Tuesday, December 13, 2016

Puerto Rico: a “canary in the coal mine” for climate change

[Northwestern] In Alexi Correa’s coastal town of Loiza, Puerto Rico, families are raising their furniture on milk crates and building second floors onto their concrete homes to adapt to frequent flooding caused by sea level rise. They are witnessing a major impact of climate change right at their doorsteps.
“Our community is quite scared. We’re not sure what’s going to happen on a day-to-day basis and not quite sure what is going to happen to our houses or the area if the erosion keeps coming,” said Correa, one of Loiza’s community leaders.
Since 2010, the average sea levels around the island have increased at a rate 10 times faster than the historical rate—an increase of about 1 centimeter (0.4 inches) per year. While the change might seem small, the resulting coastal erosion has caused significant property damage and flooding.
In Loiza, a community on the outskirts of San Juan, large sections of the town have fallen into the sea, including a road, a grove of trees, and much of the community’s beachfront park. There is a 5- to 7-foot vertical drop off between the town’s sidewalk and the beach area due to erosion.
Scientists around Puerto Rico have been quick to address the changes occurring on the island, especially because people near the shore are already dealing with the consequences. Maritza Barreto and Rafael Méndez Tejeda, researchers at the University of Puerto Rico, saw Correa voicing his concerns on television and decided to investigate the changes occurring on the coastline.
“When we saw him, we decided to do something. We’re trying to figure out what’s happening because we fear for the people who live close by,” said Barreto, a professor of geomorphology. “Their houses could be destroyed.”
“We feel that the islands are like a canary in the coal mine,” said environmental engineer Ernesto Díaz. “Sadly, nature has been doing part of the job for us,” because now, he can point to tangible changes on the island to show the impacts of coastal erosion and sea level rise in addition to showing his scientific models and charts, he said.
The team visits research stations each month to collect samples of sand, which they analyze to determine the sediment composition. This allows the researchers to determine the origin of the sand – from the sea or the land – and measure the coastal erosion at the beach. On a field visit to Loiza, Méndez Tejeda pointed to the trees that had fallen within the past two years because of erosion.
“This tree was about 40 years old, which implies the beach was not like this 40 years ago,” Méndez Tejeda said. “There’s a reason why I came to this community—because it’s a real community, not just hotels and buildings, and no one was helping them. This is the human impact [of climate change].”
For coastal communities like Loiza, the beach is often where people gather during weekends and celebrations. But due to the erosion caused by the rising seas, the beaches are quickly disappearing. Read More