The number of heatwave days has increased by 642% in 30 years in Brazil, according to a study

Frequently in the news in 2023, heat wave records have increased by 642% over the last 30 years in the country, according to a study by the National Institute for Space Research (Inpe) which seeks to understand the evolution of the country’s climate. changing.

Carried out at the request of the Ministry of Science, Technology and Innovation (MCTI), the survey addresses trends in rain, heat and humidity episodes. The calculations were carried out for the entire Brazilian territory and consider the period from 1961 to 2020.

The researchers established the years 1961 to 1990 as the reference period and carried out segmented analyzes of climate change over three periods: 1991-2000, 2001-2010 and 2011-2020.

The data indicate that there was a progressive increase in heatwave episodes throughout the periods analyzed in practically all of Brazil.

During the reference period, the number of days with temperatures above normal did not exceed seven. Between 1991 and 2000, this value increased to 20 days. For the period 2001-2010, it reached 40 days; and from 2011 to 2020, the number of heatwave days reached 52 days.

A heatwave is characterized by a minimum of 6 consecutive days during which the maximum temperature has exceeded a threshold of at least 10% of what is considered extreme, compared to the reference period.

Between 1991 and 2000, maximum temperatures above average did not exceed 1.5°C. However, they reached 3°C in places for the period 2011 to 2020, particularly in the North-East region.

During the reference period, the average maximum temperature in the Northeast was 30.7°C and gradually increased to 31.2°C between 1991 and 2000, 31.6°C between 2001 and 2010 and 32.2°C between 2011 and 2020.

“This information is the source that we can consider reliable for what is felt in the daily life of society. These are relevant data for climate science to support decision-making,” said MCTI Department for Climate and Sustainability Director Osvaldo Moraes.

The study also indicates that there was an inverse variation in accumulated precipitation in the Northeast and South regions between 2011 and 2020.

While there was a decrease in the average rate of precipitation, with variations between –10% and –40% from the northeast to the southeast and in the central region of Brazil, an increase was noted between 10% and 30% in the area covering the Southern region states and part of the states of São Paulo and Mato Grosso do Sul.

Another insight from the research is the finding that the southern region has been most affected by extreme rainfall in recent decades. During the reporting period, the maximum five-day rainfall was around 140 mm, a figure which rose to an average of 160 mm.

According to the researchers’ conclusion, the climate is already changing and affecting the country in multiple ways. While in some regions there is an increase in temperature, in others there is an increase in precipitation or droughts.

“The most recent IPCC report highlighted that climate change impacts different regions of the world differently. Our analyzes clearly reveal that Brazil is already experiencing these transformations, as evidenced by the increase in the frequency and intensity of extreme weather events in several regions since 1961 and which will worsen in the decades to come in proportion to global warming. », Explains Lincoln Alves, researcher at Inpe. who coordinated the studies.