Global warming is causing an intensification of extreme climate events with significant changes in frequency, duration, and intensity over many regions. Understanding the current and future influence of this warming in northeastern Brazil (NEB) is important due to the region’s greater vulnerability to natural disasters, as historical records show. In this paper, characteristics of climate change projections (precipitation and air temperature) over NEB are analyzed using 15 models of Coupled Model Intercomparison Project Phase 6 (CMIP6) under four Shared Socioeconomic Pathways (SSPs: SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) scenarios. By using the Taylor diagram, we observed that the HadGEM3-GC31-MM model simulates the seasonal behavior of climate variables more efficiently. Projections for NEB indicate an irreversible increase in average air temperature of at least 1 °C throughout the 21st century, with a reduction of up to 30% in annual rainfall, as present in scenarios of regional rivalry (SSP3-7.0) and high emissions (SSP5-8.5). This means that a higher concentration of greenhouse gases (GHG) will increase air temperature, evaporation, and evapotranspiration, reducing rainfall and increasing drought events. The results obtained in this work are essential for the elaboration of effective strategies for adapting to and mitigating climate change for the NEB.

Knowing the dynamics of spatial–temporal precipitation distribution is of vital significance for the management of water resources, in highlight, in the northeast region of Brazil (NEB). Several models of large-scale precipitation variability are based on the normal distribution, not taking into consideration the excess of null observations that are prevalent in the daily or even monthly precipitation information of the region under study. This research proposes a novel way of modeling the trend component by using an inflated gamma distribution of zeros. The residuals of this regression are generally space–time dependent and have been modeled by a space–time covariance function. The findings show that the new techniques have provided reliable and precise precipitation estimates, exceeding the techniques used previously. The modeling provided estimates of precipitation in nonsampled locations and unobserved periods, thus serving as a tool to assist the government in improving water management, anticipating society’s needs and preventing water crises.

RESUMO Devido à rápida expansão urbana e potencial turístico da região, o objetivo deste estudo foi a obtenção da distribuição temporal dos índices de extremos climáticos dependentes de dados diários de temperatura e precipitação, definido pela OMM, para o período de 1975 a 2011, e utilizando os testes estatísticos não paramétricos obter a magnitude das tendências dos referidos índices para a cidade de Campina Grande - PB. Os resultados mostram que as temperaturas mínimas e máxima diárias têm aumentado gradativamente ao longo das últimas décadas, apresentando tendências sazonais crescentes ao longo dos anos e que as temperaturas mínimas tiveram maior aumento. O número de dias e noites quentes por ano tem aumentado, proporcionando assim uma redução significativa dos dias e noites frias. Foi observado que as temperaturas mínimas e máximas apresentam maiores tendências de aumento nas estações do outono e primavera, respectivamente. Baseado nos índices extremos de precipitação, mesmo sem significância estatística, foi observado que as chuvas intensas tendem a aumentar, ocorrendo em um período menor de tempo.

Trends in extreme climate indices were obtained with ERA40 gridded precipitation data over northern Brazil region that includes most of the Amazon Basin and interior of Northeast Brazil. The indices representing one-day highest precipitation in a month, number of rainy days, monthly maximum 5-day consecutive precipitation and number of heavy precipitation days showed increasing trends over most of the grid points of the study region. Although negative trends in wet days were obtained at some grid points, they are not statistically significant. The negative trends are mostly confined to Mato Grosso and southern Pará states, where the deforestation in the period of study was intense. Consistently, the index representing the number of dry days showed a negative trend at the points where the number of wet days, very wet days and annual precipitation amounts showed positive trends.Keywords: Amazon, deforestation, sea surface temperature, reanalysis Tendências nos Extremos de Precipitação sobre a Parte Norte do Brasil através dos Dados do ERA40 RESUMO Foram obtidas tendências em índices de extremos climáticos com dados de precipitação do ERA40 para a parte norte do Brasil que inclui grande parte da Bacia Amazônica e do Nordeste do Brasil. Os índices que representam os maiores valores de precipitação em um dia, número de dias chuvosos, precipitação máxima em 5 dias consecutivos e o número de dias anuais com precipitação intensa mostraram tendências crescentes para a maioria dos pontos de grade da região de estudo. Embora tenham sido encontradas tendências negativas para os dias úmidos em alguns pontos de grade, os mesmos não apresentaram significância estatística. As tendências negativas são principalmente limitadas para Mato Grosso e sul do Pará onde o desmatamento no período de estudo foi intenso. Constantemente, o índice que representa o número de dias secos mostrou uma tendência negativa para os pontos onde o número de dias úmidos, muito úmidos e a precipitação total anual mostraram tendências positivas. Palavras - chave: Amazônia, desflorestamento, temperatura da superfície do mar, reanálises

Extreme weather events, such as heat waves, heavy rainfall and droughts, have become more frequent and intense in Brazil. According to climate change scenarios, this trend, which has a negative impact on people’s health and living conditions, will continue. Here, we analysed indicators for extreme weather events resulting from climate change, projected for the 21st century, alongside socio-demographic indicators for Brazilian municipalities, in an attempt to identify populations exposed to the risks of the climate crisis. We calculated the values of indicators for extreme air temperature and precipitation events, based on NEX-GDDP-CMIP6 data, for a reference period and for the future, as well as socio-demographic indicators based on recent census data. Using Spearman’s coefficient, we then calculated anomaly indicators for the future time intervals and analysed correlations with the socio-demographic indicators. Our results indicate a reduction in cold days and an increase in hot days and heat waves in both scenarios (SSP2-4.5 and SSP5-8.5), with the most changes occurring in the highest emission scenario. The extreme precipitation indicators suggest both an increase and a reduction in intense precipitation and droughts in a number of the country’s regions. The projected changes are more intense in the highest emission scenario, and in the North and Northeast regions. We noted a trend for greatest occurrence of extreme events in locations with a higher proportion of Black, Parda/Brown, Indigenous and Quilombola populations, and the socially vulnerable. We recommend that policies to adapt and mitigate the impacts of climate change focus on reducing inequalities and promoting climate justice.

Working under extreme heat conditions threatens health and well-being, which is aggravated by climate change. This study estimated the impact of an increase in global temperature on workability in the Brazilian population and its respective economic costs, under two climate change scenarios, projected over the 21st century. Using daytime Wet Bulb Globe Temperature (WBGT) projections from Coupled Model Intercomparison Project (CMIP6) climate models (SSP2-4.5 and SSP5-8.5 scenarios), we estimated productivity losses in the country’s principal labour activities: agriculture, civil construction, the manufacturing industry, services, and informal labour. The economic cost was obtained from daily wages, number of workers and productivity loss. Our results indicate that the North, Northeast and Central-West regions face significant increases in daytime WBGT, frequently surpassing 34 °C in the SSP5-8.5 scenario, which may exacerbate the effects of outdoor activities as they are currently carried out. In agriculture and civil construction, productivity could fall by 90%. Daily economic losses for regulated labour activities could reach USD 228 million under SSP2-4.5 and up to USD 353 million in SSP5-8.5. To reduce these impacts, global mitigation action to curb the increase of global temperature must be implemented, while national public policies that protect workers, such as creating cool spaces, providing regular breaks, adjusting working hours and encouraging hydration, must be adopted and reinforced.