Environmental News for a Healthier Planet and Life

Mangroves Threatened by Sea Level Rise Could Disappear by 2050

Mangroves Threatened by Sea Level Rise Could Disappear by 2050
Residents plant mangroves on the coast of West Aceh District in Indonesia on Feb. 21, 2020. Mangroves play a crucial role in stabilizing the coastline, providing protection from storms, waves and tidal erosion. Dekyon Eon / Opn Images / Barcroft Media via Getty Images

Mangroves play a vital role in capturing carbon from the atmosphere. Mangrove forests are tremendous assets in the fight to stem the climate crisis. They store more carbon than a rainforest of the same size.

However, they are under threat from sea level rise. A new study found that if emissions continue unabated, mangroves will not be able to keep up and could disappear in 30 years, as The Verge reported.

The new study published in the journal Science found that mangroves will start to die out if sea levels rise just six millimeters per year. However, mangroves are more likely to survive when sea level rise is less than 5 millimeters (about 0.2 inches) per year, which is projected for low-emissions scenarios this century, according to a Rutgers University statement.

"Under high-emissions scenarios, rates of sea-level rise on many tropical coastlines will exceed 7 millimeters per year, the rate at which we concluded there's a 6.2 percent probability mangroves can sustain growth," said co-author Erica Ashe, a post-doctoral scientist in the Department of Earth and Planetary Sciences at Rutgers University, in the statement. "The loss of these mangrove ecosystems could result in increased carbon dioxide in the atmosphere and fewer vital buffers against storm surges in the long run."

Around the world, there are 80 different species of mangrove trees. All of them grow in warm, shallow, coastal waters around the tropics. They spread their roots in sediment that is under the water, while their upper trunks, branches and leaves are above the water. The forests usually flood twice a day during high tide, according to Newsweek.

They play a crucial role in stabilizing the coastline, providing protection from storms, waves, and tidal erosion. Their root systems provide a habitat for fish and other animals, according to Newsweek. Mangrove forests work their magic by pulling freshwater from salty seawater to serve as a nursery for fish, crustaceans and shellfish. But if their roots are completely submerged for too long, the mangroves will drown.

As The Verge noted, mangrove forests are a boon to people and the planet, which is why scientists in Florida have sought to use mangroves as a defense for coastal communities from the ravages of the climate crisis. However, for mangroves to help us, we will first need to help them.

"We have an opportunity here to take action and to keep the rates of sea level rise below these critical thresholds, which is part of the reason that this is an important study," says Ashe, as The Verge reported.

To figure out just how much sea level rise was too much for the mangroves, Ashe and her colleagues, led by Neil Saintilan from Macquarie University in Australia, examined sediment core samples from 78 locations around the world. Those samples shed light on how mangroves responded to past changes in the rate of sea level rise, which went from more than 10 millimeters (0.39 inches) per year nearly 10,000 years ago to almost stable around 4,000 years later, as Newsweek reported. They discovered that mangrove ecosystems only developed when rates of sea level rise dropped below about 7 millimeters a year.

"There was good news and bad news. The good news was that mangroves were clearly capable of surviving much higher rates of sea-level rise than we have around the world at present," Saintilan told Newsweek. "There were many examples where mangroves were able to keep pace with sea-level rise of 5 millimeters per year; the current rate is just over 3 millimeters per year."

"However, there was little evidence that mangroves could keep pace with sea-level rise of over 7 millimeters per year, and this threshold was lower for mangroves on coral reef settings, which failed to keep pace with sea-level rise above 5 millimeters per year. If the rate of sea-level rise doubles, mangroves are in serious trouble," he added.

China's new five-year plan could allow further expansion of its coal industry. chuyu / iStock / Getty Images Plus

On Friday, China set out an economic blueprint for the next five years, which was expected to substantiate the goal set out last fall by President Xi Jinping for the country to reach net-zero emissions before 2060 and hit peak emissions by 2030.

Read More Show Less

EcoWatch Daily Newsletter

Trans Canada Trail and AccessNow partnership for AccessOutdoors / Trails for All project. Mapping day on Capital Pathway in Ottawa, Ontario with Camille Bérubé. Daniel Baylis

The Great Trail in Canada is recognized as the world's longest recreational trail for hiking, biking, and cross-country skiing. Created by the Trans Canada Trail (TCT) and various partners, The Great Trail consists of a series of smaller, interconnected routes that stretch from St. John's to Vancouver and even into the Yukon and Northwest Territories. It took nearly 25 years to connect the 27,000 kilometers of greenway in ways that were safe and accessible to hikers. Now, thanks to a new partnership with the Canadian Paralympic Committee and AccessNow, the TCT is increasing accessibility throughout The Great Trail for people with disabilities.

Read More Show Less


A lone house is seen inside the exclusion zone near the Fukushima Daiichi Nuclear Power Plant on February 26, 2016 in Namie, Fukushima, Japan. Christopher Furlong / Getty Images

By Kiyoshi Kurokawa and Najmedin Meshkati

Ten years ago, on March 11, 2011, the biggest recorded earthquake in Japanese history hit the country's northeast coast. It was followed by a tsunami that traveled up to 6 miles inland, reaching heights of over 140 feet in some areas and sweeping entire towns away in seconds.

Read More Show Less
Rescript the Future is WaterBear's global script writing competition focused on building a better future. WaterBear

"Watch. Connect. Take Action."

These words are the invitation and mandate of the WaterBear Network, a free film-streaming platform that launched in November of 2020. Its goal is to turn inspirational images of the natural world into actions to save it.

Read More Show Less
The Sunrise Movement launched its "Good Jobs for All" campaign that guarantees a good job to anyone who wants one and puts the country on a path toward a Green New Deal. Image Source / Getty Images

By Kenny Stancil

Amid the ongoing climate emergency and the devastating coronavirus pandemic that has resulted in more than 500,000 deaths in the U.S. alone as well as an economic meltdown that has left millions of people unemployed, the Sunrise Movement on Thursday launched its "Good Jobs for All" campaign to demand that lawmakers pursue a robust recovery that guarantees a good job to anyone who wants one and puts the country on a path toward a Green New Deal.

Read More Show Less