U.S. national parks are at risk from climate change, and people need to take action to protect them, said Brendan Cummings, director of conservation at the Center for Biological Diversity, a nonprofit organization dedicated to protecting endangered species.
From coast to coast, in 63 iconic parks, visitors can see towering waterfalls, scenic hot springs and giant sequoias in landscapes that range from swamp to desert.
Landscapes are under stress, and climate change is exacerbating the situation, Garrett Dickman, a forest ecologist at Yosemite National Park, told VOA.
Scientists warn that if warming continues at its current rate, much of the park’s wildlife and vegetation is at risk of extinction by the end of the century.
“Climate change is the greatest threat national parks have ever faced, … [ they] is warming twice as fast as the rest of the country,” the National Parks Conservation Association reports on its website.
Across the country, one of the biggest problems is water, sometimes too much, causing floods, or too little, causing drought and fires.
Yellowstone National Park in the western United States is known for its wildlife, sparkling hot springs, and beautiful mountain ranges.
It has also been ravaged by climate change.
Record rainfall fell in the park over four days in June. Together with the already rapidly melting snow cover, the rain caused catastrophic flooding and landslides that washed away river banks and destroyed bridges.
“Historically, Yellowstone hasn’t had a lot of flooding,” and there was no warning that this level of flooding was coming, said Cam Scholey, the park’s superintendent.
Cathy Whitlock, a climate change expert at Yellowstone, explained, “There was a lot of snowfall late in the season, with excessive rain on top of the snowpack, and instead of soaking the ground, it ran into rivers.”
As the park gets warmer, she said, “there’s more precipitation in the winter and then very dry summers, which leads to more frequent wildfires.”
The destruction of trees affects the ecosystem.
“We’re not going back to the same trees that were burned, and some areas that were once forested are becoming scrub or grassland,” Whitlock said.
Climate change is also affecting wildlife.
“Cold-water fish are heading to colder streams at higher elevations, and grizzly bears are looking for additional food sources,” Whitlock said.
Yosemite National Park in California has granite cliffs, towering waterfalls and old trees.
In recent years, an increasing number of trees and bushes are dying from the intense heat.
“There have been more days this summer with temperatures over 100 degrees (37 Celsius) than in the past,” Dickman said. “The trees can’t get enough moisture to survive, and so they become weaker and more vulnerable to insects and disease.”
Dead vegetation adds fuel to the fire.
“We have big fires that are burning more than ever before, and we have areas that have turned into invasive grasses,” Dickman said. “In the lower elevations, we’ve lost at least 2.4 million trees.”
Climate change is also affecting the park’s giant sequoias, which can live up to 3,000 years.
They are very resilient, but have not adapted to modern fires, Dickman said. Although none of the trees in the park have died, he continued, they are showing drought stress.
Joshua trees in Joshua Tree National Park in the California desert are also struggling to survive as temperatures rise.
“I see a lot of dead Joshua trees that look like they died from drought or heat stress,” said Cummings, who lives near the park. Trees also die because rodents strip their bark for food when there is nothing to eat because it is very dry.
Trees that grow slowly do not recover quickly.
“It takes about 30 years for the trees to set seed, and very few grow to become a Joshua tree, maybe one in a thousand,” Cummings explained. Today, it is even more difficult for seedlings to survive in the harsh desert climate.
“We may need a plan to grow seedlings at higher and cooler altitudes,” he said.
The spectacular Grand Canyon in Arizona was carved by the 446-kilometer-long Colorado River.
“Due to the changing weather conditions, river flows are decreasing,” said Mark Nebel, the parks geosciences program manager. He said, “It’s affecting the groundwater that feeds our springs,” which wildlife relies on, as well as vegetation, causing mass die-offs of juniper, small trees that are relatively drought-tolerant.
The river is also used for agriculture and drinking water for millions of people in the Southwest.
“We’re taking too much water from the river,” he told VOA, “and we need to find ways to use less of it.”
In the southeastern United States, the Florida Everglades are a vast subtropical wetland ecosystem.
Sea level rise, which caused coastal erosion and flooding in southern Florida, also changed the Everglades.
“We’re seeing changes in the water chemistry, particularly the salt, and the soil elevation is dropping,” said John Kaminoski, an Everglades researcher and associate professor at Florida International University.
“Freshwater areas become more saline and salt marshes become freshwater,” he said, “and that can affect trees, mangroves and wildlife.”
Kaminoski said he hopes the Everglades will remain intact in the future, but water management is key.
“It’s a reality that we can never go back to the way things were before,” he said, “so we have to find ways to move forward in new ways.”