30
There are uncertainties we have to deal with. How fast will sea-level rise in the
future? At present, in northeastern NC, sea level is rising at about 4 mm (0.15 inches)
each year, but it is accelerating. As melting of the Greenland ice sheet continues at
ever-increasing rates, and seawater expands as it heats, and with a contribution of
changes to ocean circulation patterns, sea level could easily rise by over 3 feet (1 m)
by the year 2100. This is a serious consideration for coastal counties, many of which
have an average elevation of approximately 2 feet (0.6 m). How will storm frequency and intensity be affected? Hurricanes derive their energy from very warm
surface ocean waters. Our data and those of other researchers suggest an increase in
hurricane activity during the warm surface ocean conditions of the Medieval Warm
Period. However, we are already exceeding the temperatures of that period. Models
and historical data suggest a recent increase in the number of intense hurricanes,
which will likely continue into the future, but it is not clear whether the total number
of hurricanes in a year will increase. What will be the impact on winds and precipitation in the region? This has significant implications for flooding, water for agriculture and people, wave energy and coastal erosion. Recent calculations indicate that
winter precipitation in eastern North America has increased as a result of the human
influence on climate.
How will humans respond and attempt to mitigate the impacts of climate change?
This is the most significant question. Will society accept that the current pattern of
change is real and will continue and accelerate, and make the difficult political and
economic decisions to stave off worst-case scenarios involving several meters of
sea-level rise? Or will we take a path of indifference that will commit our children
to the most extreme consequences. We understand, based on changes in the past,
what we might expect in the future, and we know that we must be prepared to deal
with the changes.
Acknowledgments I am forever grateful to the many students, both graduate and undergraduate,
who contributed to the knowledge expressed in this paper via their back-breaking work in the field,
and tedious hours in the laboratory. Many colleagues also contributed, most notably, Dr. Stephen
Culver, Dr. Stanley Riggs, Dr. Eduardo Leorri, Dr. Ryan Mulligan, Dr. Siddhartha Mitra, Dr. John
Wehmiller, Dr. Reide Corbett, Dr. J.P. Walsh, Dr. Ben Horton, Dr. Andy Kemp, Dr. Kathleen
Farrell, and Dr. Rob Thieler. Without funds to support this type of work, our knowledge would be
very limited. I would like to acknowledge funding from the U.S. Geological Survey, the National
Science Foundation, and the Cushman Foundation for Foraminiferal Research.
If You Would Like More Information
Culver S, Grand Pre C, Mallinson D, Riggs S et al (2007) Late Holocene Barrier Island Collapse:
Outer Banks, North Carolina, U.S.A. Sedim Rec 5:4–8
Donnelly JP, Woodruff JD (2007) Intense hurricane activity over the past 5,000 years controlled by
El Niño and the West African monsoon. Nature 447:465–468
Donnelly JP, Hawkes AD, Lane P, MacDonald D et al (2015) Climate forcing of unprecedented intense-hurricane activity in the last 2000 years. Earth’s Future. https://doi.
org/10.1002/2014EF000274
D. J. Mallinson
There are uncertainties we have to deal with. How fast will sea-level rise in the
future? At present, in northeastern NC, sea level is rising at about 4 mm (0.15 inches)
each year, but it is accelerating. As melting of the Greenland ice sheet continues at
ever-increasing rates, and seawater expands as it heats, and with a contribution of
changes to ocean circulation patterns, sea level could easily rise by over 3 feet (1 m)
by the year 2100. This is a serious consideration for coastal counties, many of which
have an average elevation of approximately 2 feet (0.6 m). How will storm frequency and intensity be affected? Hurricanes derive their energy from very warm
surface ocean waters. Our data and those of other researchers suggest an increase in
hurricane activity during the warm surface ocean conditions of the Medieval Warm
Period. However, we are already exceeding the temperatures of that period. Models
and historical data suggest a recent increase in the number of intense hurricanes,
which will likely continue into the future, but it is not clear whether the total number
of hurricanes in a year will increase. What will be the impact on winds and precipitation in the region? This has significant implications for flooding, water for agriculture and people, wave energy and coastal erosion. Recent calculations indicate that
winter precipitation in eastern North America has increased as a result of the human
influence on climate.
How will humans respond and attempt to mitigate the impacts of climate change?
This is the most significant question. Will society accept that the current pattern of
change is real and will continue and accelerate, and make the difficult political and
economic decisions to stave off worst-case scenarios involving several meters of
sea-level rise? Or will we take a path of indifference that will commit our children
to the most extreme consequences. We understand, based on changes in the past,
what we might expect in the future, and we know that we must be prepared to deal
with the changes.
Acknowledgments I am forever grateful to the many students, both graduate and undergraduate,
who contributed to the knowledge expressed in this paper via their back-breaking work in the field,
and tedious hours in the laboratory. Many colleagues also contributed, most notably, Dr. Stephen
Culver, Dr. Stanley Riggs, Dr. Eduardo Leorri, Dr. Ryan Mulligan, Dr. Siddhartha Mitra, Dr. John
Wehmiller, Dr. Reide Corbett, Dr. J.P. Walsh, Dr. Ben Horton, Dr. Andy Kemp, Dr. Kathleen
Farrell, and Dr. Rob Thieler. Without funds to support this type of work, our knowledge would be
very limited. I would like to acknowledge funding from the U.S. Geological Survey, the National
Science Foundation, and the Cushman Foundation for Foraminiferal Research.
If You Would Like More Information
Culver S, Grand Pre C, Mallinson D, Riggs S et al (2007) Late Holocene Barrier Island Collapse:
Outer Banks, North Carolina, U.S.A. Sedim Rec 5:4–8
Donnelly JP, Woodruff JD (2007) Intense hurricane activity over the past 5,000 years controlled by
El Niño and the West African monsoon. Nature 447:465–468
Donnelly JP, Hawkes AD, Lane P, MacDonald D et al (2015) Climate forcing of unprecedented intense-hurricane activity in the last 2000 years. Earth’s Future. https://doi.
org/10.1002/2014EF000274
D. J. Mallinson