The drought and heatwaves that seared eastern Australia in the lead-up to the 2019-20 black summer bushfires killed as much as 60% of the trees in some areas that escaped the fires.
While Australian species are typically hardened to extreme conditions, the record heat and dryness of 2019 pushed some common tree varieties beyond their thresholds, potentially threatening whole ecosystems if they don’t grow back.
The widespread loss of often common species could trigger the transformation of ecosystems from forests to woodlands, or woodlands to scrublands.
The potential change of tree species could have far-reaching effects because such shifts would alter the availability and seasonality of food resources for insects, birds and other species.
Across the region, the price of historic dryness is being measured in lost crops, a slowdown in mining, surging transportation costs and shortages of energy in a region heavily dependent on hydropower.
Chile, is caught in the vortex of a 13-year drought, its longest and most severe in 1,000 years. The government has declared an agricultural emergency in 8 of its 16 regions and is offering aid to stricken farmers. Some regions are registering rainfall losses of between 62 and 80%.
Bolivia’s drought is lingering after two brutally dry years that saw millions of acres burned by wildfires.
The worst drought in nearly a century is forming in parts of Brazil. The Paraná River — one of the principal trade routes in South America’s Southern Cone, second on the continent only to the Amazon in length and flow — has been reduced in some stretches to a stream.
Total cereal output in Argentina was 12.7 million tons in 2020. The number is expected to fall to 11.4 million in 2021 and 10.9 million in 2022, according to the U.N.’s Food and Agriculture Organization. In the longer term, the World Bank warns, changes in weather patterns could cause corn and wheat yields in some parts of the country to fall by 80%.
Analysts fear the droughts are a harbinger of a new normal, portending consistently lower crop yields in the future.
Unusually powerful sandstorms have left at least six people dead in Sao Paulo in recent weeks, local media said, as southeastern Brazil grapples with severe drought.
Scenes of huge orange dust clouds rumbling across the countryside—with winds of up to 100 kph (62mph)—have been seen at least three times since the end of September, terrifying residents in urban and rural areas of Sao Paulo and Minas Gerais states.
Brazil is facing its worst drought in 91 years, which has led to a critically low water level in hydroelectric reserves in the central-western and southern parts of the country, driving up electricity costs.
“In this century, every year has had record temperatures. There is more heat in the atmosphere, which has just been transformed into energy for extreme (weather) events: rain, storms, floods, but also drought, cold and heat, what has just been unleashed with events like these dust storms”.
The southern Murray-Darling Basin occupies the southern half of NSW and northern Victoria. It receives most of its water from rain in the cooler months that fills dams, with any overflow spilling into the floodplains.
The Murrumbidgee River catchment is approximately 84,000 square kilometres, or about 8% of the basin. It encompasses a complex series of wetlands and floodplains.
The height of the Murrumbidgee River—the third longest in Australia and highly valued for irrigation and hydro-electricity—has dropped by about 30% during the growing season. This is a loss of approximately 300 million litres per day.
The findings follow a major report the Intergovernmental Panel on Climate Change released on Monday, which found much of Australia will become more arid as the world warms. This will bring reduced river flows, mass tree deaths, more droughts and drier soils.
Given this drop is associated with the wettest months from April to September, the outlook for the warmer months between October and March is dismal. The number of days when the river ceases to flow will certainly increase.
Dam building and excessive irrigation are often behind decreased river flows across the Murray-Darling Basin. But in this case, we can point to decreased rainfall from climate change as the reason the Murrumbidgee River catchment is losing water.
Under climate change, we can expect further drying of wetlands and major losses of wildlife habitat. For farmers and communities, we can expect huge reductions in the amount of water allocated for irrigation. The ability for communities to survive these severe decreases in agricultural productivity will be tested.
The Paraná River, one of the main commercial waterways in South America, has reached its lowest level in nearly 80 years due to a prolonged drought in Brazil that scientists attribute to climate change.
The Paraná waterway and its aquifers supply fresh water to some 40 million people in countries including Brazil and Argentina. In turn, it receives water from the Paraguay River, which has among its main sources the Pantanal area, a huge wetland located in the Mato Grosso region of southern Brazil.
The drought of the river is impacting the transport of goods. Vessels have had to reduce their tonnage by approximately 20% to continue moving. In 2019, 79 million tons of grain, flour and oil were exported from Rosario, according to the city’s stock exchange, making it one of the biggest agricultural export hubs in the world.
“In the past, we may have had one fire in the summer that was notable. Now 50% of our fires are notable—and what I mean by notable is something that really, really exceeded our expectations on growth and intensity.”