For most people, climate change is not an immediate problem. They see it as a potential problem for future generations, so they take a step back and try to ignore the problem. However, the residents of coastal areas all around the world are slowly beginning to realize the risks of global climate change. For them, the future is already here, with rising water and massive floods happening almost every year. The problem, unfortunately, is expected to get worse.
A recent study shows that, by the year 2100, about 60 percent of coastal communities in the United States will experience some type of flooding caused by climate change, posing an immense risk for the Florida shoreline and local lake shorelines.
But what is the fix for this environmental problem? The easy answer is to just build tall seawalls or other barriers that simply stop the water. It's quite simple and straightforward, right?
Yes, barriers can be a quick fix for rising waters and can protect the coastal or lake shoreline. But barriers occasionally fail. And when they don't fail, they usually affect the very sensitive coastal ecosystems. This means they can harm the habitat, the plants, and animals that live in them.
The good news is – walls are not our only option. Fortunately, we have alternatives that can work and do work, if done properly. There are ways that help us avoid floods and rising waters, stop erosion and limit the damage caused by wave energy. Permeable pavements, for instance, are porous and allow floodwaters to seep below the surface, rather than creating pools.
With the advent of these new solutions, where do we go from here?
Soft Vs. Hard Defenses Against Rising Waters
The immediate fix for rising waters consists of a combination of seawalls and bulkheads (vertical walls that protect the shore but don't offer protection against waves) and revetments (sloping walls built on cliffs and banks). These two defenses are the most common solutions in providing protection against rising water across the United States.
Recent estimates show that about 14 percent of the continental United States has been “protected” against the water with these types of structures. The number is steadily rising and it's expected that about 32 percent of the coastline will have some type of protection by the year 2100.
There are, however, a few issues with these structures. Although they do protect the coastline, they don't dampen the wave energy. Instead, they deflect it to nearby areas. Simply put, these unprotected properties are now more prone to damage than ever before.
The structures are also sensitive to erosion, causing them to collapse. The main disadvantage is the negative effect these structures have on the coastal ecosystems. The Florida shoreline, for instance, is home to immense biodiversity which has to be protected and preserved. Usually, the poorly made coastal walls and revetments damage the ecosystems, destroy habitats and reduce the biodiversity near the sea and lake shorelines.
The alternative is also known as the soft defense against rising waters. These defenses are also known as living shorelines and involve technologies and techniques designed to help and preserve the delicate ecosystems. They are made from natural materials and are non-invasive. The components of these systems are site-specific:
Calm water shores – The best solution for these shores consist of water-absorbing salt marsh, fortified by ledges made of rocks or oyster shell bags; another alternative is logs made of natural coconut fibers.
Normal shorelines – These can be protected by mangroves, which have extensive roots deep into the mud, offering protection against rising waters.
Essentially, the soft defense creates a living protective wall that promotes the evolution of the coastal ecosystems. Creating a living shoreline is simple and involves the use of oyster and coral reefs in order to create simple breakwaters that dissipate the wave energy. In time, the new living shoreline becomes stable and the risk of collapse is non-existent. These structures naturally attract sediment and a new ecosystem is built, allowing plant and animal growth.
Recent data also suggests that soft defenses may be better alternatives to hard defenses. For instance, Hurricane Irene damaged about 76 percent of coastal bulkheads and seawalls in North Carolina. On the other hand, the coastal areas that were protected by marshes were not damaged at all. A similar situation was observed near the Florida shoreline area, where soft protection was more efficient than hard protection.
Living shorelines are awesome solutions against rising waters, but they are not ideal in all situations. For instance, for the protection of New York City, a mixed solution offers the best protection: a set of artificial protections together with natural ones will work successfully in case of powerful hurricanes. What's more, an already existing artificial structure can be enforced by natural components, making it more environmentally friendly. Over time, plants and sediments will grow on the structure, making it more friendly in the ecosystem. For instance, a nonprofit organization in Alabama is doing just that, with amazing success. The Alabama Nature Conservancy organization is installing square wire cages near the already existing concrete bulkheads. These structures create a slope of natural components that grow in time. It is estimated that in just a few years, the metal cages will be inhabited by animals and plants, creating new, viable ecosystems, while also offering protection for coastal communities.
The rising sea levels are a real problem across the globe, especially for coastal communities. Luckily, there are solutions, both soft and hard, or a combination of both. However, the real problem behind raising waters is climate change. The immediate solutions are clear – either artificial or natural, they do work. Climate change, on the other hand, is the main issue we should address, as a society. Unfortunately, we have less and less time to tackle it.
As climate change becomes more of a threat, incorporating these solutions and strategies into our conservation programs offers the best chance for us to protect and cultivate our quickly diminishing wildlife and shorelines.