Brazilian coast has warmed significantly and experiences many extreme temperature events

Climate change is striking with a vengeance along the Brazilian coastline, particularly in the South and Southeast regions, resulting in extreme temperature events.

The escalating severity of surface air temperatures and erratic switches from blistering heat to chilling cold are tangible evidence of this shift, as detailed in a recent study published in the journal Scientific Reports.

A marked upswing in temperature extremes and heatwaves (defined as multiple consecutive days of intense heat) over the past 40 years is distinctly evident along the coasts of Espírito Santo, Rio Grande do Sul, and São Paulo states. The uptick in these meteorological occurrences has skyrocketed by 188%, 100%, and 84% respectively across these states.

The coastal region of Espírito Santo has weathered temperature extremes, with the highest temperature soaring to 37.2°C in March 2013 from a more comfortable 28.6°C in July 1987. Meanwhile, the coldest temperature dipped from 20.7°C in January 2016, a stark contrast to the more moderate 11.2°C in June 1993.

Moreover, temperatures surpassing a scorching 35°C were recorded eight times in Espírito Santo until 1999, but that number has more than doubled to 19 times in the past decade. The coastline of Rio Grande do Sul exhibits a unique trend; the daytime temperatures are showing a warming trend as the lower limits are less severe.

How scientists studied the extreme temperature events

Scientists from the Institute of Marine Sciences at the Federal University of São Paulo (IMAR-UNIFESP) conducted this comprehensive study, analyzing temperature extremes of various intensities and frequencies along the Brazilian coast.

“The dataset and method used here seem to be a reliable approach for studies of climate extremes, with clear indicators of intensity, frequency, and duration,” the scientists noted in their conclusions. The methodology used could also be implemented in studying other regions of the globe, they add.

“The Southeast and South are already experiencing temperatures that could affect both biodiversity and the economy. The coast of Espírito Santo was the most affected out of the five regions analyzed because it was the only one where the frequency of both extreme cold events and heatwaves increased,” said Fábio Henrique Carretero Sanches, the study’s lead author, who received postdoctoral scholarship support from FAPESP.

Impact of extreme temperatures on biodiversity

The impact on biodiversity is profound. With extreme temperatures comes physiological alterations and behavioral changes in various species, leading to increased mortality rates among both terrestrial and aquatic animals.

For Ronaldo Christofoletti, a fellow researcher at IMAR-UNIFESP and the article’s final author, these findings hold significant implications for public health.

“Extremes of heat and cold affect society in several ways, from thermal discomfort to forest fires, diseases, and deaths among animals, plants, and humans, especially older people and people in situations of vulnerability,” he warned. Christofoletti’s research was also supported by FAPESP.

The broader implications of these findings are alarming. According to a UNICEF report, heatwaves currently expose around 559 million children globally. If the global average temperature climbs by 1.7°C compared with pre-industrial times, this number could swell to an astronomical 1.6 billion by 2050.

Furthermore, heatwaves were responsible for at least 15,000 deaths in Europe just last year, with Spain and Germany being hit hardest, according to the World Health Organization (WHO).

“The changes in patterns of extreme weather on the coast are an important warning sign of Brazil’s overall climate vulnerability. Our study confirmed that the climate emergency isn’t futurology but part of a reality we have to deal with by combating its causes with concrete actions to mitigate its impacts and effective public policies for adaptation,” said Ana Toni, national secretary for climate change at the Brazilian Ministry of the Environment and Climate Change, in a statement relayed through her press office.

A report from the Intergovernmental Panel on Climate Change (IPCC) issued in March affirmed that human activities have categorically escalated greenhouse gas emissions to unprecedented levels.

Humans are quickly driving global temperatures 1.5 °C above pre-industrial levels before 2030. This warming leads to worldwide alterations, including rising sea levels and severe weather, causing extensive harm to life, livelihoods, and natural ecosystems.

Study used 40 years of hourly data

This extensive research utilized mathematical models and data spanning four decades of hourly surface air temperatures, recorded daily across five coastal areas – São Luís (Maranhão), Natal (Rio Grande do Norte), São Mateus (Espírito Santo), Iguape (São Paulo), and Rio Grande (Rio Grande do Sul).

The scientists took into account regional and seasonal differences when defining extreme temperatures for each area and month. Notably, no changes in patterns of temperature extremes were discovered for São Luís and Natal (both in Northeast Brazil) throughout the year.

“Climate change studies require historical data and continuous monitoring data. To understand the current pattern of extreme events and project future scenarios that contribute to coastal resilience plans, we must urgently increase the number of weather stations on the Brazilian coast,” Sanches emphasized.

This call to action underscores the urgency and scale of the climate crisis we’re currently grappling with and the importance of continuously monitoring and understanding this global issue.

More about extreme temperature events

Extreme temperature events refer to periods of exceptionally hot or cold weather. They are becoming more frequent and severe due to climate change and pose significant risks to human health, agriculture, and ecosystems.

Here is everything you need to know about these events:

Definition

An extreme temperature event, depending on the context, can refer to an unusually hot or cold period relative to the local climate and time of year. It includes heatwaves (extremely hot weather over a period), cold snaps (sudden drops in temperature), and instances of unseasonal warmth or chill.

Causes

Extreme temperature events can be caused by various factors, including atmospheric pressure systems, ocean currents, and broader climatic patterns. They can also be influenced by local factors such as topography and urban heat islands. Human-driven climate change is making these events more frequent and intense.

Impact on human health

Heatwaves can cause heat exhaustion, heatstroke, and exacerbate existing health conditions, particularly in vulnerable populations, like older people and those with chronic illnesses. Cold snaps can lead to hypothermia and frostbite, and also worsen existing conditions such as cardiovascular and respiratory diseases.

Environmental impacts

Extreme heat can lead to drought, wildfires, and heat stress in plants and animals, while extreme cold can cause freeze-thaw damage to plants and stress to wildlife not adapted for such conditions. These events can significantly disrupt ecosystems and lead to loss of biodiversity.

Economic impact

Extreme temperature events can lead to economic losses due to factors such as crop failure, reduced labor productivity, increased energy demand, and health costs. They can also damage infrastructure, from roads buckling in heat to pipes freezing in cold.

Mitigation and adaptation

Communities can mitigate the impact of extreme temperature events through early warning systems, public health interventions, infrastructure adaptation, and community preparedness. Climate change mitigation, to prevent further increases in extreme temperature events, is also crucial.

Climate change and extreme temperature events

Climate change is making extreme temperature events more common and severe. Rising global temperatures increase the frequency and intensity of heatwaves, while changes in atmospheric circulation patterns can lead to more frequent and intense cold snaps in certain regions.

Historical events

There have been many notable extreme temperature events throughout history. For instance, the European heatwave of 2003 caused over 70,000 deaths. The 2010 heatwave in Russia led to widespread wildfires and approximately 50,000 deaths. The US “Polar Vortex” of 2019 saw temperatures drop as low as -40°F (-40°C) in the Midwest.

Future projections

According to the Intergovernmental Panel on Climate Change (IPCC), extreme temperature events will become more frequent and severe in the future due to ongoing global warming. This will increase the risk to human health, agriculture, and ecosystems, and make adaptation efforts increasingly important.

In summary, extreme temperature events are a major aspect of climate change and pose significant challenges for society and ecosystems. Monitoring, understanding, and preparing for these events is crucial for human health and the environment.