​A 2016 Climate Central study revealed that human actions are resulting in rising global sea levels. As a result, some primary concerns are how populations, buildings, infrastructure, land and contamination risks will be affected by these rising sea levels. For Thurston County, there is an increased risk of flooding, especially in the most vulnerable areas that closely line large bodies of water.
 
Thurston County, home to the city of Olympia, rests on the bank of the Puget Sound inlet. A U.S. National Research Council report projected a 9% risk of at least one flood over 4ft occurring sometime between today and 2050 in the Olympia area. By the year 2060, this percentage is projected to rise to 24% before drastically increasing to 62% by the year 2070 with flood levels expected to rise well above 4ft.
 
The frequency and intensity of heavy rain events is also projected to increase according to a 2015 study conducted as part of the Climate Impacts Group’s “State of Knowledge” series that focused on the Puget Sound area. Increased precipitation is directly linked to increasing global air temperatures that will lead to more freshwater inflows into the Puget Sound, particularly during winter months. Additionally, rising air temperatures would increase the likelihood of harmful algal blooms in the ecosystem.
 
While Washington state as a whole is at risk to the effects of climate change, areas such as Thurston county that are near central bodies of water are particularly vulnerable. Rising temperatures and sea levels will directly impact the Puget Sound and its surrounding areas. The effects of climate change will surely have a range of sociological, ecological and economic impacts on Thurston county.

​These projections rely primarily on two tools that are freely accessible online: the “State of Knowledge Report - Climate Change in Puget Sound” and the Surging Seas, Risk Finder Website.
 
The “State of Knowledge” series summarizes research on the probable effects of climate change on the water, lands and people of the Puget Sound. The synthesized work was created by the Climate Impacts Group, which aims to increase understanding and awareness of climate change through sharing information and conducting scientific studies. Data, projections and relevant research were all used to compile this report.
 
The Surging Seas tool aims to provide accessible, science-based, localized information to help people better understand and respond to the climate crisis as it specifically relates to rising sea levels. The National Oceanic and Atmospheric Association (NOAA) provides Surging Seas with accurate coastal elevation and tide station data. More scientific data was pulled from 2012 U.S. National Research Council records while population-specific data was obtained through the 2010 U.S. Census.

​Flooding and rising sea levels disproportionately harm vulnerable populations like the elderly, children, and people experiencing homelessness. The Thurston county homeless census found that 800 individuals were homeless or lived in emergency or transitional housing in 2019. While this is a slight decrease since the year prior, it is still a significantly large number. Many of these homeless individuals are unsheltered and positioned to be hit the hardest in the case of flooding or any other major climate events.
 
In addition to vulnerable communities being at risk from elevating sea levels, the effects of climate change will impact other areas as well. Agriculture lies along many rivers, infrastructure is vulnerable, homeowners and their property are at risk, and clean water sources may be contaminated. Climate change has the capacity to influence change in many areas and, eventually, everyone will be considered vulnerable regardless of their socioeconomic status.
 
When surveyed in 2016, residents of Thurston county had a higher than average awareness of climate issues, yet a lower than average concern for the personal toll that global warming will have on them.

Article author: Kiersten Kimminau, William O. Douglas Honors College, Central Washington University
Article editor: Dr. Tamara Caulkins, William O. Douglas Honors College, Central Washington University
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While salt marshes can be quite resilient to sea level rise, Jamaica Bay experiences a variety of other stressors that make it particularly vulnerable to this threat. Factors that exacerbate the already damaging effects of sea level rise include the general sediment deficit, a deepening of the Bay through dredging, waves generated by boat traffic, and excessive waterfowl grazing. While in less metropolitan areas, salt marsh loss can be compensated for by expanding the marsh onto adjacent upland or freshwater zones, Jamaica Bay shows the catastrophic repercussions of deteriorating salt marshes that have no hopes for expansion.

​Salt marshes in New York are one of the primary defenses against rising sea levels for coastal areas, but have been steadily deteriorating throughout the last several centuries. In New York State, salt marshes have reduced by 60% from 1780 to 1980. Field studies conducted in Jamaica Bay show that from 1989 to 2003, the Bay’s marshes were in rapid decline losing 13.4 ha/year. From 2003 to 2013, this has declined to 2.1 ha due to restoration efforts.

While the expected rising sea levels and future storms provide significant cause for concern, particularly in the Jamaica Bay region, this estuary is also a fascinating example of resilience in the face of climate change. In 2012, Hurricane Sandy tore through the northeast, causing significant flooding and massive devastation to infrastructure and coastal lagoons in the New York City area.

During Hurricane Sandy, Jamaica Bay experienced a storm surge of 8 to 10 feet during the worst of the storm. The damage felt after the storm was significant as well, with debris from destroyed homes and buildings coming from Queens and Brooklyn ultimately ending up in the Bay. Additionally, thousands of gallons of oil coming from home fuel tanks leaked into the area, creating yet another expense in the clean up after the storm.

The massive damages that Jamaica Bay, and the New York region as a whole, experienced from Hurricane Sandy displayed how instrumental proper governance and human action are in dealing with natural emergencies. Disaster relief funds provided swift critical aid to the region; however, many of these efforts were contained to the short-term and were more of a response tactic, rather than a preventative measure.

Despite the destruction New York City faced in 2012, human efforts have caused impressive improvement in the conditions of Jamaica Bay within the last two decades. Compared to 2003 when restorations first began, there has been a marked decrease in deterioration for the Bay. This ultimately was responsible for how swiftly the area recovered after Hurricane Sandy; however, constant monitoring is necessary, as even post-restoration, salt marsh loss continues to occur in the Bay. 

​Considering how important Jamaica Bay has historically been for the economic, social, and ecological health of New York, it is imperative that a concerted effort be made to help inoculate this area from the threats of future climate change, as rising sea levels and stronger storms will likely increase the risks facing the region.

Five Years After Hurricane Sandy, NYC’s Coastal Communities Remain Vulnerable. Curbed New York
Jamaica Bay Walloped by Hurricane Sandy. Queens Chronicle
New York Today: A ‘Maritime Forest’ Where Sandy’s Waters Rose. ​New York Times

As atmospheric temperatures around the world soar, oceanic water temperatures are increasing too, and glaciers and ice sheets are melting. Because water molecules in warmer water exhibit greater molecular movement, water expands in volume as it heats up. Furthermore, melting polar ice adds to the amount of water not in ice sheets, again causing a rise in sea levels globally.
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Nonetheless, it is important to recognize that regional variations in atmospheric and oceanic circulation patterns, in addition to other factors, also influence the extent of sea level rise. As global sea levels continue to rise, exposed coastal communities must be prepared for an increased risk of flooding. Barnstable County, located on Cape Cod in Massachusetts, has already experienced a sea level increase of 11 inches since 1922, almost 2.85mm annually. Its vulnerable coastal position, located on 550 miles (890 km) of shoreline, contributes to the risk of flooding in the County in the face of sea level rise. ​

Barnstable County has also seen an upward trend in annual precipitation levels. As the atmosphere warms, the rate of evaporation increases. Quicker rates of evaporation pulls more water into the atmosphere which is then accessible for precipitation. Thus, the overall trend of atmospheric warming contributes to the rise in both frequency and intensity of precipitation events. Despite the annual variation in precipitation levels, the general progression seen over the past century in the graph above shows increasingly wetter conditions for Barnstable County.

Hurricanes are also becoming more powerful as a consequence of warming global temperatures. Because hurricanes form over warm ocean waters, the increase in oceanic temperatures fuel hurricanes with more energy to activate higher peak winds and greater rainfall. Sea level rise also worsens the damages of hurricanes, as higher coastal inundation levels can increase the risk of storm-surge flooding. Although climate change does not necessarily impact the frequencies of hurricanes, it increases the severity of storms that have the potential to reach the coast of Cape Cod and cause tremendous damage. ​

The increased levels of precipitation, rising sea levels, and more powerful hurricanes have elevated the number of coastal flooding days in Barnstable County. These factors have not only made floods become more frequent, but have also made them more severe. The graph above shows the growing number of coastal flood days that can be linked to climate-driven sea level rise. ​The County has already experienced severe coastal flooding, and likely will suffer in the future as temperatures and sea levels continue to rise.

This information relies on data from easily accessible online tools including the National Oceanic and Atmospheric Administration (NOAA) Tides and Currents tool, the NOAA Climate at a Glance resource, and Climate Central’s Surging Seas: Risk Finder projections. It also draws on conclusions from a NOAA study connecting hurricane severity to global warming. 

The NOAA Tides and Currents resource collects data from over 100 water level stations in order to reconstruct sea level trends at the local level. The NOAA Climate at a Glance tool generates graphs using data gathered from weather stations to show trends in temperature, precipitation, and drought on global, regional, and local scales. Climate Central’s Surging Seas projections display sea level rise and flood risks for coastal locations.

Barnstable County Multi-Hazard Mitigation Plan. Cape Cod Commission
Massachusetts Hurricanes of the 20th Century. Massachusetts Office of Coastal Zone Management
Cape Cod Climate Change. The Boston Globe

Rising sea levels, an increase in overall precipitation, and more severe storms have greatly increased Fairfield County’s risk for floods. Over 130,000 people in the state are currently at risk of inland flooding, while heavy downpours and rising sea levels have strained the County’s sewer system. This stress on the County’s unprepared infrastructure has severely impacted both human and aquatic health. 

In particular, the rise in rain storms has increased levels of runoff. Within Fairfield County, the city of Bridgeport operates under a combined sewer system, meaning that rainwater runoff, domestic sewage, and industrial wastewater are all transported within the same pipe. During heavy storms where the rainfall exceeds the system’s capacity, the system is designed to overflow and release excess water into nearby bodies of water.

These overflows, called combined sewer overflows (CSOs), have considerable impacts on the local environment of Fairfield County. CSOs present an environmental and public health risk for the County, as the untreated wastewater that is discharged can contain bacteria, raw sewage, excess nutrients from fertilizers, and chemicals. This particularly impacted Bridgeport, as portions of the city’s sewer system were built over 100 years ago.

​The Connecticut Department of Energy and Environmental Protection found that a CSO occurs whenever there is 0.4 inches of precipitation or more. Overflows from the system occur on average every 10 days, releasing between 100,000 and 500,000 gallons of contaminated water into local rivers, streams, and harbors. With the increasing rate at which heavy downpours are taking place in Bridgeport, this leaves the public exposed to bacteria and raw sewage, creating a considerable health risk. 

The increasingly high levels of contamination have also undermined recreational activity, often leading to the closure of multiple beaches and parks. In Bridgeport the following parks, beaches, and harbors are constantly affected: Ash Creek, Bridgeport Harbor, Black Rock Harbor, Pequonnock Harbor, Johnson’s Creek, Yellow Mill Pond, Cedar Creek, Burr Creek, and Island Brook.  

Moreover, the loss of fishing grounds in Bridgeport has greatly disturbed the fishing industry. Leaked sewage has and will continue to kill tens of thousands of acres of shellfish beds. Additionally, hypoxia, or the overgrowth of algae that leads to dangerously low levels of oxygen for aquatic life, will continue to appear throughout the County as excess fertilizers enter these ecosystems. These “dead zones” are detrimental for aquatic species and will only further degrade the County’s water quality.

​Fairfield County, and specifically the Bridgeport Water Pollution Control Authority (WPCA), have already taken measures to combat the damages from CSOs. The WPCA has developed a plan to minimize the number of CSOs, and has implemented green infrastructure to prevent or delay stormwater from entering the sewer system. Although these efforts have helped reduce the number of overflows, Fairfield County nevertheless must invest in more infrastructure and a new system in order to mitigate the damages caused by stormwater runoff and severe floods.

Some CT beaches considered among the dirtiest. EyeWitness News
Water quality at Bridgeport, Fairfield beaches dropped in 2016. CT Post
Bridgeport plans massive sewer upgrades. CT Post
Combined Sewer Overflow Guide for City Employees. Bridgeport WPCA

These projections and reconstructions are based on freely accessible online tools from The National Oceanic and Atmospheric Administration (NOAA) Tides and Currents tool and the Climate Central Surging Seas: Risk Finder projections and tools. 

The NOAA Tides and Currents resource reports local mean sea level changes from 1850 to today. It uses data collected from U.S. and global water level stations to reconstruct local sea level trends.
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The Climate Central Surging Seas tool generates sea level projections based on the different emissions scenarios presented in the NOAA Technical Reports. This tool uses data from the San Francisco water level station to generate the coastal flood days graph.

A 2013 report from the Intergovernmental Panel on Climate Change layed out the specific ways in which global warming has changed, and will continue to shape, the planet’s many environmental systems. For Multnomah County, this means increasing average temperatures throughout the year, greater incidence of extreme heat days, and increased risk of flooding.

Multnomah County, home to the city of Portland, rests on the bank of the Willamette River. Even with conservative estimates of climate change and a global increase of only 1 degree Celsius, Portland would experience significant flooding of up to seven feet. With a global temperature increase of 2 degrees Celsius, the Limit set by The Paris Agreement on Climate, Portland would see fifteen feet of flooding.
 
Multnomah’s average temperatures are also predicted to increase, and have been increasing notably since the mid 1950s according to the chart from the National Oceanic and Atmospheric Alliance, and is predicted to rise at increasing rates for the next century. Even in the “low emissions” scenario, average temperature in Multnomah County is predicted to increase by about 4 degrees Farenheit in the next century, or up to 9 degrees Farenheit in the high emissions scenario.
 
While Oregon as a whole has a highly variable climate, Multnomah county is a fairly consistent climate zone, ranging from a 40° F average in January to a 68° average in July. However, extreme heat days are predicted to quadruple in frequency from about ten a year in 2000 to 40 a year by 2050. This will have major sociological and economic implications for the county.

​These projections primarily rely on two tools that are freely accessible online: the National Oceanic and Atmospheric Administration (NOAA) Climate Explorer app, and the Climate Central Surging Seas, Mapping Choices app.

The Climate Explorer tool uses weather information recorded by meteorological instruments at weather stations to reconstruct past climate changes. It uses supercomputer simulations of future climate changes under both high and low emissions scenarios. 

The Surging Seas tool combines historic flood statistics and local sea level trends with global scenarios of sea level increases, which were compiled in the 2014 U.S. National Climate Assessment. ​

​Data from simulations like these is then combined with studies of local economy, current local policy, and state infrastructure to create resources like America’s Preparedness Report Card from Climate Central and ICF International. This resource synthesizes climate and sociological data and grades each state on its level of preparedness for each of five future climatological hazards related to climate change.

In America’s Preparedness Report Card, Oregon as a whole received an “F” in Extreme Heat preparedness. Though extreme heat is not currently a major risk to the state, the projected increase of extreme heat days and Oregon’s lack of policy or public health plans designed to deal with that increase leaves Oregon, and Multnomah County, in a risky position. Extreme heat disproportionately harms vulnerable populations like the elderly, young children, and people experiencing homelessness. Without proper planning, Multnomah is unprepared for the public health costs and risks to its citizens that an increase in extreme heat days will bring.

The increased frequency of wildfires and decreased air quality overall in the city of Portland already affects Multnomah county residents, and is predicted to worsen in coming decades, leaving asthma sufferers and others with compromised respiratory systems at particular risk for life threatening health complications.
 
On a more general level, the Willamette Valley, including Multnomah County, is the most diverse agricultural area of the state, and is, therefore, reliant on predictable and consistent climatological and weather patterns to maintain this industry sector. Agriculture and recreation are major sectors of the Oregon economy, and even more so for Multnomah County at the intersection of agriculture and tourism from Portland. Therefore, damage from climate change—droughts and subsequent crop failures, urban space loss, and resident migrations—would be a major financial burden to the area.
 
When surveyed, residents of Multnomah county have a higher than average awareness of climate issues, as well as higher than average concern over the impact of climatological effects. However, despite local governmental and community adaptations made to address the changing climate, a few key oversights leave Multnomah County vulnerable to the public health and infrastructural risks of climate change.

Oregon. States at Risk.
Symptoms of Climate Change. Oregon Public Broadcasting

​Monmouth County spans across the lower portion of the neck of New Jersey, extending to the eastern coastline. A 2011 report from Columbia University identifies sea level, storm surge, and precipitation, all of which are expected to increase within the next century, as primary climate change associated concerns for New Jersey’s coastal areas.

​High concentrations of long-lived greenhouse gases like carbon dioxide and methane in the atmosphere are causing warmer global temperatures. The result is thermal expansion and melting glacier mass that contribute to an increase in sea levels. Sea levels along the Jersey Shore have already risen 0.36 meters in the last century, and that number will increase sixfold to 2 meters by 2100. Moreover, a 2ºC increase in global temperatures will further this sea level increase to 4.7 meters. The renown beaches of the area will cease to exist as a result of sea level rise, negatively affecting marine life. Resulting higher flood levels will also disrupt wetlands and terrestrial life further in the county as they become open water. Plant composition and communities will, in fact, change, a disruption that will resonate with other organisms.

Warming global temperatures will also increase the amount of precipitation the county will experience. Early snowmelt will make for wetter winter and spring months though this will actually intensify summer dryness.

The warmer ocean surface temperatures are also likely to increase both the frequency and intensity of hurricanes that hit the area. Hurricanes increase both in frequency and in strength with warming sea surface temperature (SST). Projections predict more hurricanes like 2011’s Irene and 2012’s Sandy, both of which disrupted activity in Monmouth County, mostly due to flooding. 

These projections primarily rely on two tools that are freely accessible online: the National Oceanic and Atmospheric Administration (NOAA) Climate Explorer app, and the Climate Central Surging Seas, Mapping Choices app.

The Climate Explorer tool uses weather information recorded by meteorological instruments at weather stations to reconstruct past climate changes. It uses supercomputer simulations of future climate changes under both high and low emissions scenarios. 

The Surging Seas tool combines historic flood statistics and local sea level trends with global scenarios of sea level increases, which were compiled in the 2014 U.S. National Climate Assessment. ​

The continuing increase in global temperatures will impact important industries, local businesses, and homes significantly as  sea levels rise due to warming oceans and melting glacier mass. Beach erosion will contribute to much of the blow the region receives since they serve as a great source of revenue for the area by attracting tourists and allowing the growth of local businesses. The county’s coastal lakes are also integral in its commercial and recreational activities, and significant changes in the waters present an alarming concern for Monmouth county inhabitants. Notably, the shellfish industry that makes up 66% of  New Jersey’s commercial fishing revenue is at risk as the population of such organism decrease as a result of ocean acidification.

Similarly, homes along the coast will be destroyed due to greater storm surges.  Over 9,000 homes ($5 billion in property value) housing 18,000 people will be at a 97% risk if Monmouth County sea levels reach the projected 4.7 meters. Thus, the livelihood of the county’s coastal inhabitants is in danger due to anthropogenic global warming leading to rising sea levels and flooding. The impacts of these climate change related changes will be especially hard-felt among low-income communities who have a high vulnerability.

Moreover, hazardous waste sites that in areas predicted to experience high level of flooding present an additional worry for Monmouth County as flood waters can release harmful materials. While 2100 and the projected sea level and flooding changes seem far away, the threat they pose calls for immediate action. New Jersey has taken several mitigation measures to increase the resilience of its inhabitants. However, these efforts only confer higher taxes on the population in order to push forward rebuilding initiatives. 

What Climate Change Means for New Jersey. EPA

Haiti is a country prone to extreme weather: floods, droughts, and especially hurricanes. Typically, hurricanes make landfall on the southern coast of Haiti, and as a result communities located there experience the greatest storm surges. The largest city on a south-facing coastline is the commune of Gonaïves.

The frequency of Atlantic hurricanes has increased sharply since the 1980s, and seems to have risen overall since the 19th century. However, it is hard to determine exactly how many hurricanes churned through the Atlantic before the widespread use of weather satellites. Our understanding of long-term trends in hurricane frequency may therefore be skewed by early underreporting of remote or short-lived hurricanes. 

Still, it seems clear that major hurricanes in particular have grown more common as sea surface temperatures warm across the Atlantic, and particularly in the Caribbean Sea. Hurricanes are fueled by warm, moist air rising from warm water. The warmer the water, the more fuel hurricanes can use.

The most powerful hurricanes, with sustained winds at or above 130 mph (209 km/h), have rarely made landfall in Haiti. Category 5 hurricane Irma, for example, only lightly grazed northern Haiti. Yet substantial hurricanes have recently made made landfall in Haiti and caused catastrophic flooding in Gonaïves. Moreover, hurricane storm surges are higher now than they once were, owing in part to a modest but sustained increase sea levels on the Haitian coast. 

Hurricane floods have also been slow to recede from Gonaïves, owing to surrounding mountains that trap water within the commune. Long-lasting floods have raised the salinity of soil and groundwater around Gonaïves, and have thereby repeatedly hindered rice cultivation. Meanwhile, deforestation on and around the mountains near Gonaïves has led to mudslides amid torrential rainfall during and after hurricanes.  

This summary makes use of reconstructions compiled by the National Oceanic and Atmospheric Administration (NOAA) National Hurricane Center, which provides easy to use visualizations that record the history of hurricanes in the Atlantic Basin. 

​It also draws on an overview of changes in hurricane frequency provided within the U.S. National Climate Assessment, and a skeptical assessment of hurricane trends published by the NOAA Geophysical Fluid Dynamics Laboratory. 

Haiti today is almost entirely deforested, and that has greatly increased the vulnerability of its coastal cities to hurricanes. Beginning in the seventeenth century, European settlers imported slaves from Africa to work in plantations that destroyed much of the indigenous forest of the island of Hispaniola, which includes Haiti. Late in the twentieth century, impoverished Haitians destroyed almost all the forests that remained in order to exploit charcoal. With oil and coal too expensive for most Haitians to afford, charcoal provided one of the few accessible sources of fuel. Exposed hillsides now offer no resistance to floodwaters, and easily crumble in devastating mudslides. Meanwhile, nearly all of Haiti's watersheds are deforested. 

In this context, active hurricane seasons can provoke human suffering on a vast scale across Haiti, and those seasons have grown more common. In 2004, for example, Hurricane Jeane dropped 13 inches of rain on the northern mountains of Haiti and caused catastrophic flooding in and around Gonaïves. Nearly 3,000 Haitians lost their lives. In 2008, no fewer than four hurricanes made landfall in Haiti. Floods were particularly devastating in Gonaïves, but overall houses belonging to nearly 800,000 Haitians were either damaged or destroyed. Floods swept away roughly 70% of Haiti's crops and thereby provoked widespread hunger and malnutrition. Festering flood waters provided ideal conditions for the spread of cholera, malaria, and West Nile disease. In 2016, Hurricane Matthew, a major category 4 storm, devastated southern Haiti and killed over 900 people. 

Haitians have not remained passive in the face of these challenges. Recently, the Haitian government has partnered with international aid groups and celebrities to launch a major reforestation program. International efforts, meanwhile, aim at reducing social and gender inequality across Haiti, and thereby fostering resilience to climate change in communities such as Gonaïves. 

​Mean global sea levels have risen by at least 17 cm (nearly 7 inches) in the twentieth century. Yet regional variations in ocean temperatures, prevailing winds, ocean currents, and the rise or fall of Earth's crust mean some areas have experienced, and will experience, greater sea level increases than others.

Over the past century, sea levels of Charleston, South Carolina have risen by nearly one foot (30 cm, or 12 inches), and have increased by an average of 3.2 mm per year. In recent decades, rising sea levels have sharply increased the risk of flooding in Charleston during periods of heavy rain. Average annual precipitation has increased only modestly in Charleston, but rainstorms have grown significantly more common.
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As sea levels climbed, floodplains have also increased in size, meaning that more people and property each year became vulnerable to flooding. Nuisance flooding, or flooding from high tides without a storm, is four times more common in Charleston today than it was in 1950.

​Meanwhile, hurricanes and tropical storms have grown more powerful and more capable of causing catastrophic flooding when they make landfall. From 1975-1989, roughly 20% of hurricane strengthened to category 4 or 5, with winds at or above 130 mph (209 km/h). From 1990-2004, the share that reached at least category 4 had increased to 25%. Hurricanes are fueled by warm, moist air rising from warm water. The warmer the water, the more fuel hurricanes can use.

In recent years, sea surface temperatures have provided ample fuel for hurricanes that ultimately made landfall in South Carolina. Hurricane Matthew made landfall in 2016, and hurricane Irma reached Charleston as a tropical storm in 2017. Though much weakened from the historic intensity it reached in Caribbean, Irma brought a high tide of nearly 10 feet to Charleston, which sent flood waters cascading into the city. 

Tropical storms and hurricanes have crippled coastal cities like Charleston. In 1989, for example, hurricane Hugo swept ashore in South Carolina as a category 4 storm. It was fast-moving, and it therefore dropped only a relatively modest amount of rain. Yet its power resulted in a storm surge that reached 20 feet in some stretches of the South Carolina coast. Sustained winds in downtown Charleston reached 87 mph (140 km/h), but gusts exceeded 108 mph (174 km/h). The wind and water destroyed rows of beach houses, shattered docked boats, and collapsed part of the Ben Sawyer Bridge. The storm caused nearly $12 billion (2017 USD) in damage and directly or indirectly resulted in 35 deaths across South Carolina. 

In 2017, Irma sent roughly 4 feet of ocean water spilling into downtown Charleston and caused the worst flooding in the city since Hugo made landfall. Since residents had not been ordered to evacuate, many were caught off guard by the flooding, and some needed rescuing. Irma was the costliest storm to reach Charleston since Hugo, and caused well over $1 billion in damage across South Carolina. 

​The Front Lines of Climate Change: Charleston’s Struggle. Climate Central
Your Post-Storm Update: Charleston Assesses Irma's Damage. The Post and Courier

As global sea levels rise, regional variations in ocean temperatures, prevailing winds, ocean currents, and the rise or fall of Earth's crust mean that some communities have experienced, and will experience, greater sea level increases than others. Sea levels off Suffolk County, Long Island, for example, are rising at a rate of around 3.23 mm/year, which is up from 2.78 mm/year just one decade ago.

New York State is in fact sinking relative to the sea, owing to a combination of human activity and the slow rebound of the landscape following the retreat of the great glaciers that covered the state during the last ice age. Meanwhile, the melting of polar ice sheets and the warming of Earth's oceans mean that seal levels off the state are projected to increase steadily. If emissions of greenhouse gases continue unabated, and average global temperatures rise by around 4° C (roughly 7° F) relative to twentieth-century averages, then the entire southern coast of Long Island, including that of Suffolk County, will eventually be inundated. Montauk, the tip of Suffolk County, will then become its own island, separated from Long Island by a chasm of water. 

Winters, meanwhile, are expected to grow shorter but wetter, and major storms - such as Superstorm Sandy - are projected to grow more common. Storm surges will likely threaten natural defenses against the sea, including saltwater marshes and dunes, in ways that may permit even more extensive flooding. 

These projections and reconstructions are largely based on reliable, easy to use tools that are freely accessible online: the National Oceanic and Atmospheric Administration (NOAA) Sea Level Trends app, the NOAA Climate Explorer app, and the Climate Central Surging Seas, Mapping Choices app. 

The Sea Level Trends tool shows regional mean sea level changes from the twentieth century through today. NOAA collects data for these measurements through the 142 long-term tide stations of the National Water Level Observation Network, which has been measuring sea level for over 150 years. Each regional mean sea level rise or fall is computed using a minimum of 30 years of data to ensure accuracy. 

The Climate Explorer tool uses weather information recorded by meteorological instruments at weather stations to reconstruct past climate changes. It uses supercomputer simulations of future climate changes under both high and low emissions scenarios. The Surging Seas tool combines historic flood statistics and local sea level trends with global scenarios of sea level increases, which were compiled in the 2014 U.S. National Climate Assessment.
 
These projections also make use of a map designed by the New York State Department of Environmental Conservation, which shows the extent of low-lying coastal areas around Suffolk County. 

New York State is the third largest coastal flooding threat in the United States, and in 2008 it was reported that about 13.9 percent of the state's residents live directly on the coast. Many towns in Suffolk, particularly some of those located on the southern border, are precariously close to the sea. Even in scenarios that assume drastic action to curb human-caused greenhouse gas emissions, many of these towns will be underwater. Well before that happens, rising sea levels and intensifying storms will batter coastal infrastructure. 

Today, warming sea surface temperatures are already undermining the quality of local drinking water, and the health of coastal ecosystems, by creating ideal conditions for toxic bacteria. Wetlands that help filter pollution from water flowing out to sea, meanwhile, are vulnerable to rising sea levels and intensifying storms. Further inland, rising temperatures will encourage the spread of pollen, ragweed, and poison ivy, will creating more favorable conditions for Lyme disease. Suffolk County, in short, is set to become a far less healthy place for its inhabitants and the ecosystems on which they depend. 

In response, municipal, state, and federal governments have mobilized to shore up flood defenses - such as coastal dunes - while some county residents have elevated their coastal homes and businesses. In the long run, however, coastal areas of the county will either need to be protected using very expensive defenses against the sea, or evacuated to make way for the rising waters. 

Climate Change Could Threaten Long Island. The Weather Channel
Coastline Population Trends in the United States: 1960 to 2008. US Census Bureau