Experts are divided over the extent of an overheating planet’s role in the South American country’s chronic dry spell
By Fabiola Ortiz in Sao Paulo
Brazil’s worst drought in 80 years has seen water rationing and the threat of army intervention to cope with growing social unrest.
Sao Paulo, a parched metropolis of 20 million, has become the poster child of a water crisis affecting one in six of the country’s cities.
Scarce rainfall has had the broadest impact in Brazil’s north east, with 90% of the 936 municipalities declaring “disaster situations”.
But it’s the country’s south east, the economic powerhouse containing Sao Paulo and Rio de Janeiro and key producer of agricultural exports like soybeans and sugar, where the damage is most intense.
Deforestation in the Amazon basin and climate change are held as culprits, but so too are lacklustre urban planning and wasteful water consumption.
A top official at Brazil’s environment ministry, Sergio Henrique Collaco said that decades of logging and global warming are reducing rains and “changing the dynamics of the Amazon rainforest”.
Forests have the dual advantage of sucking up carbon and pumping moisture through the canopy in a process known as evapotranspiration. Dubbed “flying rivers“, that raises air pressure and triggers precipitation around the country.
Years of unchecked deforestation have scaled back that capacity, according to the Brazilian National Space Research Institute.
Rising atmospheric concentrations of carbon dioxide and deforestation have aggravated the situation, said Ney Maranhao, water resources and urban environment secretary at the environment ministry.
But current trends could be a “natural fluctuation” and not necessarily the work of climate change, Maranhao told RTCC in an interview.
“We need more time to observe. Maybe only by 2040 climate change will be really perceptible.”
— Assaad Razzouk (@AssaadRazzouk) May 10, 2015
Brazil could enter a critical phase if rains don’t return to historic averages by October, he added, replenishing reservoirs that provide hydroelectricity generation, irrigation for farms, and drinking water.
Despite recent rains, the Cantareira reservoir which supplies over 5 million people holds just 20% of its capacity. Last year as the city braved another bout of dryness, that level was just 10%.
Rains in May have been just 40% of the normal rate, with forecasts not predicting any more for another fortnight.
And almost a quarter of Brazil’s 200 million citizens are living in areas with reservoirs and precipitation below historical averages, Rio de Janeiro-based newspaper O Globo reported.
But Sao Paolo’s worse have been compounded by a lack of planning and poor conservation of water.
The average Brazilian citizen uses 185 litres per day, way above the World Health Organization’s guideline of 100. The high proportion of water used in treating sewage in the mega-city drains resources.
— iG (@iG) May 11, 2015
According to the UN Special Rapporteur on human rights to water and sanitation Leo Heller, the ongoing water crisis arose from lax planning that didn’t consider “seasonal climate changes or foresee measures that mitigate the situation in securing water access for the population”.
Maranhao, the official, believes Brazil has a 25-year window until it sees the worst of climate impacts.
Indeed a temperature rise of 2.5C would erase 3% of Latin America and the Caribbean’s gross domestic product by 2050, according to a UN regional economic commission.
All this comes as Brazil prepares its carbon cutting pledge to a UN climate deal.
Near Vargem, Brazil: A man shows me how low the water is under this bridge. “Never seen anything like it,” he said. pic.twitter.com/GOfilVzsww
— Gabriel Elizondo (@elizondogabriel) October 17, 2014
Experts close to the country’s policymakers told RTCC earlier this month there was a lack of urgency at the highest levels to volunteer its target, despite the drought crisis.
Though the government has said it will invest $500 million to build pipelines and connect parched reservoirs to fuller ones, Maranhao said.
“Cities will need to improve their drainage system, collect and stock water for longer periods. All will go through a revaluation process,” the official says.
“Getting out of a crisis like this one takes time.”