Ocean warming is putting coastal economies in trouble

Marine tourism and recreation supports greater than 320,000 jobs and goods and services valued at $13.5 billion in Florida. But in the summertime of 2023, when the water temperature off Miami reached as much as 37.8 degrees Celsius, a swim within the sea became significantly less attractive.

The way forward for some jobs and businesses across the ocean economy has also grow to be more uncertain as oceans warm and damage from storms, sea level rise and maritime heatwaves increases.

Sea temperatures were Warm up within the last century and Record highs last 12 months, mainly as a result of rising greenhouse gas emissions from the combustion of fossil fuels. Scientists estimate that greater than 90 % of the surplus heat attributable to human activities, was absorbed by the ocean.

This warming, hidden for years in data of interest only to oceanographers, now has profound consequences for coastal economies around the globe.

Understanding the role of the ocean within the economy is something I work on for greater than 40 years, currently at Center for the Blue Economy from the Middlebury Institute of International Studies. Mostly I study the positive contributions of the ocean, but that has began to vary, sometimes dramatically. Climate change has made the ocean a threat to the economy in some ways.

The dangers of sea level rise

One of the most important threats to the economy from ocean warming is rising sea levels. Water heats up, it expands. Together with the meltwater from glaciers and ice sheets, the thermal expansion of the water has led to increased flooding in low-lying coastal areas and the longer term of the island states at risk.

In the USA, rising sea levels will soon overwhelm Jean Charles Island in Louisiana and Tangier Island within the Chesapeake Bay.

Flooding at high tide, even on sunny days, is becoming more common, for instance in Miami Beach; Annapolis, Maryland; Norfolk, Virginia; and San Francisco. Flooding has greater than doubled since 2000 and is on the approach to tripling by 2050 along the country's coasts.

Maps show the rise in temperatures and sea levels, with the rise being fastest along the Gulf and Atlantic coasts and slower along the Pacific coast.
Satellite and tide data show sea level changes from 1993 to 2020.
National Climate Assessment 2023

Rising sea levels are also pushing saltwater into freshwater aquifers, that are used to supply water for agriculture. The strawberry harvest in coastal California is already affected.

These impacts are still small and localized. Much greater impacts are related to storms which might be amplified by rising sea levels.

Higher sea levels can worsen storm damage

Warmer ocean water fuels tropical storms. This is one in every of the explanation why meteorologists are warning of a severe hurricane season in 2024.

Tropical storms pick up moisture over warm water and transport it to cooler areas. The warmer the water, the faster the storm can form, the faster it could actually intensify, and the it could take longerleading to destructive storms and heavy rains that may flood cities even removed from the coast.

When these storms hit the already raised sea level, the waves and storm surge can dramatically enlarge the coastlines. flooding.

This is what the flooding from Hurricane Hugo in Charleston, South Carolina, would appear to be with today's higher sea levels.

Tropical cyclones caused greater than $1.3 trillion in damage within the United States from 1980 to 2023, with a median cost of $22.8 billion per storm. Much of this cost was borne by taxpayers.

It's not only tropical storms. Maine saw what can occur when a winter storm in January 2024 created tides 5 feet above normal which filled the coastal roads with sea water.

A firefighter walks through knee-deep sea water on a commercial street, with a sign for
A winter storm that hit the land during high tide caused water to flood the streets of Portland, Maine, in January 2024.
AP Photo/Robert F. Bukaty

What does this mean for the economy?

The potential future economic damage from sea level rise is unknown since the pace and magnitude of sea level rise are unknown.

According to at least one estimate, the prices of sea level rise and storm surges alone can be over $990 billion this century. Adaptation measures could only reduce these costs by 100 billion US dollarsThese estimates include direct property damage and damage to infrastructure akin to transport, water systems and ports. They don’t include impacts on agriculture as a result of the intrusion of saline water into aquifers, Agriculture.

Heatwaves within the sea cause difficulties for fisheries

Rising sea temperatures also affect marine life by causing extreme events called marine heatwaves and more gradual, longer-term temperature fluctuations.

In spring 2024, one third of the worldwide oceans Experience heat wavesCorals fight through their fourth global bleaching event in records, as warm ocean temperatures cause them to expel the algae that live of their shells and provides the corals color and food. While corals sometimes get better from bleaching, akin to Half of the world's coral reefs have died since 1950, and their The future after the center of this century is bleak.

A school of yellow-tailed fish swims over a reef in July 2023.
Healthy coral reefs provide breeding grounds and habitat for fish. These schoolmaster snapper fish were spotted at Davey Crocker Reef near Islamorada within the Florida Keys.
Jstuby/Wikimedia, From

The lack of coral reefs is greater than just their beauty. Coral reefs function breeding grounds and feeding grounds for hundreds of fish speciesAccording to NOAA estimates, about half of all federally managed fisheriesincluding snappers and groupers, rely upon reefs sooner or later of their life cycle.

Warmer waters cause fish to migrate to cooler areas. This is particularly evident in cold-water-loving species akin to lobsters, that are steadily moving north to flee warming seas. The once robust lobster fishery in southern New England is decreased significantly.

The map shows how the average locations of lobster, red hake and black sea bass have changed over 45 years, 1974-2019. Smaller diagrams show the respective changes
How three fish and shellfish species migrated off the U.S. Atlantic coast between 1974 and 2019. Dots show annual average location.

In the Gulf of Alaska, rising temperatures have nearly worn out snow crabs and shut down a $270 million fishery. completely closed for 2 yearsA serious heat wave off the Pacific coast spanned several years within the 2010s and affected fisheries between Alaska and Oregon.

That is not going to change anytime soon

The gathered ocean heat and greenhouse gases within the atmosphere are influence sea temperatures for hundreds of yearseven when countries reduce their greenhouse gas emissions to zero by 2050 as hoped. So while the oceans Temperatures vary from 12 months to 12 monthsThe overall trend is prone to proceed for at the least one other century.

There isn’t any cold water tap we are able to simply activate to quickly bring ocean temperatures back to “normal,” so communities might want to adapt while all the planet works to slow greenhouse gas emissions to secure the ocean economy for the longer term.

image credit : theconversation.com