The population affected by floods and landslides in Brazil could double or even triple in the coming decades, in a scenario of global warming of 1.5ºC – currently, the planet has already warmed 1.1ºC compared to pre-industrial levels.
The conclusion is among the regional highlights of the new report of the UN climate panel, the IPCC (Intergovernmental Panel on Climate Change). Launched this Monday (28) by 270 authors, the work updates knowledge on the socioeconomic impacts of climate change, based on the review of 34,000 articles.
The rise in temperature already increases the frequency and intensity of heavy rains and floods, with the rapid formation of denser clouds. But climate projections point to expansion of the affected areas.
If global greenhouse gas emissions continue to rise, there will be a greater risk of more frequent and extreme floods in the states of Acre, Rondônia, southern Amazonas and Pará. In the Amazon delta, between Pará and Amapá, 41% of the population is exposed to flood damage.
The country is also among the most vulnerable to extreme heat waves, with regions of the country being able to reach increases of 2ºC to 6ºC in average temperature.
The sum of heat and humidity creates dangerous conditions and can be deadly, particularly for young and old.
Heat waves, lasting at least two days, lasted three days longer in Brazil between 2016 and 2020 compared to the period from 1986 to 2005.
“A wet bulb temperature [medida que combina calor e umidade] 35°C is unbearable for more than about six hours, even for healthy, fit adults resting in the shade,” the study says.
If emissions continue to rise, parts of the North, Northeast and Midwest of Brazil will be subject to these dangerous heat conditions for up to 30 days a year. In this scenario, deaths from heat in Brazil will increase by 3% by 2050 and 8% by 2090.
Urban heat islands are also likely to expose residents of large cities such as São Paulo and Rio de Janeiro.
The combination of increased heat and humidity also makes the climate more conducive to infectious diseases such as dengue, zika, chikungunya and malaria.
In some regions of the country, the potential for dengue transmission has increased from 17% in the 1950s to 80% in the last five years, an effect now attributed by science to climate change.
Floods also increase the occurrence of diarrheal diseases, leptospirosis and dermatitis. The warmer climate also facilitates the emergence of zoonoses transmitted by viruses. Across the country, there is a risk of severe epidemics caused by climate-sensitive vectors.
With changes in temperature, scientists have already observed the spread of diseases to areas that were previously unaffected. Projections on malaria confirm that the climatic factor influences the geographic reach, the intensity of transmission and the seasonality of the disease.
“Changes in the risk pattern become more complex with rising temperatures,” the report says.
Despite the increase in heavy rains, average annual rainfall in the country is expected to fall by 22% over the century, according to climate panel projections, if global greenhouse gas emissions continue to rise, that is, rains fall more concentrated and at less regular periods.
Meanwhile, the droughts are expected to last longer, affecting the Northeast, Midwest, Southeast and South regions. The change in the hydrological pattern puts the entire country at risk of food insecurity.
In the Amazon, the change from rainforest to dry pastures can reduce rainfall by 40%, breaking the distribution of rainfall to the South and Southeast.
In Northeast Brazil, droughts lasting at least one month reached an area 64.5% larger in the last decade compared to the 1950s. Areas with droughts longer than three months also expanded by 38% and those affected by more of six months increased by 12% over the same period.
The Northeast region is among the most sensitive on the continent to climate-forced migrations. Worldwide, droughts, floods, storms and hurricanes are among the most common climatic causes of displacement.
The impact of these extreme events is even greater on women. According to the report, in crisis situations generated by climate disasters, women lose work and turn to the informal economy more often than men.
Weather extremes also disproportionately affect people in poverty and extreme poverty, children, the elderly, people with disabilities and indigenous populations, who have already suffered climate impacts such as water scarcity, reduced agricultural production and displacement.
“In displacements and migrations forced by climatic effects, women are more likely to lose their leadership, autonomy and voice, especially in new organizational structures imposed by authorities. This is especially the case for temporary camps created after disasters, which increase inequalities. existing”, says the report in the chapter dedicated to the region of South and Central America.
Although the catastrophic impacts are already observed today, there are measures to adapt to climate change that can stop the trend of increasing climate impacts.
The climate panel cites examples of adaptation policies that have been effective.
Among the actions taken by the government, the report cites the creation of green spaces in urban areas, relocation of families located in disaster-prone areas, restoration and improvement of access to drinking water.
“Construction of green-gray infrastructure has been a popular public adaptation measure to reduce deaths and injuries due to floods. Infrastructure has been improved in schools, public buildings and drainage systems in cities such as Bogotá (Colombia) and La Paz, in Bolivia. In Brazil, canalization works were implemented to reduce the flooding of the Tietê River, which crosses the metropolitan region of São Paulo, based on flood simulations”, exemplifies the study.
“Another example of a public adaptation measure is the protection and restoration of natural areas, which has the potential to reduce the transmission of infectious diseases transmitted by water and vectors”, says the climate panel.
