Guest essay by Eric Worrall
Sea Level Rise may displace up to 16 million Americans by 2100, according to researchers from the University of Georgia. But the study ignores history, technological progress, and the unreliability of climate models.
Sea level rise projected to displace 13 million in U.S. by 2100
A new study by University of Georgia researchers could help protect more than 13 million American homes that will be threatened by rising sea levels by the end of the century.
It is the first major study to assess the risk from rising seas using year 2100 population forecasts for all 319 coastal counties in the continental U.S. Previous impact assessments use current population figures to assess long-term effects of coastal flooding.
The study is based on analyses by Mathew Hauer for his doctoral work with the UGA Franklin College of Arts and Sciences; Deepak Mishra of the UGA department of geography; and Jason Evans, a former UGA faculty member now with Stetson University. It was published March 14 in the journal Nature Climate Change.
Based on year 2100 population forecasts, the authors report that a 6-foot sea level rise will expose more than 13 million people to flooding and other hazards from rising seas. Florida faces the most risk, where up to 6 million residents could be affected. One million people each in California and Louisiana also could be impacted.
Adaptation strategies are costly, and these are areas of especially rapid population growth, so the longer we wait to implement adaptation measures the more expensive they become,” Hauer said.
The abstract of the study;
Millions projected to be at risk from sea-level rise in the continental United States
Sea-level rise (SLR) is one of the most apparent climate change stressors facing human society1. Although it is known that many people at present inhabit areas vulnerable to SLR2, 3, few studies have accounted for ongoing population growth when assessing the potential magnitude of future impacts4. Here we address this issue by coupling a small-area population projection with a SLR vulnerability assessment across all United States coastal counties. We find that a 2100 SLR of 0.9 m places a land area projected to house 4.2 million people at risk of inundation, whereas 1.8 m affects 13.1 million people—approximately three times larger than indicated by current populations. These results suggest that the absence of protective measures could lead to US population movements of a magnitude similar to the twentieth century Great Migration of southern African-Americans. Furthermore, our population projection approach can be readily adapted to assess other hazards or to model future per capita economic impacts.
Obviously anyone in immediate danger of flooding needs to address the problems they face. But is it really wise to spend large sums now, to protect property against a future rise in sea level, which might never happen?
Sea level rise has not accelerated, as climate models predicted. Until climate models demonstrate reliable predictive skill, it would be unwise to use them as the justification for large expenditures of public money.
Even if the predicted sea level rise occurs, every year that preparations are delayed, substantially reduces the real economic cost per capita of action. Our economic, our engineering capabilities are growing geometrically. For example, new construction systems, such as gigantic “concrete printers“, robotic machines which create large continuous structures using scaled up 3d printing technology, are already being prototyped. Such robotic machines will dramatically cut the cost of building sea defences, when they become mainstream.
New York City has been able to keep up with sea level rise since it’s beginnings with simple technology, there is no reason to think future inhabitants won’t be able to.