Preservation In The Time Of Climate Change

http://blog.ucusa.org/the-future-of-historic-places-and-climate-change-686

Flooded City Dock
Annapolis, Maryland
flickr.com

Hello Everyone:

When we last spoke on Wednesday October 22, we discussed climate change going mainstream in urban planning.  Over the summer, we looked at climate change and historic places.  Now that autumn is upon us, yours truly would like to revisit the subject of historic places and climate change.  Today we have a blog post by Adam Markham, director for Climate Impacts Initiative, titles "The Future of Historic Places and Climate Change" for The Equation and originally appeared on the Preservation Leadership Forum Blog.  Mr. Markham looks at the future of historic places and can be done to save them from flooding, super storms, intense heat, and other natural disasters.

Boat patrol in Annapolis, Maryland
nnhs65.com

Admittedly the image of people in boats, rowing down the streets of Annapolis, Maryland looks a little odd but this past August the city experienced extreme flooding, the result of severe storms.  This extreme flooding, "nuisance" flooding, is not something completely unfamiliar to the Chesapeake Bay region. "Nuisance" floods overwhelm storm at the rate of ten times more than they did fifty years ago.  What is a "nuisance" flood?  The definition of a "nuisance" flood varies, depending on the slope of the shoreline and the presence of any man-made barriers.  (http://articles.baltimoresun.com/...bs-md-annapolis-baltimore-flooding-study-20...)  Mr. Markham reports, "Sea level rise and costal flooding exacerbated by extreme rainfall events and storms, is perhaps the most obvious threat to our heritage..."  The City of Annapolis, supported by the NTHP, has identified 140 historic buildings threatened by flooding, and the growing risk to historic districts along American coastlines.  As global warming continues, changing the climate, the affects for historic buildings, archeological sites, and cultural landscapes become more desperate.

Man looking at flooded parking lot on Dock Street
chesapeakebay.net

Adam Markham reports, "The global average of sea level rise was about 8 inches between 1880 and 2009, a period during which the planet warmed by 1.8 degrees F.  As water warms, it expands, and this combined with the melting of land ice including glaciers and polar ice sheets causes sea levels to rise." It is those rising sea levels that present the biggest threat to historic structures in coastal communities.  "Higher seas mean more frequent and severe tidal flooding, increased rates of coastal erosion, and greater storm damage."  A new report from the Union of Concerned Scientists analyzed 52 National Oceanic and Atmosphere Administration tide gauges along the East and Gulf coast, demonstrating that many of the low-lying communities will experience double or triple the amount of high-tide flooding in the fifteen years.  The full study is available at http://www.ucsusa.org/sites/default/files/attach...encroaching-tides-full-report.pdf

Sveinn Storm drains water out of ice cream store
lubbockonline.com

You really do not need to be a climate change expert to understand the risk flooding poses to historic waterfront districts from St. Augustine, Florida through Norfolk, Virginia.  Charleston, South Carolina, already one of the leaders in historic preservation experiences annually experiences about ten high-tide flooding events, compared to the mere two events in the seventies and the situation is getting worse.  Some cities, including portions of Washington D.C. and Annapolis, can expect to undergo 150 to 200 flooding events yearly by 2030.  Shocking statistic. Storms (Mr. Markham does not distinguish the level of severity) on make the threat of floods worse.  One example, the United Sates Naval Academy, famous for its Beaux-Arts period buildings, sustained $120 million in flood damage from Hurricane Isabel in 2003.

Flooding from Hurricane Isabel
September 22, 2003
U.S. Naval Academy
usna50.8k.com

It is not just the East and Gulf Coasts that are in danger, it is other historic coastal communities throughout the United States.  Another example, early Hawaiian sacred sites and prehistoric fish-traps on the west coast of the Island of Hawai'i are in peril, as are shell mounds on the wetlands of southern Florida, colonial districts in Baltimore and Boston, the Gay Head Lighthouse on Martha's Vineyard, and the very first colonial settlement in the United States, Jamestown, Virginia.  This past June, Adam Markham participated in climate change round table with American Secretary of Interior Sally Jewell in Jamestown and was struck by the growing threat of flooding facing this seventeenth century settlement.  During the day, Secretary Jewel toured the first site of English manufacturing and had this to say,

It' very clear we have global warming and sea level rise and this is a hot spot for it...And what's risk is the history of our country...We don't have very many places in the United States that talk about the super-early history of settlers connecting with the native people of the land, so this is a really important place."

Jamestown, Virginia
boxwoodinn.com

Even though threat of flooding from rising sea level to historic coastal communities is obvious, it is also important to point out the less considered impact of climate change on inland historic sites.  Wildfires are a growing menace to historic sites in the west, from the pueblo ruins of Bandelier National Monument to the Gold Rush towns of Groveland, California and Virginia City, Nevada.  In May of this year the UCS published a report, National Landmarks at Risk, which you can find at http://www.ucsusa.org/sites/.../National-Landmarks-at-Risk-Full-Report.pdf  The more intense hot and dry conditions have been the main engine behind the growing number of areas destroyed by wildfires in the western states.  Further, said conditions have prolonged wildfire season by two months since 1970, followed by flash floods in areas devoid of trees and vegetation, placing in danger archeological resources in the Southwest.

Mission at San José at Tumacácori
Arizona
nps.gov

Adam Markham reports, "According to the 2014 National Climate Assessment (NCA), there has been a strong trend toward increasing frequency of extreme rainfall events nationwide in recent years."  The heavy rainfall has been identified by the National Park Service "as a risk factor for abode structures such as the Mission at Tumacacori in Arizona while flash floods associated with Hurricane Irene in 2011 brought damage and destruction to many historic covered bridges in upstate New York and Vermont."  The Northeastern states have also experienced greater extreme rainfall events since 1958, more than any region in the United States-a 70 percent increase to be specific.

Bandelier National Monument
New Mexico
en.wikipedia.org

Less dramatic but equally insidious climate change affect are alterations in the freeze-thaw cycle.  One case in point is the alarm raised by the managers of Augustus Saint-Gaudens's house, Aspet, in New Hampshire over the damage done to the brickwork from warmer winters.  In the past, the snow stayed on the ground throughout winter, now it melts before falling again and the repeated freeze-thaw cycles are causing the brickwork to splinter and shear.

This just some of the case studies of how climate change affects historic sites.  Like Adam Markham, yours truly also finds alarming to consider that for a country so steeped in history, Americans very little understanding of just how perilous the situation is for historic sites at risk or under immediate threat. One of the solutions Mr. Markham proposes is reduction in greenhouse gas emissions.  This is the most apparent solution but one that needs to be addressed immediately, not just in the immediate future but also in the long-term to keep the problem from worsening in future decades.  Mr. Markham calls for climate resilience to become a national priority.  He suggests, "...we must allocate the necessary resources to ensure effective preservation in the changing climate.  One that will require a better understanding of which resources are most vulnerable to climate impacts and how climate change is increasing the risks."  Mr. Markham also recommends evaluating "...the effectiveness of current preservation strategies and technologies in light of these rapidly changing environmental factors.  And significantly, we must find ways to prioritize among at-risk sites given limited available resources."  The bottom line, the longer we delay addressing these matters, the more likely we will regret it.