Climate changes and the local environment:
For decades, global warming has increased sea levels in most coastal regions. Glacial meltwater has poured into the oceans, while warming water has expanded, taking up more volume and therefore sending sea levels ever higher.
Communities at risk of major tropical cyclones - such as Galveston county, Texas - have faced the full consequences of these changes to the world's oceans. Hurricanes are fueled by warm, moist air rising from warm water. The warmer the water, the more fuel hurricanes can use. While global warming has likely not increased the frequency of hurricanes overall, it has increased the frequency of exceptionally severe storms. Currently, powerful hurricanes are up to 11% stronger and more dangerous for communities such as Galveston.
A hurricane's winds usually cause the greatest damage to human infrastructure by pushing ashore enormous quantities of water. These "storm surges" are highest in powerful hurricanes, which means that they are more frequently destructive now than they have been. Off Texas, rising sea levels have made them even worse. Between 1957 and 2011, sea levels off Galveston rose by just over a foot, which has greatly increased the damage that will be inflicted to the county in a major hurricane.
How we know:
This information is derived from the National Oceanic and Atmospheric Administration (NOAA) study that connects global warming and hurricanes. It also draws from easy to use tools that are available online: the NOAA State Annual and Seasonal Time Series, and the NOAA Tides and Currents resource.
NOAA’s GFDL study on Global Warming and Hurricanes pulls data from published articles regarding hurricane intensity and temperature fluctuations since the 1800s. NOAA’s State Annual and Seasonal Time Series is derived from the current U.S. Climate Division Database that pulls data from temperature stations. NOAA’s Tides and Currents produces sea level trends measured from U.S. and Global Stations without the regular seasonal fluctuations due to coastal ocean temperatures, salinities, winds, atmospheric pressures, and ocean currents.
Galveston became a major U.S. commercial center and one of the largest ports in America during the 19th century. Whenever a major hurricane hits the county, its lack of a sustainable drainage system leaves many of its streets inundated with water for weeks. Without adequate flood safety measures, today 320,000 people are forced to evacuate from their homes at the approach of a hurricane. When these people are displaced and Galveston’s port is flooded, millions of dollars in goods from the commercial port are lost. Thousands of businesses around the United States that receive imported materials through this port are also impacted.
Because Galveston County has long had a major commercial port, it has a great deal of infrastructure that is vulnerable to hurricanes. In 1900, it endured the deadliest natural disaster in American history, when the 15-foot storm surge of the Galveston Hurricane killed up to 12,000 people. In 1970, Hurricane Celia, a Category 4 storm, came ashore near Galveston and inflicted nearly $6 billion of damage in 2017 USD. Then, in 2017, Hurricane Harvey inflicted $23 billion worth of property damage in Harris and Galveston counties alone.
Galveston County is extremely vulnerable to intense hurricanes, increasing local temperatures, and rising sea levels. As hurricanes strengthen and sea levels rise, the county may be hard pressed to survive the twenty-first century.
Article author: Kiera McCrane, Georgetown University
Article editor: Dr. Dagomar Degroot, Georgetown University