Brazil has been hit by a series of devastating floods and landslides in the past few months, leaving hundreds of people dead or missing and thousands more displaced.
The latest disaster occurred in the southern state of São Paulo, where torrential rains triggered mudslides that buried homes and roads, killing at least 48 people and leaving 38 more unaccounted for.
The governor of São Paulo, Tarcísio de Freitas, declared a state of emergency and said it was the worst weather disaster in the state's history.
But what are the causes and consequences of these extreme weather events? Are they a result of climate change or human negligence? And how can Brazil cope with the challenges of disaster prevention and recovery?
The impact of climate change on Brazil's rainfall patterns
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Brazil is a country of contrasts, with diverse climates and ecosystems. It is home to the world's largest rainforest, the Amazon, which covers about 60% of its territory and produces about 20% of the world's oxygen.
It also has vast areas of savanna, known as the Cerrado, and semi-arid regions, such as the Caatinga.
The country's rainfall patterns are influenced by several factors, such as the El Niño and La Niña phenomena, which affect the temperature and circulation of the Pacific Ocean, and the Atlantic Multidecadal Oscillation, which affects the salinity and temperature of the Atlantic Ocean.
However, climate change is also affecting Brazil's weather, causing more frequent and intense droughts and floods.
According to a study by the Brazilian Institute of Geography and Statistics (IBGE), the average annual rainfall in Brazil decreased by 6.4% between 1961 and 2018, while the number of days with heavy rainfall increased by 64.9%.
The study also found that the south-east and southern regions of Brazil, which include the states of São Paulo, Rio de Janeiro, Minas Gerais, Paraná, Santa Catarina, and Rio Grande do Sul, were the most affected by the changes in rainfall patterns, with a reduction of 15.6% and 13.3% in average annual rainfall, respectively.
These changes have serious implications for Brazil's water security, agriculture, energy, biodiversity, and human health.
For instance, the southeast region, which accounts for about 40% of Brazil's population and gross domestic product (GDP), faced a severe water crisis in 2014 and 2015, when the main reservoirs that supply water to millions of people reached critically low levels.
The drought also affected the production of hydroelectric power, which represents about 65% of Brazil's electricity generation.
On the other hand, the southern region, which is the main producer of grains, such as soybean and corn, and livestock, such as cattle and pigs, suffered from floods and hailstorms that damaged crops and infrastructure in 2015 and 2016.
The floods also increased the risk of waterborne diseases, such as leptospirosis and dengue fever, and vector-borne diseases, such as malaria and yellow fever.
The role of human activities in exacerbating Brazil's vulnerability to disasters
While climate change is a global phenomenon that affects all countries, Brazil's vulnerability to disasters is also influenced by human activities, such as deforestation, urbanization, land use, and environmental degradation.
According to the World Bank, Brazil ranks among the top 10 countries in the world with the highest economic losses due to natural disasters, with an average annual loss of US$ 2.8 billion between 1995 and 2014.
However, the World Bank also estimates that about 70% of these losses could be avoided or reduced by investing in disaster risk management and resilience.
One of the main factors that increase Brazil's exposure and susceptibility to disasters is deforestation, especially in the Amazon region.
The Amazon rainforest plays a crucial role in regulating the climate and the water cycle, not only in Brazil but also in other parts of South America and beyond.
The forest acts as a giant sponge, absorbing and releasing water through evaporation and transpiration, creating what is known as the "flying rivers", which are streams of moist air that travel across the continent and bring rainfall to other regions.
However, deforestation reduces the forest's capacity to store and release water, affecting the quantity and quality of rainfall and increasing the risk of droughts and floods.
According to the National Institute for Space Research (INPE), Brazil lost about 11,000 square kilometers of forest cover in the Amazon in 2020, the highest rate since 2008.
Another factor that contributes to Brazil's vulnerability to disasters is urbanization, especially in the coastal areas and the metropolitan regions of São Paulo and Rio de Janeiro.
According to the IBGE, about 86% of Brazil's population lives in urban areas, and about 25% lives in informal settlements, such as slums and shantytowns.
These settlements are often located in precarious and hazardous areas, such as hillsides, riverbanks, and floodplains, where the residents have limited access to basic services, such as water, sanitation, drainage, waste management, and public transportation.
These conditions increase the exposure and sensitivity of the urban poor to disasters, such as landslides and floods, as well as to social and economic shocks, such as unemployment, violence, and crime.
A third factor that affects Brazil's resilience to disasters is land use and environmental degradation, especially in the rural areas and the agricultural frontier.
Brazil is one of the world's largest producers and exporters of agricultural commodities, such as soybean, sugar, coffee, beef, and poultry.
However, the expansion of agriculture and livestock has often been associated with the conversion of natural habitats, such as forests, wetlands, and grasslands, into monocultures, pastures, and plantations.
This process reduces the biodiversity and the ecosystem services that these habitats provide, such as soil conservation, water regulation, carbon sequestration, and pollination.
It also increases the vulnerability of the rural population and the agricultural sector to climate variability and extremes, such as droughts, floods, pests, and diseases.
