The World’s Largest Tropical Wetland Has Become an Inferno
This year, roughly a quarter of the vast Pantanal wetland in Brazil, one of the most biodiverse places on Earth, has burned in wildfires worsened by climate change. What happens to a rich and unique biome when so much is destroyed?
The unprecedented fires in the wetland have attracted less attention than blazes in Australia, the Western United States and the Amazon, its celebrity sibling to the north. But while the Pantanal is not a global household name, tourists in the know flock there because it is home to exceptionally high concentrations of breathtaking wildlife: Jaguars, tapirs, endangered giant otters and bright blue hyacinth macaws. Like a vast tub, the wetland swells with water during the rainy season and empties out during the dry months. Fittingly, this rhythm has a name that evokes a beating heart: the flood pulse.
The wetland, which is larger than Greece and stretches over parts of Brazil, Paraguay and Bolivia, also offers unseen gifts to a vast swath of South America by regulating the water cycle upon which life depends. Its countless swamps, lagoons and tributaries purify water and help prevent floods and droughts. They also store untold amounts of carbon, helping to stabilize the climate.
For centuries, ranchers have used fire to clear fields and new land. But this year, drought worsened by climate change turned the wetlands into a tinderbox and the fires raged out of control. “The extent of fires is staggering,” said Douglas C. Morton, who leads the Biospheric Sciences Laboratory at the NASA Goddard Space Flight Center and studies fire and food production in South America. “When you wipe out a quarter of a biome, you create all kinds of unprecedented circumstances.” His analysis showed that at least 22 percent of the Pantanal in Brazil has burned since January, with the worst fires, in August and September, blazing for two months straight.
Naturally occurring fire plays a role in the Pantanal, in addition to the burning by ranchers. The flames are usually contained by the landscape’s mosaic of water. But this year’s drought sucked these natural barriers dry. The fires are far worse than any since satellite records began.
The Brazilian federal police are investigating the fires, some of which appear to have been illegally targeting forests.
Because ecosystems are interconnected, the well-being of the wetland is at the mercy of the booming agriculture in the surrounding highlands. The huge fields of soy, other grains and cattle — commodities traded around the world — cause soil erosion that flows into the Pantanal, clogging its rivers so severely that some have become accidental dams, robbing the area downstream of water.
But perhaps the most ominous danger comes from even further afield: climate change. The effects that models have predicted, a much hotter Pantanal alternating between severe drought and extreme rainfall, are already being felt, scientists say. A study published this year found that climate change poses “a critical threat” to the ecosystem, damaging biodiversity and impairing its ability to help regulate water for the continent and carbon for the world. In less than 20 years, it found that the northern Pantanal may turn into a savanna or even an arid zone. “We are digging our grave,” said Karl-Ludwig Schuchmann, an ecologist with Brazil’s National Institute of Science and Technology in Wetlands and one of the study’s authors.
To save the Pantanal, scientists offer solutions: Reduce climate change immediately. Practice sustainable agriculture in and around the wetland. Pay ranchers to preserve forests and other natural areas on their land. Increase ecotourism. Do not divert the Pantanal’s waters, because its flood pulse is its life.
Adapted from: https://www.nytimes.com/2020/10/13.
