, and scientists predict that areas subject to flooding today will at some point

before long become simply the high-tide line for the ocean.

Copyright © 2018, California History-Social Science Project, Regents of the University of California, Davis Current Context, October12, 2018 Edition, http://chssp.ucdavis.edu—Page 7

A program of CalRecycle’s Office of Education and the Environment, EEI lessons are designed to foster environmental

literacy among California students. Below is a list of units and lessons to support student learning on the topics of indus-

trialization, transportation, and environmental regulations.

1.4.2 On the Move, Lessons 1 “Moving on Land,” 3 “Getting There,” 4 “Ways and Means,” 5 “Short and Long Trips”

2.2.4 California Lands: Then and Now, Lesson 3 “A Growing Population”

5.4.1 Human Settlement and the Natural Regions of the Eastern Seaboard, Lessons 1 “Coast to Coast Connections,” 3 “An Ocean of

Services”

8.6.3 America Grows, Lesson 3 “Across the Sea: U.S. Cities in the 1800s”

8.12.5 Industrialization, Urbanization, and the Conservation Movement, Lessons 2 “The Growth of a City,” 4 “Cities and Natural Systems”

10.3.1 & 10.3.5 Britain Solves a Problem and Creates the Industrial Revolution

10.3.3 Growth of Population, Cities, and Demands, Lessons 1 “Los Angeles on the Move”, 5 “Governments Respond to Managed

Growth”

11.5.7 Mass Production, Marketing, and Consumption in the Roaring Twenties, Lessons 1 “New Inventions Bring New Challenges,” 2

“The Rise of Mass Production,” 3 “A Rise in Mass Consumption,” 5 “Consequences of Consumption”

11.8.6. Postwar Industries and the Emerging Environmental Movement, Lesson 3, “Tracking the Postwar Industrial Boom”

11.9.7 The United States and Mexico: Working Together, Lesson 5 “International Agreements”

11.11.5 Many Voices, Many Visions: Analyzing Contemporary Environmental Issues, Lessons 4 “Roots of Controversy,” 5 “Regulations

and Rights”

12.7.6 (Gov) Making and Implementing Environmental Laws, Lessons 1 “The Responsibilities of Government: Protecting the Environ-

ment and Public Health,” 2 “Government at Work: Cleanup at the Former Long Beach Naval Complex,” 3 “Implementing Public Poli-

cy: Cleaning Up the Sulphur Bank Mercury Mine,” 4 “State Powers and Responsibilities: Taking on Brownfields,” 5 “Thinking ‘Green’:

A New State Approach

12.2.2 & 12.2.7 (Econ) Sustaining Economies and the Earth’s Resources, Lesson 5 “Regulating the Market”

12.3.1 (Econ) Government and the Economy: An Environmental Perspective, Lessons 2 “Economic Benefits and Costs of Environmen-tal Regulation,” 3 “Cap and Trade,” 4 “Fiscal Policy and the Environment,” 5 “Applying Fiscal Policy”

Current Context: A Publication of the California History-Social Science Project

Produced by the California History-Social Science Project (CHSSP), Current Context is a series of instructional materials designed to help students understand current events in historical context. All Current Context materials are copyrighted by the Regents of the University of California, Davis. This issue of Current Context is the tenth in a special series dedicat-ed to helping students understand the connections between environmental literacy and the study of history-social sci-ence, and is funded through the generous support of Ten Strands. To download this issue and others, visit: http://chssp.ucdavis.edu/current-context.

For more information about the CHSSP, visit our website, http://chssp.ucdavis.edu. Headquartered in the Department of History at the University of California, Davis, the CHSSP is one of nine disciplinary networks that make up the California Subject Matter Projects, administered by the University of California, Office of the President.

Image citations: Cover image: https://www.jpl.nasa.gov/news/news.php?feature=6254; Greenhouse Gas Emissions graphic: CHSSP staff: Alexandra Mar-

tinez; San Francisco: https://www.loc.gov/item/2011631173/ photo by Carol Highsmith; Tuvalu: https://commons.wikimedia.org/wiki/

File:Landscape,_Tuvalu,_2011._Photo-_DFAT_(12779525995).jpg; Glacier in Argentina: https://images.nasa.gov/details-GSFC_20171208_Archive_e001486.html;

carbon footprint calculator: https://www3.epa.gov/climatechange//kids/calc/index.html;