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Sea Levels Rising - Global Warming Forecasts


The challenge is we have built most of our civilization within a few feet of sea level or right at the edge.

— Gary Griggs, January 2011
Director, Institute of Marine Sciences,
University of California, Santa Cruz
Co-Author, Living With
the Changing California Coast


2015 | Rising Seal Levels

2015. Lagos, Nigeria projected to be at risk from sea level rise.  "Nigeria will suffer from climate-induced drought, desertification, and sea level rise. Already, approximately 1,350 square miles of Nigerian land turns to desert each year, forcing both farmers and herdsmen to abandon their homes.  Lagos, the capital, is one of the West African coastal megacities [along with Alexandria, Egypt] that the IPCC identifies as at risk from sea level rise by 2015. This, coupled with high population growth (Nigeria is the most populous nation in Africa, and three-fourths of the population is under the age of 30), will force significant migration and contribute to political and economic turmoil.  It will, for instance, exacerbate the existing internal conflict over oil production in the Niger Delta." (Alexander T.J. Lennon, Jay Gulledge, J.R. McNeill, John Podesta, Peter Ogden, Leon Fuerth, R. James Woolsey, Julianne Smith, Richard Weitz, and Derek Mix. The Age of Consequences: The Foreign Policy and National Security Implications of Global Climate Change, Center for Strategic and International Studies, Washington, DC, November 5, 2007) See videos about Lagos, Nigeria sea level rise impacts

2025 | Sea Level Rise

2025.  Sea levels forecast to rise up to 10 inches by 2025 based on a 3 degree Fahrenheit rise in ocean temperatures.  “As global temperatures rise because of the greenhouse effect, oceans levels expand by the warmer water temperatures and because of the glacial melting, according to John S. Hoffman, director of EPA's Strategic Studies staff, which conducted [the Sea Level Rise Project].  The study provided two scenarios on the possible effects over the next 40 to 100 years.  The low scenario, based on on the calculated three-degree rise in ocean temperatures, will make the seas rise . . . up to 10 inches by 2025.  Such an increase by 2025 would be enough to 'significantly increase (storm and erosion) hazards at places like Ocean City [Maryland].' Hoffman said. . .

For barrier islands like Ocean City, according to Stephen P. Leatherman, a University of Maryland coastal geographer who participated in the research, the results would differ, depending on the scenario.  'Even the rate of sea level rise in the low scenario would mean erosion problems two or three times worse than what they (Ocean City) are seeing now, and the high scenario would be almost catastrophic — at least a major, major increase in storm hazards, there,' he said.  One big problem cited by Hoffman is that around the United States there are already 1,137 active hazardous-waste disposal sites located in 100-year floodplains, areas where major innundations should occur at least once a century.” Climate change 2025.  (Associated Press, "Greenhouse effect' may harm bay water," Frederick News-Post, Frederick, Maryland, May 2, 1983, p. 13)

2025.  Maryland shoreline in Somerset County projected to be eroded back 17 feet with a 2 inch sea level rise by 2025.  “In August [2008], consultants with URS Inc. presented a draft report [Somerset County, Maryland : Rising sea level guidance] on sea level rise to the Somerset County Planning and Zoning Commission. They predicted that by 2025 the shoreline will be eroded back some 17 feet across the board [with a sea level rise of 2 inches or 53 mm], increasing to 42 feet by 2050 and 92 feet by 2100. The greatest impact will be in the Deal Island and Chance communities, while Smith Island for the most part will be underwater just 90 years [2098 or ca. 2100] from now. . . .

The URS consultants are basing their report on historical data by predicting a 2 inch increase in average sea level by 2025, 5 inches by 2050 and one foot by 2100. [Somerset County Technical and Community Services Director Jack Willing Jr. ] said the state [of Maryland] is forecasting a two to three foot rise with four feet ‘the worst case scenario.’ He asked the consultants to modify their report accordingly.  Kyle Gulbronson, the senior planner and project manager with URS, said four feet ‘is a doomsday scenario’ for much of the county. The effects "will be dramatic," he said.” (Richard Crumbacker, Crisfield Times, “Storm gives look into the future - Consultants predicted vulnerable areas, and high tide showed it,” Crisfield Times, Crisfield, Maryland, September 10, 2008, pp. 1, 3 reporting findings in URS & RCQuinn Consulting, Inc., "Somerset County, Maryland : Rising sea level guidance," a report to the Maryland Coastal Zone Management Program, Department of Natural Resources pursuant to NOAA Award No. NA05NOS4191142, September 24, 2008, p. 14) 

2025.  Sea levels projected to rise 1.5 inches to 3.1 inches by the year 2025.  “Sea levels may rise by 1.5 inches to 3.1 inches by the year 2025 from expansion of ocean water in a warming climate, a prediction says.  But forecasting the total sea level rise will require estimating the contribution of runoff from melting glaciers, ‘a daunting task,’ researchers said.  The projected increase from thermal expansion, calculated for 1985 to 2025, compares to previous published estimates of 2.3 inches to 4.3 inches, they said.  The study [Thermal Expansion of Sea Water Associated with Global Warming] in the British journal Nature, was prepared by Tom Wigley and S.C.B. Raper of the University of East Anglia in Norwich, England. Mr. Wigley now is working at the National Center for Atmospheric Research in Boulder, Colo.  Changes in sea level are being studied as one consequence of the ‘greenhouse effect,’ a warming of the global climate due to a buildup of certain gases in the atmosphere. 

Over the last century, global average temperature has increased by about nine-tenths of a degree Fahrenheit and sea level has risen by about 4 to 6 inches, the researchers wrote. But the relative contributions of ocean water expansion and glacial melting are unknown and estimates vary widely, they said.” (“Rise Forecast In Sea Levels By Year 2025,” The Journal of Commerce, New York, New York, November 19, 1987, p. 10B citing findings in Wigley, T.M.L. and Raper, S.C.B., 1987, “Thermal Expansion of Sea Water Associated with Global Warming,” Nature, 330, 127-131, 18 November 1987) 

2025.  EPA predicts rise in sea levels of 2 feet by 2025.  “The doomsday headlines (Sunbelt Moving North, Warming Spells Disaster) were unduly alarmist, and much of the information was well known to scientists. But last week a media brouhaha was triggered by new studies from the Environmental Protection Agency and the National Academy of Sciences. Both groups agreed on a startling prognosis: the earth is warming up from all the carbon dioxide being spilled into the atmosphere by the burning of fossil fuels, and worse, the first effects of the climatic changes could be felt as early as the 1990s.  The EPA predicted temperature increases of nearly 4° F by the year 2040; a rise in sea levels of  2 feet by 2025 (thereby inundating some low-lying areas in coastal cities such as Charleston, S.C., and Galveston, Texas); and drastically changing rainfall patterns, especially in the breadbasket areas of the Midwest, where reduced precipitation could jeopardize crops. Nothing, not even a sharp cutback in the use of fossil fuels, the EPA added, could alter this climatic course.” Emphasis added. Global warming 2025.  (Frederic Golden and Jay Branegan, “Environment: Hot Times for the Old Orb,” Time Magazine, Monday, Oct. 31, 1983)

Sea Level Rise Impacts of Arctic and Antarctic Melting


We have already reached a tipping point where we will soon see an ice-free Arctic Ocean in the summer. 

There's nothing we can do about that. It could be in 2015.  It could be in 2025.  It almost doesn't matter.  It'll happen in this generation. 

As a result, the whole weather system could change. (1)

— Dr. David Carlson
Director, International Polar Year
July 2009


 2030 | Rising Sea Levels

2030.  1 foot.  California sea levels expected to rise up to one foot by 2030.  “Sea levels along the California coast are expected to rise up to 1 foot [2 inches to 12 inches] in 20 years [2030], 2 feet by 2050 and as much as 5 1/2 feet by the end of the century [2100], climbing slightly more than the global average and increasing the risk of flooding and storm damage, a new study says.  That's because much of California is sinking, extending the reach of a sea that is warming and expanding because of climate change, according to a report by a committee of scientists released Friday [June 22, 2012] by the National Research Council. . . . The report, commissioned by California, Oregon, Washington and several federal agencies, is the closest look yet at how global warming — which causes ocean water to expand and ice to melt — will raise sea levels along the West Coast. . . .

Although the rise in sea levels will happen gradually, [Gary Griggs, director of the Institute of Marine Sciences at UC Santa Cruz and a member of the committee that produced the report] said, its destructive power will be felt first when storms hit vulnerable places such as Newport Beach and the San Francisco Bay.  ‘In the short term it's these severe storms in low-lying areas that are most problematic,’ Griggs said.” ” (Tony Barboza, “California sea levels to rise 5-plus feet this century, study says,” Los Angeles Times, Sunday, June 24, 2012 reporting findings of Committee on Sea Level Rise, Dalrymple et al, Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future, National Research Council, National Academy of Sciences, National Academies Press, Washington, DC, Friday, June 22, 2012)

2020 - 2030 - 2040.  Time frame when Arctic ice mass may completely melt.  “The ice mass in the Arctic might melt completely sometime between 2020 and 2040, causing Greenland to turn, well, green. ‘If that happens,’ says Larry J. Schweiger, president and CEO of the National Wildlife Federation, ‘sea levels would eventually rise over 14 feet higher.’ That would flood millions of people across the planet.” (Rick Telander, “Time to warm up to reality,” Chicago Sun-Times, January 4, 2008)

Sea Level Increases in California, Oregon & Washington

The Pacific Coast of the Western United States has already experienced large waves and surges at high tides that have exceeded mean sea levels expected for the end of this century.  For the next several decades (2012 - 2020 - 2030 - 2040), these large wave events pose a greater hazard to the West Coast than the longer term climate-driven rise expected by the year 2100. The impacts of these large wave surges are likely to become more frequent and greater in magnitude.


2040 | Sea Level Rise

2040.  Two foot sea level rise projected for Ventura County, California coastline by 2040.  “Rising sea levels over the next 50 years could swamp hotels, power plants, the Point Mugu military base and as many as 4,100 low-lying houses along the Ventura County [California] coastline during big storms [Pierpoint Bay, Ventura Harbor, Edison Power Plant, Oxnard Shores, Hollywood Beach, Channel Islands Harbor, Silver Strand, Port of Hueneme, Hueneme Beach, Ormond Beach, Point Mugu], according to a new study of global warming by a USC research team. . . .

Researchers [led by Angela Constable, lead author of the climate change report], who studied Ventura County as a model for California's coastal communities, said they expect a sea-level rise of about 2 feet by 2040, and that local governments' reaction to the threats of sea rise and beach erosion will determine how much damage actually occurs.” (Daryl Kelley, Times Staff Writer, “Study Envisions Rising Sea Levels, Disaster - Global warming: USC team says 2-foot rise by 2040 could threaten roads and thousands of local coastal houses if steps aren't taken,” Los Angeles Times, Los Angeles, California, March 16, 1997 reporting findings in Angela Constable, Maurice D. Van Arsdol, Jr., Jiankiang Wang, Pamela A. McMullin-Messier, and Louise Rollin, “Demographic Responses to Sea Level Rise in California,” World Resource Review, Vol. 9, No. 1, 1997, pp. 32-44).  [See Constable et al map of projected Ventura County sea level rise.]

2050 | Rising Sea Levels

2050 .  1 to 4 feet. Ocean waters projected to rise one to four feet by 2050 threatening the homes of 25 million to 40 million people.  "Most experts foresee an increase of at least 0.6 of a degree Fahrenheit before the middle of the next century.  Seas would rise as higher temperatures made water expand much as they do sidewalks:  thermal expansion has already raised sea levels four inches since the turn of the century.  Polar ice caps might also partially melt.  All this would lift the waters one to four feet by 2050 and threaten the homes of 25 million to 40 million people worldwide."  (Newsweek, July 11, 1988, p. 19)

2050. Several feet.  Sea level projected to rise several feet by the year 2050. 
“Whether the greenhouse effect has arrived or not, some scientists calculate that global temperatures could increase between 3 degrees and 9 degrees F by the year 2050. If that happens, even hotter, dryer summers are on the way, probably accompanied by a gradual melting of polar ice caps and glaciers that will cause sea levels to rise several feet by mid-century. By then it is probable that more CO2 production, from sources as diverse as industry and rampant deforestation, will play an increasingly important role in heating up the earth.” (David Brand, Andrea Dorfman-New York and Dick Thompson-Washington, “Is The Earth Warming Up?,” Time Magazine, Monday, July 4, 1988)

2050.  Rising sea levels projected to inundate coastlines where millions live. 
"Although scientists argue over whether the greenhouse has already arrived, there is no dispute that industrial emissions will cause global warming.  The chief culprits are carbon dioxide (CO2), emitted when such fossil fuels as coal and oil burn, and chemicals called CFC's used in plastic foams and air conditioning.  These 'greenhouse gases' act like panes of glass, trapping heat near the surface of the earth.  The result:  global temperatures are expected to rise 2 to 9 degrees Fahrenheit by the middle of the next century.  There would be greater increases at higher latitudes, smaller rises near the equator.  Wind and rainfall patterns would shift, with possibly disastrous consequences for agriculture.  Sea levels would rise, inundating coastlines where millions of people live.  Droughts would get worse and storms more violent."  (Newsweek, May 22, 1989, p. 80)

2100 | Global Warming Sea Level

2100 (3 to 5 feet).  A minimum 3 to 5-foot sea level rise should be anticipated by 2100.  “[M]ost climate scientists now believe that the main drivers of sea level rise in the 21st century will be the melting of the West Antarctic Ice Sheet (a potential of a 16-foot rise if the entire sheet melts) and the Greenland Ice Sheet (a potential rise of 20 feet if the entire ice cap melts). [16 feet + 20 feet = 36 feet] The nature of the melting is non-linear and is difficult to predict.  Seeking to correct the IPCC’s failure to come up with a comprehensive forecast for sea level increase, a number of state panels and government committees have produced sea level rise predictions that include an examination of melting ice sheets. For example, sea level rise panels in Rhode Island and Miami-Dade County have concluded that a minimum of a three- to five-foot sea level rise should be anticipated by 2100.” (Rob Young and Orrin Pilkey, “How High Will Seas Rise? Get Ready for Seven Feet,” Yale Environment 360, January 14, 2010)

2100 (1.5 to 7 feet).  Global warming projected to cause 1.5 – 7 feet sea level rise by 2100.  “Published estimates of sea level rise due to global warming generally range from 0.5 to 2.0 meters (1.5 to 7 feet) by 2100.” (U.S. EPA, The Potential Effects of Global Climate Change on the United StatesEPA-230-05-89-050, Office of Policy, Planning and Evaluation, U.S. Environmental Protection Agency, Washington, DC, December 1989, p. xxxvi)

2100.  California study assumes a possible 4.6-foot sea level rise by 2100.  “A California report assumes a possible 4.6-foot rise by 2100, while the Dutch assume a 2.5-foot rise by 2050 in the design of their tidal gates.” (Rob Young and Orrin Pilkey, “How High Will Seas Rise? Get Ready for Seven Feet,” Yale Environment 360, January 14, 2010)


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Arctic Climate Change | Forest Fire Global Warming  | Global Warming Cost | Kilimanjaro Melting Glaciers | Heat Waves Climate Change | Energy Workforce Shortages | Water Scarcity
Global Warming Underestimated | China Global Warming | Climate Refugees |  Permafrost | Sea Level Rise | Rise in Sea Level MapsGlobal Warming Deaths 

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Rising Sea Levels