The MapBiomas study didn’t establish the extent to which Brazil’s retreating water resources resulted from natural causes. But experts have warned human activity is affecting global weather patterns, causing more frequent extreme events such as severe droughts and floods. The cutting and burning of forest, construction of large hydroelectric plants and dams or reservoirs for crop irrigation, all contribute to shifting natural patterns, said Mazeika Patricio Sullivan, an ecology professor at Ohio State University.
“We’re altering the magnitude of those natural processes,” said Sullivan, a wetlands expert who has studied water systems in the US, South America, Eastern Europe, and the Caribbean. “This is not just happening in Brazil, it’s happening all over the world.”
Sullivan said the MapBiomas data was “eye-popping”, though unsurprising; nearly 90 per cent of South America’s wetland area is estimated to have vanished since 1900, and nearly 40 per cent in North America, he said. Wetlands are essential to many species of wildlife and key to retaining water to be gradually released into rivers, which prevents flooding.
In Brazil’s Amazon rainforest, water that evaporates then travels on air currents to provide rainfall far afield. But some climate experts argue that the Amazon is headed for a “tipping point” in 10 to 15 years: if too much forest is destroyed, the Amazon would begin an irreversible process of degradation into tropical savanna.
There are more immediate sources of alarm, like possible power rationing this year. Hydroelectric reservoirs have been drained by a decade of lower-than-usual rainfall. Reservoirs in the Parana River basin, which powers the metropolis Sao Paulo and several states, have never been so depleted, the grid operator said this month.
The Parana River runs from Brazil into Argentina and along its course are the iconic Iguazu Falls at the border of the nations; the majestic cascades were unrecognisable for a few days in June, having dwindled to a trickle. The Parana waterway and its aquifers supply fresh water to some 40 million people, and a livelihood for fishing communities and farmers.
Brazilians Energy Minister Bento Albuquerque on August 25 called a press conference to deny the possibility of rationing, while at the same time calling on companies and people to reduce power consumption. Some analysts have speculated the dismissiveness is politically motivated ahead of an election year.
“At the current rate, blackouts are likely to happen this year, especially during peak hours,” said Nivalde de Castro, coordinator of the electricity sector studies group at the Federal University of Rio de Janeiro.
The declining water resources also risk exacerbating fires that people often set during the Southern Hemisphere’s winter to clear pasture, which then rage out of control.
Last year, more than one-quarter of Brazil’s Pantanal went up in flames. It was by far the worst annual devastation since authorities started keeping records in 2003.
The Pantanal has strong capacity to regenerate if given the opportunity to do so without repeated burning events. A surge of fires in the past week stirred concern among locals.
“Once again, the spectre of fires is back,” said Angelo Rabelo, president of a local environmental group that oversees a protected area of about 300,000 hectares. Last year, 90 per cent of his land was damaged by blazes.
Researchers at the State University of Mato Grosso found parts of the Pantanal in 2019 had 13 per cent more days without any precipitation compared to the 1960s. Jibing with the MapBiomas study, their findings also showed the marshes were losing surface water.
“The scenario is even worse this year: drier, and with less water,” Rabelo said from Corumba, a municipality in Mato Grosso do Sul state.
For Rabelo and others, last year’s fires were a wake-up call. He formed a full-time private fire brigade of seven people — the Pantanal’s first. They are better trained and have so far been able to respond faster, before fires spiral out of control.
But fresh challenges lie ahead. In areas without roads, navigation on smaller rivers can become problematic due to low water levels, Rabelo said. That means firefighters could soon have trouble reaching some blazes and, even if they can, less water available to extinguish them.
“The integration of water loss and wildfires: that’s a big issue that we need to start thinking more about,” said Sullivan.