Preface. It’s not just sea level rise, but increased precipitation, sinking land, hurricanes, and dam failures that will cause more floods in the future.

Dams will fail more often in extreme rain as at least half are older than their lifespan. In 2017 the Oroville Dam crisis in California forced more than 180,000 residents to evacuate after a spillway failure caused by massive rainfall. This is a good example of how existing infrastructure is already vulnerable to flooding.

The east coast is sinking, a hangover from the past weight of glaciers in the last ice age, increasing flooding. The San Francisco Bay Area is sinking too.

And as carbon levels rise, plants absorb less water from the air, allowing more rainfall to reach rivers and streams, increasing their flooding potential (Retallack 2020).

See “flooding in the news” at the end of this post for details.

Alice Friedemann   www.energyskeptic.com  author of “Life After Fossil Fuels: A Reality Check on Alternative Energy”, 2021, Springer; “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer and “Crunch! Whole Grain Artisan Chips and Crackers”. Podcasts: Derrick Jensen, Practical Prepping, KunstlerCast 253, KunstlerCast278, Peak Prosperity , XX2 report

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Davenport FV, Burke M, Diffenbaugh NS (2021). Contribution of historical precipitation change to US flood damages. Proceedings of the National Academy of Sciences.

Intensifying precipitation contributed 36% of the financial costs of flooding in the United States over the past three decades from 1988 to 2017, totaling almost $75 billion of the estimated $199 billion in flood damages from 1988 to 2017.

Flooding in the news (from ScienceDaily)

• 2021 Climate change puts hundreds of coastal airports at risk of flooding: 269 airports are at risk of coastal flooding now.  A temperature rise of would lead to 100 airports being below mean sea level and 364 airports at risk of flooding. If global mean temperature rise exceeds this then as many as 572 airports will be at risk by 2100
• 2021 Research confirms increase in river flooding and droughts in US, Canada, describes changes in extreme streamflow since 1910: Snowmelt runoff has resulted in extreme flooding, as well as extreme rain in drought-prone regions of the western and SE U.S. in summer and fall.

Since California provides a third of U.S. food and exports food world-wide, rainfall variability and less snowpack will impact non-Californians:

• 2020 Scientists predict dramatic increase in flooding, drought in California: California may see a 54% increase in rainfall variability by 2100.  
• 2020 More rain and less snow means increased flood risk: As the world warms and precipitation that would have generated snowpack instead creates rain, the western U.S. could see larger floods

• 2018 Sinking land will exacerbate flooding from sea level rise in Bay Area. Subsidence combined with sea level rise around San Francisco Bay doubles flood-risk area: Hazard maps use estimated sea level rise due to climate change to determine flooding risk for today’s shoreline, but don’t take into account that some land is sinking. A precise study of subsidence around San Francisco Bay shows that for conservative estimates of sea level rise, twice the area is in danger of flooding by 2100 than previously thought. And in King tides and 100-year storms, the water level will rise even higher
• 2018 Houston’s urban sprawl increased rainfall, flooding during Hurricane Harvey
• 2017 USA threatened by more frequent flooding. The East Coast of the USA is slowly sinking into the sea: the states of Virginia, North Carolina, and South Carolina are most at risk. Cities such as Miami on the East Coast of the USA are being affected by flooding more and more frequently. The causes are often not hurricanes with devastating rainfall such as Katrina, or the recent hurricanes Harvey or Irma. On the contrary: flooding even occurs on sunny, relatively calm days. It causes damage to houses and roads and disrupts traffic, yet does not cost any people their lives. It is thus also known as ‘nuisance flooding’.  And this nuisance is set to occur much more frequently in the future.
• 2018 Dramatic increase in flooding on East coastal roads:  High tide floods, or so-called “nuisance flooding,” that happen along shore roadways during seasonal high tides or minor wind events are occurring far more frequently than ever before. In the past 20 years roads along the East Coast have experienced a 90% increase in flooding — often making the roads in these communities impassable, causing 100 million hours of delays rising to 3.4 billion hours by 2100, as well as stress, and impacting transportation of goods and services.
• 2017 Flooding risk: America’s most vulnerable communities: Floods are the natural disaster that kill the most people. They are also the most common natural disaster.

References

Retallack G et al (2020) Gregory Retallack et al. Flooding Induced by Rising Atmospheric Carbon Dioxide. GSA Today. DOI: 10.1130/GSATG427A.1