By CC Cunningham, Intern, Thomson Reuters Corporate Responsibility & Inclusion | 29 August 2016
On August 29th, 2005, the world tuned in to watch the full force of Mother Nature play out across their television screens. Early in the morning, all eyes were on New Orleans, Louisiana, as a Category 3 hurricane made landfall on the southeast coast of the state. With winds of up to 125 mph (200 km/hour) and a storm surge of up to 28 feet (8.5 m), Hurricane Katrina caused massive destruction along the Gulf Coast and claimed over 1,200 lives – making it the costliest and third deadliest hurricane in U.S. history. Due to defective infrastructure and poor planning, Katrina’s storm surge caused over 50 breaches to the levees surrounding New Orleans and flooded up to 80% of a city already below sea level. New Orleans has gradually recovered from the tragedies it once endured; however, a new threat now looms.
In 2012, Louisiana initiated their “Master Plan” for rebuilding and equipping its coastline with brand new infrastructure and security measures to ensure a natural disaster would not have the devastating impact as it did on a Katrina-sized scale. Utilizing $8.7 billion, the Louisiana government employed a task force to restore coastal wetlands, as well as rebuild the levees and floodways in such a way that would protect the city and the southern part of the state from future hurricanes and flooding.
In addition to a storm surge, these precautions were also designed to withstand a projected sea level rise of up to 17 inches. However, this falls short of the projections for global sea level rise, which exceed the height of the new levees by nearly 20 inches. In addition, scientists claim that climate change-driven ocean rise is already outpacing the designs of two major storm surge reduction structures in the city of New Orleans: the West Closure Complex and the Lake Borgne surge barrier. The Lake Borgne surge barrier was specifically designed to combat the storm surge of a hurricane that has a 1% chance of occurring – better known as a “100-year storm”. Standing at a height of 26 feet, the structure only includes an extra foot of height as a safeguard from any kind of sea level rise over the next 50 years, with scientific reports stating that the structure should be at least 39 feet above the current sea level.
Before Katrina touched down on land as a Category 3 hurricane, the storm raged over the Gulf of Mexico, where warmer sea surface temperatures (SSTs) caused it to double in size and strengthened it to a powerful Category 5 typhoon. According to the National Climatic Data Center report (2006), these SSTs in the Gulf were “one to two degrees Celsius above normal, and the warm temperatures extended to a considerable depth through the upper ocean layer.” As the hurricane passed over cooler water on its way toward the Gulf Coast, it died down to a Category 3 level. In August of 2005, the Gulf Coast had an average temperature of 30 degrees Celsius. Since then, the average SST of the Gulf has risen by 2 degrees Celsius, with an increasing number of experts saying climate change is to blame. What would happen today then, if the Gulf Coast was faced with another hurricane on a similar scale to Katrina?
As with the circumstances surrounding Hurricane Katrina, storms are weakened by colder, deeper ocean water – and strengthened by warmer water on the surface. However, if the deeper water is also warm, the storm will only grow stronger. As global warming of the planet continues to increase, future hurricanes will only gain more power before they reach land. This will facilitate weaker storms at their origin to grow in intensity and wreak havoc at landfall – meaning we don’t necessarily need a storm on par with Katrina to cause extensive damage. These occurrences will become more frequent and, as sea levels rise and gradually swallow up the delta of the Mississippi River, the Louisiana coast will subsequently lose the protection of the wetlands to dissipate storm surges, causing flooding and widespread damage further inland.
Looking towards the future, what can we do? The overarching (and more long-term) goal is cutting our global carbon footprint in order to stem the potentially devastating rise in sea levels around the world. By reducing our carbon emissions, we can slow the devastating effects of climate change and preserve our coastal cities. Unfortunately, however, significant ocean warming and sea level rise have already begun to take place worldwide. By mitigating the risk of natural disasters as a consequence of these climate events, we can preserve and protect our coastlines and the abundant wildlife, natural resources and human life that thrive there. The first step is addressing climate change and the dire impacts it has. By doing so, steps can be taken to build the proper infrastructure and protective measures to ensure our coastlines enjoy a prosperous future for many years to come.