What will flood in Virginia if sea level rises 5-10 feet, or more...
Source: Environmental Protection Agency, Maps of Lands Vulnerable to Sea Level Rise: Modeled Elevations Along the U.S. Atlantic and Gulf Coasts
Sea level 135,000 years ago were approximately at today's level. Water was then trapped in continental ice sheets until the Last Glacial Maximum was reached about 20,000 years ago. At the time, sea level was 400 feet lower than today.
For the next 6,000 years, gradual global warming led to a 60-70 foot rise in sea level. A pulse of melt water created a rapid rise for 1,000 years that could have been as fast as 53 mm/year. During the Younger Dryas period of global cooling around 12,900-11,800 years ago BP (Before Present), the rate of sea level rise slowed substantially. A second melt water pulse 8,200 years ago created another period of rapid sea level rise. Gradual melting of ice sheets followed, and sea levels stabilized about 6,000-7,000 years ago.1
after the Last Glacial Maximum, sea level rise included irregular melt water pulses
Source: National Aeronautics and Space Administration, The Great Ice Meltdown and Rising Seas: Lessons for Tomorrow
If the earth warms at rates predicted by some studies, the oceans will rise for two main reasons - the expansion of the existing water as it heats, and the addition of additional water as the ice melts off the land at Antarctica. Sea level rise will affect primarily the eastern edge of Virginia, while changes in rainfall/temperature will affect the entire state.
Scientists are monitoring two species that grow on rock outcrops in Shenandoah National Park, three-toothed cinquefoil and Appalachian fir clubmoss. Virginia's mountains are the edge of the current range for those species, so increased temperatures could cause the two species to disappear from Virginia.2
Predictions about global warming by 2080 if emissions of greenhouse gases are not constrained suggest that Virginia cities will experience temperatures now common in Texas and Alabama. Species adapted to Virginia's current climate may disappear, especially if they are at the southern end of their habitat range. Warming temperatures could cause red spruce, brook trout, yellow birch, northern red oak, eastern hemlock, white pine, and the wood frog to disappear from the state.
Populations of species now near the northern limit of their range, including the oak toad, Cope's gray treefrog, and the bald cypress, may increase within Virginia as temperatures and rainfall increase. Adaptation to changing habitats is a normal process. Species ranging from mastodons to mallard ducks occupied new territory as the ice sheet withdrew from Pennsylvania 18,000 years ago.3
Virginia cities in 2080 will experience temperatures and rainfall currently common much further south
Source: University of Maryland, What will climate feel like in 60 years?
Sea level is rising at nearly an inch a century now on the Atlantic Ocean coastline of Virginia. If the rise continues at that rate, Jamestown Island will be underwater in 2107 during the 500th anniversary of the arrival of English colonists.
In a thousand years the Eastern Shore, Virginia Beach, Norfolk, Chesapeake, and Suffolk could be underwater or become offshore sandbars. Since Europeans began mapping the Chesapeake Bay, over 500 islands have disappeared. By the end of the 1800's, news stories noted how the islands weee washing away. Holland Island in Maryland had over 350 residents in 1910, living on 160 acres. The last house remaining, which had been built in 1888, collapsed in 2010 as the remnants of the island washed away.
Sea level rise has not been steady for centuries. It increased significantly around 1850, as the Industrial Revolution increased emissions of greenhouse gases and spurred warmer sea temperatures. On Average, the edge of marsh and forest is moving 1.6 feet inland each year in the Chesapeake Bay. Saltwater is poisoning the roots of the trees, killing them and creating "ghost forests."
Today sea level is rising faster than wetlands can migrate inland. One result is that the wetlands are sequestering carbon at a higher rate. Organic material is being buried, and carbon concentrations in the sediments are substantially higher than in the past.4
the last house on Maryland's Holland Island, built in 1888, washed away in 2010
Source: Flickr, Water front home for sail (by baldeaglebluff, October 21, 2009)
In the next century, the costs of insurance will reflect the perceived risks of flooding during a major storm. Insurance costs will rise, driving new development inland, long before buildings in Norfolk are recycled as oyster reefs or fish swim through the windows.
the Union of Concerned Scientists predicts nearly half of homes at Chincoteague will be flooded regularly by 2045
Source: Union of Concerned Scientists, US Coastal Property at Risk from Rising Seas
Seawalls and bulkheads can armor the shoreline temporarily. At some point, only retreat from the rising water will be cost-effective. Civic leaders who champion new development in Norfolk and Virginia Beach, such as the Tide light rail system, will be forced to consider the option of moving infrastructure further inland.
Even a Category 1 hurricane can create a disaster now. On September 6, 2019, Hurricane Dorian sent a seven-foot high storm surge from Pamlico Sound over Ocracoke Island in North Carolina. Nearly every building experienced flood damage, and after another winter storm damaged NC 12 the island could not reopen for tourists until December 2.
As residents assessed how many more storms their tourism-based economy could survive before government agencies stopped financing recovery and rebuilding efforts, a county commissioner commented:5
in Prince William County, houses on Bay Street east of Veterans Park are at risk if sea level rises four feet
Source: Citizens Climate Lobby, Surging Seas Risk Zone Map
In Virginia, 48% of energy-related CO emissions in 2017 were generated by the transportation sector, primarily from cars, trucks, trains, and airplanes.6
in 2017, the largest sector of the economy generating carbon dioxide was transportation
Source: US Energy Information Administration, 2017 State energy-related carbon dioxide emissions by sector
the Environmental Protection Agency calculated the transportation sector generated less than one-third of total geenhouse gas emissions in 2019
Source: Environmental Protection Agency (EPA), Inventory of U.S. Greenhouse Gas Emissions and Sinks and Greenhouse Gas Inventory Data Explorer
Natural gas is primarily methane, and methane molecules trap more heat than carbon dioxide molecules. Today, 60% of methane in the atmosphere is generated by human activities. Roughly 30% come from wetlands, and the remaining 10% from natural processes such as fires, thawing permafrost, and even emissions from termites as they decompose wood.
Though methane molecules break down after a decade in the atmosphere, they are responsible for roughly 20% of the global warming that has occurred since the start of the Industrial Revolution in the mid-1700's. Since 1750, the methane concentration in the atmosphere has increased 150%.
Construction of new pipelines to increase use of natural gas has been controversial in Virginia. The Atlantic Coast Pipeline was cancelled after years of opposition, reducing the potential for importing "fracked" gas from Ohio, West Virginia, and Pennsylvania.
Oil and gas development has increased methane emissions from intentional releases at wells and leaks in the pipeline transmission network. About 25% of the human-caused methane releases are associated with energy, while 14% comes from wastewater treatment and landfills. Some human-caused methane is due to agriculture; livestock emit methane as they digest vegetation.7
the average temperature has been rising in Virginia since 1970
Source: National Oceanic and Atmospheric Administration, Temperature Trends by State
in the Pliocene Epoch three million years ago, sea levels were higher and the coastline was at modern I-95
Source: Dr. Ron Blakey, Paleogeography and Geologic History of North America
climate change will result in higher average temperatures in summer months (1981-2010 on top, 2040-2059 on bottom)
Source: Climate Impact Lab, Climate Impact Map