Now Is the Time to Consider Rising Sea Levels
November 29, 2017
The last few months have seen seemingly endless news coverage of hurricanes and their aftermath, most notably in Puerto Rico, where aid is still limited and many have been without power for months. But here in Cambridge, where we are separated from these storm-torn regions by miles of oceans and cities, it is easy not to see any cause for immediate concern. Even the dangers of climate change seem far away—worrisome, of course, but nothing demanding our immediate attention.
This couldn’t be further from the truth. The disasters in Puerto Rico and Texas should serve not as tragic tales of weather gone wrong, but as warnings for what the East Coast will see in the coming decades.
The fact that the Boston area is at risk due to climate change is nothing new—we’ve already seen the earliest consequences in a strange mix of heat waves, cold snaps, and unseasonably powerful storms. But as time goes by, with every year declared the hottest in recorded history, we must transition from identifying the cause to finding solutions. We know what we’ll be up against; in the coming decades, the oceans will rise like the temperatures, with sea levels projected to swell up to 38 inches by 2100. Low-lying islands could become almost entirely submerged, and, in a worst-case scenario, a meltdown of the Greenland ice sheet would raise sea levels a stunning 23 feet. Large portions of Boston and Cambridge are composed of landfill—covered tidelands that rise only a foot above today’s flood levels. Flood levels of 2050 could plunge those areas underwater, and the storms of 2100 would wash them away.
Other areas have already responded to these dangers, often following a disaster—a new system of levees in New Orleans after Katrina or a network of coastal barriers in the Netherlands—and these large investments have revealed themselves to be beneficial in the long run.
Some may argue that it’s silly to start construction now—even if we’re beginning to see the signs of climate change, they’re hardly unbearable. This is a foolish mindset; Boston researchers have calculated that a three-foot sea level rise would result in $1.4 billion in flooding damages—annually. Floods are responsible for more death and destruction than any other disaster in the United States. We’ve seen the consequences in a flooded Houston and crippled New Orleans, but we must now recognize not only what damage we could expect to see, but what damage we must prepare for, with the next Harvey, Irma, or Sandy just around the corner.
Seawalls are seen as the best option—a tried-and-true, if not old-fashioned, method. Four possible designs have been studied throughout Massachusetts, where uncontrolled sea level rises could harm an ocean-dependent economy. An inner harbor wall design is the most basic, albeit unsightly, seawall design, with a simple barrier that stretches from Logan Airport to Castle Island. An alternative outer harbor wall could seal off the area from Deer Island in Winthrop to the Hull Peninsula in the south.
The flashiest (and priciest) option would form a wall similar to that of the outer harbor barrier but with a dike system installed at an expanded Lovell’s Island. This latter option could prove the most effective in the long run by using existing natural foundations to hold back the water instead of an endless mass of concrete. The Boston Harbor is filled with natural undersea tide channels that allow water to be conducted throughout the bay with rising and falling tides, and these are vital to erosion prevention and maintenance of the coastal ecosystem. Climate change-fueled weather patterns could worsen these, leading to stronger storm surges and smaller beaches. Conversely, restrictions on water flow by the sapphire necklace wall could result in lower high tides and weaker storm surges, meaning less repairs and spills during hurricanes and floods.
It’s obviously not possible to simply wall off Boston from the ocean (though talk of drastic walls certainly filled the most recent presidential election), since we must maintain connections to shipping lanes and the bay’s diverse ecosystem. But any wall will have a high price tag—upwards of $10 billion, a price possibly worsened by difficult building conditions and time constraints.
In this case, we must argue not for saving money now, but for saving money, and potentially lives, in the future. After ten years of annual wall-free flooding, money that could have protected our cities will have been spent on cleanup and relief efforts.
Whether or not we will see the effects of climate change is not the issue—no amount of recycling and solar panels can prevent at least minimal sea level rise. We must now prepare for the changes we know will come. We cannot stop rising sea levels, but we can adapt to them, and, when our seawall is in place, face the coming storm.
This piece also appears in our November print edition.
