Teoria racial crítica e a melhoria da performance acadêmica de ativistas

Teoria racial crítica desperta ativismo nos alunos, por Jerusha Osberg Conner (Professora de Educação, Universidade Villanova), 21/06/2021

 A teoria crítica da raça - uma estrutura acadêmica que sustenta que o racismo está embutido na sociedade - se tornou o assunto de um intenso debate sobre como as questões de raça devem ou não ser ensinadas nas escolas.

O que falta no debate é a evidência de como a exposição à teoria crítica da raça realmente afeta os alunos.

Como pesquisadora especializada em ativismo juvenil, conduzi pesquisas sobre e com grupos organizadores de jovens nos quais a teoria racial crítica é um componente central da educação política. Oitenta e dois por cento dos grupos organizadores de jovens oferecem regularmente educação política, que envolve um exame crítico das questões sociais, geralmente por meio de workshops e discussões em grupo.

Minha pesquisa - junto com a de outros acadêmicos - aponta para três resultados importantes para os jovens que aprendem a teoria racial crítica como parte da organização juvenil.

1. Acende paixão
Uma garotinha negra em uma rua segura uma placa que diz 'Poder para meu povo !!'

O estudo da teoria racial crítica ajuda as pessoas a entender como a opressão sistêmica pode impactar a vida diária.

Em primeiro lugar, a pesquisa mostra que aprender a aplicar uma perspectiva teórica racial crítica e pensar criticamente sobre a sociedade não alimenta um sentimento de divisão entre os jovens, como alguns políticos sugeriram.

Em vez disso, descobri que fazer isso pode despertar nos jovens a paixão por trabalhar de forma colaborativa para gerar mudanças sociais voltadas para a equidade.

Em minha pesquisa, observei que, quando os organizadores da juventude aprendem como o poder e o privilégio são reproduzidos de uma geração para a outra por meio de políticas racializadas, como "redlining" (ou discriminação na habitação), financiando distritos escolares com base em impostos sobre a propriedade, o que favorece distritos escolares mais ricos, e acompanhando os alunos em diferentes níveis acadêmicos, eles frequentemente se inspiram a tomar medidas para corrigir as condições injustas.

Muitos dos jovens organizadores de baixa renda negros que estudei perceberam que a maioria de suas dificuldades na vida não é culpa deles. Eles desenvolvem a esperança de que a reforma seja possível apenas se os formuladores de políticas e o público adotarem políticas mais equitativas. E então eles começaram a trabalhar elaborando e defendendo tais políticas.

Em um grupo de organização de jovens, meus colegas e eu estudamos, os alunos ensinam uns aos outros um modelo chamado “a espiral da opressão”.

Essa estrutura ajuda os jovens a compreender como a opressão social de grupos de pessoas, como minorias raciais ocorrem em uma espiral, na medida que os indivíduos desses grupos internalizam a opressão e começam a agir de acordo com os estereótipos negativos que internalizaram. Essas ações, por sua vez, levam a mais opressão, como:
 maior vigilância policial,
supervisão e violência estatal.
Nesse sentido, a espiral continua.

Ao longo dos anos, os participantes me disseram repetidamente como foi empoderador aprender essa estrutura de "espiral da opressão". Isso os ajudou a entender o que viram acontecer em suas comunidades. Mais significativamente, isso os levou a considerar como poderiam interromper a espiral, tanto individual quanto coletivamente. Em vez de se verem através das lentes binárias de vítima ou opressor, eles adotaram identidades como agentes de mudança, comprometidos com a reforma institucional e social.

2. Melhora acadêmica

Em segundo lugar, a pesquisa mostra que os organizadores de jovens se tornam mais bem-sucedidos academicamente na escola à medida que progridem na organização.

Por exemplo, em um estudo, descobri que dois terços dos organizadores de jovens ativamente envolvidos nas escolas de pior desempenho da Filadélfia melhoraram significativamente suas médias de notas.

Da mesma forma, outros acadêmicos descobriram que os organizadores da juventude são mais propensos do que seus colegas a relatar que receberam principalmente notas A e B no ensino médio, e passam a frequentar faculdades de quatro anos com taxas mais altas. Ironicamente, a pesquisa mostra que, embora a organização de jovens ajude-os a se tornarem mais conscientes das desigualdades dentro e entre as escolas, também pode torná-los menos alienados na escola e mais comprometidos com os estudos.

3. Benefícios ao longo da vida

Terceiro, os benefícios de ser exposto à teoria racial crítica por meio da organização dos jovens não terminam no ensino médio ou na faculdade. Minha pesquisa mostrou que as experiências formativas na organização de jovens podem moldar as escolhas que os indivíduos fazem em sua vida profissional e cívica quando adultos.

Os ex-alunos explicam como os valores e as disposições cultivadas na organização os levaram não apenas a adotar carreiras pró-sociais como, por exemplo, educadores ou conselheiros, mas também a encontrar maneiras de continuar a participar de forma construtiva na vida cívica de suas comunidades como jovens adultos.

Outros pesquisadores encontraram resultados semelhantes. Em um estudo em grande escala na Califórnia, os pesquisadores descobriram que, como adultos, os ex-organizadores da juventude têm muito mais probabilidade do que seus colegas de se apresentarem como voluntários, trabalharem em uma questão que afeta sua comunidade, participarem de organizações cívicas e se registrarem para votar. Esses resultados levantam a questão: esses resultados poderiam se tornar mais generalizados se as escolas adotassem alguns dos princípios e estruturas curriculares da organização juvenil, incluindo a teoria racial crítica?

À medida que o debate sobre a teoria racial crítica e seu lugar nas escolas continua, é importante que o discurso seja fundamentado em evidências.

Estudos de organização de jovens mostram que, quando bem ensinadas, as ferramentas analíticas da teoria racial crítica podem apoiar resultados educacionais, profissionais, cívicos e políticos valiosos a longo prazo.

Esses resultados são mais pronunciados para jovens negros de baixa renda. Quando os políticos promovem a legislação para bloquear o uso da teoria racial crítica nas escolas, eles podem na verdade estar bloqueando um meio importante de promover resultados que tornariam a democracia da América mais robusta e vibrante do que seria de outra forma.

Tradução: VanRes, Doutor em Letras (UFMG), Mestre em Letras (UFSJ). Professor de ensino médio na rede pública estadual de Minas Gerais.

 https://theconversation.com/critical-race-theory-sparks-activism-in-students-162649

Critical race theory sparks activism in students, by Jerusha Osberg Conner (Professor of Education, Villanova University)

June 21, 2021 3.13pm EDT

 

Critical race theory – an academic framework that holds that racism is embedded in society – has become the subject of an intense debate about how issues of race should or shouldn’t be taught in schools.

Largely missing in the debate is evidence of how exposure to critical race theory actually affects students.

As a researcher who specializes in youth activism, I have conducted research on and with youth organizing groups in which critical race theory is a core component of the political education. Eighty-two percent of youth organizing groups regularly offer political education, which involves a critical examination of social issues, usually through workshops and group discussions.

My research – along with that of other scholars – points to three important outcomes for young people who are taught critical race theory as part of youth organizing.

1. Ignites passion

Studying critical race theory helps people understand how systemic oppression can impact daily life. Angela Weiss/AFP via Getty Images

First, research shows that learning to apply a critical race theoretical perspective and think critically about society do not fuel a sense of divisiveness among youth, as some politicians have suggested.

Instead, I have found that doing so can ignite passion in youths to work collaboratively to bring about social change aimed at equity.

In my research, I have observed that when youth organizers learn how power and privilege are reproduced from one generation to the next through racialized policies like redlining or discrimination in housing, funding school districts on the basis of property taxes, which favors wealthier school districts, and tracking students into different academic levels, they often become inspired to take action to redress unfair conditions.

Many of the low-income youth organizers of color I have studied come to realize that most of their struggles in life are not their fault. They develop hope that reform is possible, if only policymakers and the public embrace more equitable policies. And so they set to work devising and advocating for such policies.

In one youth organizing group colleagues and I have studied, students teach one another a model called “the spiral of oppression.”

This framework helps young people understand how societal oppression of groups of people, such as racial minorities, spirals as individuals from those groups internalize oppression and begin to act on the negative stereotypes they have internalized. These actions, in turn, lead to further oppression, such as greater police surveillance, supervision and state violence as the spiral continues.

Across years, participants repeatedly told me how empowering it was to learn this framework. It helped them to make sense of what they saw happening in their communities. More significantly, it prompted them to consider how they could disrupt the spiral, both individually and collectively. Rather than seeing themselves through the binary lens of victim or oppressor, they adopted identities as change agents, committed to institutional and societal reform.

2. Improves academics

Second, research shows youth organizers become more academically successful in school as they progress through organizing.

For example, in one study, I found that two-thirds of the actively involved youth organizers in Philadelphia’s lowest-performing schools significantly improved their grade-point averages.

Similarly, other scholars have found that youth organizers are more likely than their peers to report that they received mostly A and B grades in high school, and they go on to attend four-year colleges at higher rates. Ironically, research shows that while youth organizing helps young people become more aware of inequities within and across schools, it can also make them less alienated in school and more committed to academics.

3. Lifelong benefits

Third, the benefits of being exposed to critical theory through youth organizing do not end in high school or college. My research has shown that formative experiences in youth organizing can shape the choices individuals make in their professional and civic lives as adults.

Alumni explain how the values and dispositions cultivated in organizing led them not only to adopt pro-social careers as, for example, educators or counselors, but also to find ways to continue to participate constructively in the civic life of their communities as young adults.

Other researchers have turned up similar results. In one large-scale study in California, researchers found that as adults, former youth organizers are far more likely than their peers to have volunteered, worked on an issue affecting their community, participated in civic organizations and registered to vote. These results raise the question: Could such outcomes become more widespread if schools adopted some of the principles and curricular frameworks of youth organizing, including critical race theory?

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As the debate over critical race theory and its place in schools rages on, it is important that the discourse be grounded in evidence.

Studies of youth organizing show that when taught well, the analytical tools of critical race theory can support valuable long-term educational, professional, civic and political outcomes.

These outcomes are most pronounced for low-income youth of color. When politicians advance legislation to block the use of critical race theory in schools, they may actually be blocking an important means of fostering outcomes that would make America’s democracy more robust and vibrant than it would otherwise be.

Que tal escrever uma "Carta para Esperança"?

Uma carta que " seja destinada a uma mulher negra que lhe deu esperança e, portanto, possa dar esperança a outras mulheres negras."

Se você é ou conhece "Mulheres negras/pretas, a partir de 15 anos que escrevam na língua portuguesa", não deixe de participar ou informá-las sobre o concurso "Carta para Esperança".

O prazo das INSCRIÇÕES: "de 8/06/2021 até 08/07/2021 ou até atingirmos 1.000 INSCRIÇÕES".

Serão selecionadas: "50 cartas para o 23º livro da Flup, a ser publicado em 2022".

Antes de enviar, revise sua carta utilizando o aplicativo CIRA. Mais informações em: https://vanresnews.blogspot.com/2021/06/cira-corretor-automatico-de-redacoes.html

Após revisar, envie sua carta (ATÉ 3.500 CARACTERES) utilizando o Formulário Google da FLUP. 

https://docs.google.com/forms/d/1ES6HEqJq4yBDJ3R7IcvX1C2Nc3W7aPlKCkeYp4pgBEo/viewform?edit_requested=true

Rapidez e alto desempenho, cui bono?

"Deve-se compreender a velocidade em sua dimensão política, juntamente com a técnica. Para que e para quem a rapidez ou a lentidão? Onde elas têm lugar? Na construção de um modelo cívico, importará mais o tempo das necessidades da população e dos lugares do que o tempo mais expresso, produtor de alienação."

https://outraspalavras.net/crise-brasileira/correios-como-a-privatizacao-fere-o-brasil/

June 18, 2021

Anti-Critical Race Theory and Neo-McCarthyism, by Timothy Messer-Kruse

Photograph Source: Screenshot/Fox News

On June 15, the “Promoting Education Not Indoctrination Act” was introduced in the Ohio legislature by Sarah Fowler Arthur, a first-term representative from the overwhelmingly white district of northeastern Ohio that includes both the rustbelt lake towns of Ashtabula and Conneaut and the Cleveland suburb of Chardon. Like many other bills now making their way to law in red states across America, H.B. 327 would outlaw the teaching of what its proponents label as “critical race theory” which they define as the idea that the “United States is fundamentally racist or sexist” or that anyone “is inherently racist, sexist, or oppressive, whether consciously or unconsciously.” Unlike similar measures in other G.O.P. controlled states, H.B. 327 very specifically applies its prohibitions to Ohio’s large public university system, threatening any institution that allows such teaching with a reduction of one quarter of its state funding.

In her press conference soon after successfully pushing the bill through committee, Representative Fowler Arthur was asked what was different about her bill and she responded,

“We really focus on defining the Marxist ideology…”^[1] When asked to define what Marxist ideology was, Representative Fowler Arthur said that “those are specifically that one nationality, color, ethnicity, race, or sex is inherently superior to another nationality, color, ethnicity, race, or sex… So the main goal of this definition of divisive concepts is to define the ideology behind some of these Marxist ideals…”^[2]

Fowler Arthur may be forgiven for ginning up neo-McCarthyism with such weird and wildly inaccurate characterizations of Marxism, as she herself never went to college, and, in fact, never spent a day in a school as she was homeschooled on her Rock Creek egg farm.^[3] But her bill should be taken seriously, not merely for the harm it may do to Ohio colleges and universities, but also because it is just the tip of the iceberg, or better, the feather poking from the guano pile, that is contemporary cultural conservatism.

H.B. 327, like similar bills in other states, is modelled on Trump’s Executive Order issued the last week before election day that purported to “combat” the indoctrination of government employees and contractors into the “malign ideology” of critical race theory by “woke” warriors. It variously libels critical race studies as advocating that races are essential and some races are superior to others while legislating the whitewashing of America and punishing its critics. One of its only differences in substance, besides more effectively including higher education, is that it does not make the legal unforced error of outlawing the New York Times 1619 Project, litigation bait that other states will have to defend. Rather, the bill itself is less interesting than its sponsor, a figure who symbolizes what the coattails of Trumpism has raised to power: a literally unschooled leader who has chosen as her legislative mission defining what can be taught in Ohio.

Fowler Arthur launched her political career by running for a seat on the Ohio State Board of Education in 2013. During her years as a member of the Ohio State Board of Education and chair of its Teaching, Leading and Learning Committee, Fowler Arthur’s main contribution was unsuccessfully attempting to rewrite the state’s mandated curriculum. Though her proposals were voted down, her deletions and additions are a terrifying window into the thinking of contemporary American authoritarianism.^[4]

Currently, Ohio’s first grade teachers are directed that “As children work and play collaboratively, they understand the importance of fair play, good sportsmanship, respect for the rights and opinions of others, and the idea of treating others the way they want to be treated. This builds to an understanding of perspective and concern for the common good.” Arthur deleted the words “fair play” and substituted “courtesy”. The last phrase, “and concern for the common good” was struck out as well. (The phrase “common good” is also excised from second grade guidelines while third graders are not to be told that citizenship is meant to promote the “the well-being of the whole community.” Eighth graders are not to be told that the “exercise of rights must be balanced…by the common good.”)

Substituting “courtesy” for “fair play” and eliminating the promotion of the “common good” is an attempt to write competitive individualism into schoolyard ethics. “Fair play” is, after all, a notion that some means of getting ahead of others are wrong while the “common good” presupposes that the point of work and play is to benefit everyone. Rather than treating others “fairly” this mode of conservative thinking is satisfied with treating them courteously, stepping over them with good graces, saying a sweet “have a blessed day” when stealing their lunch money.

Such thinking is underscored as a few paragraphs later the reason why first graders should be taught fair play is also stripped out. Instead of mandating that “Students understand that rules need to be fair” and that fair “means justice for all parties and concern for the fair allocation of resources among diverse members of a community,” six-year-olds are to be taught to obey rules because breaking them will hurt. “Rules are established for safety, order, and justice. Justice means that each person gets what they deserve. This is why there are consequences to breaking the law or rules,” Arthur’s substitute sounds more authentic in German.

Likewise, presently, third-graders are taught that government makes and carries out laws to protect individual rights that “should focus on being safe and secure.” Fowler Arthur’s red pencil strikes that, leaving government simply to exist to ensure order and security.

In Ohio, state history is first presented to fourth graders, and here Fowler Arthur and her collaborators take what at first glance appears to be a head-scratching objection to Buckeye origins. They delete that “The Northwest Ordinance incorporated democratic ideals into the territories” and replace it with “The Northwest Ordinance incorporated democratic ideals to establish a republican style of government.” Seemingly a trivial matter of wording, this change twists the curriculum in an authoritarian direction, because to dictators democracy is not a goal or an intrinsic value but only at best a mechanism of government. Children should not be taught to love democracy, but only to respect a system of representative government.

A similar addition to the guidelines for teaching about government follows this same hobnailed logic. Unsatisfied with a tripartite definition of common governments (democracy, dictatorship, and monarchy), Fowler Arthur adds two others, “Constitutional Republic,” which she defines as “representatives are elected by the people to make public policy decisions on their behalf, rather than by a direct vote,” and “Autocracy,” which is “absolute rule by a self-appointed ruler with unlimited authority.” Where students may today be led to look kindly on “democracy” when faced with the two other choices of “dictatorship” and “monarchy,” with these additions, democracy recedes and even dictatorship’s reputation is burnished in comparison with “autocracy.” Clearly, the Fowler Arthurites wish students to consider the “Constitutional Republic” favorably as its definition is far longer and more detailed than the others.

Fowler Arthur’s discomfort with democracy becomes more pronounced as students advance through their levels. By grade six, she can’t stomach calling the USA a democracy at all. In standards for students being able to give examples of different forms of government, the USA is dropped as the sole example of a democracy and replaced with… wait for it…  France! Instead, the United States is listed as an example of the newly added governmental form, the “constitutional republic” which is a “limited democratic government” in which lawmakers “make decisions on public policy for the people.”

For all their claims of color-blindness, Fowler Arthur and her anti-anti-racist warriors are quite fearful of teaching young students about different cultures or the history of racial oppression. Second grade teachers are not to be encouraged to have “cultural groups” from the “local community” come and show and tell “world cultures” as they now are. Seventh graders are not to be taught that Europeans “weakened and supplanted” the “established cultures” of indigenous peoples, rather they are to be taught that when the Europeans came “there was an amalgamation of cultures.” The Civil Rights movement was not about ending a system of racial injustice but, rather, “Dr. Martin Luther King sought a peaceful end to racial tensions.” It wasn’t just suffragists and NOW that fought for women’s rights, but so did Phyllis Schlafly’s Eagle Forum.

Weirdly, Fowler Arthur mandates that schools teach about the “Barbary Wars” when discussing Jefferson’s presidency, perhaps because TJ sent the marines to kill Muslims. I speculate here, but only because it follows a theme as the old instruction to tell students that the attacks on America on Sept. 11, 2001 led to “an increase in Islamophobia and xenophobia” is also removed.

Environmentalism is targeted as well, as second graders are not to be told that dams may “destroy animal habitats” but instead may “alter” them. Sixth graders are not to be taught that “many of the issues facing the world today” are the result of “human activities including pollution and disruption of habitat,” but only that “some” of them are. Children are not to be taught about “the shrinking of the Amazon rainforest due to deforestation.” References in current Ohio curricular guidelines to the polio vaccine or the birth control pill, are deleted, while references to the Second Amendment and gun rights are inserted throughout.

Critical thinking is under attack as the unit on teaching eighth graders how to evaluate historical sources is watered down. Rather than having students learn to evaluate historical accounts by evaluating the consistency of arguments, the perspectives and biases of authors, and cross-checking information with other “credible sources”, Fowler Arthur’s additions tell students to trust “eye witness accounts” and “source documents,” in other words, to trust anecdotal information without the rigors of evaluating their context.

Rather than have students think creatively about their government by being given an assignment to “devise and implement a plan to address a problem by engaging either the political process or the public policy process,” students should regurgitate how government works, or in Fowler Arthur’s words, “explain the process for civic engagement through either the political process or public policy process.” This same directive is repeated instead of having students think about how they would construct an argument for a “political party or interest group.”

The social vision of Fowler Arthur and her fellow culture war conservatives is rather transparent: those lucky enough to climb over their peers and be recognized as worthy citizens should follow the rules and do as their representatives tell them. Those who would promote divisive concepts such as democracy, the “common good,” thinking critically and objectively, or examining the past without national or racial bias, need to be silenced by the rules of government. But when firing teachers, be sure and be courteous. Have a blessed day.

https://www.counterpunch.org/2021/06/18/anti-critical-race-theory-and-neo-mccarthyism/

Notes.

^[1] H.B. No. 237 press conference June 15, 2021. https://ohiochannel.org/video/press-conference-6-15-2021-discussing-h-b-no-327?fbclid=IwAR00pKOucypIJcPKMYnOlmqg-i6uE8_OvKU9MjXyDNIUcmsBE6J1ndqTgXQ time mark 1:50

^[2] Ibid., time mark 6:00

^[3] https://www.beaconjournal.com/article/20131117/NEWS/311179380

^[4] http://education.ohio.gov/getattachment/State-Board/State-Board-Meetings/State-Board-Meetings-for-2019/June-2019-MEETING-Minutes-Final.pdf.aspx?lang=en-US pp. 54-61.

Consequências do aquecimento global - transbordamento costeiro em todo o mundo

 Uma aceleração do transbordamento costeiro em todo o mundo, por Institut de recherche pour le développement, 18 de junho de 2021

As regiões costeiras baixas hospedam quase 10% da população mundial. A combinação de
- aumento do nível do mar,
- marés,
- tempestade e
- ondas
aumentou o transbordamento da proteção costeira natural e artificial em quase 50% nas últimas duas décadas. A revelação vem de um estudo internacional coordenado pelo IRD, envolvendo parceiros internacionais. O estudo foi publicado na Nature Communications em 18 de junho de 2021.

Ao combinar dados de satélite e modelos digitais, os pesquisadores mostraram que o transbordamento costeiro e, consequentemente, o risco de inundações, deve acelerar ainda mais ao longo do século 21, em até 50 vezes em um cenário de aquecimento global de alta emissão, especialmente no trópicos. Esse aumento é causado principalmente por uma combinação da elevação do nível do mar e das ondas do mar.


Além de
- erosão contínua e
- elevação do nível do mar,
essas áreas e seus ecossistemas únicos estão enfrentando riscos destrutivos, incluindo inundações episódicas devido ao transbordamento da proteção natural / artificial, como no caso do furacão Katrina, que atingiu os Estados Unidos em 2005, o ciclone Xynthia na Europa em 2010 e o tufão Haiyan em Ásia em 2013 (o maior ciclone tropical já medido).

Espera-se que esses eventos episódicos se tornem mais graves e mais frequentes devido ao aquecimento global, enquanto as consequências também aumentarão devido a
- aumento da pressão antropogênica, como
- desenvolvimento costeiro e
- desenvolvimento de infraestrutura,
- rápida urbanização.
Embora a magnitude e a frequência desses eventos permaneçam incertas, os cientistas acreditam que os países nos trópicos serão particularmente afetados.

Apesar do papel significativo das ondas do mar na determinação dos níveis do mar costeiro, sua contribuição para as inundações costeiras tinha sido amplamente negligenciada, principalmente devido à falta de informações topográficas costeiras precisas.

Medir eventos passados ​​para estimar riscos futuros

Neste estudo, pesquisadores franceses do IRD, CNES, Mercator Océan, juntamente com colegas holandeses, brasileiros, portugueses, italianos e nigerianos, combinaram um modelo digital global sem precedentes para elevação da superfície com novas estimativas dos níveis extremos do mar. Esses níveis extremos de água contêm marés, análise de ondas impulsionadas pelo vento e medições existentes de defesas costeiras naturais e artificiais.

O estudo começou quantificando o aumento de eventos de submersão global que ocorreram entre 1993 e 2015. Para isso, dados de satélite foram usados ​​para definir dois parâmetros-chave para a topografia costeira: a encosta da praia local e a elevação subaerial máxima das costas. O nível extremo das águas costeiras foi calculado em intervalos de tempo de hora em hora, a fim de identificar o número potencial anual de horas durante as quais as defesas costeiras poderiam ser ultrapassadas em cada área.

“A combinação de marés e episódios de ondas grandes é o principal contribuinte para episódios de transbordamento costeiro”, diz Rafaël Almar, pesquisador em dinâmica costeira do IRD e coordenador do estudo. “Identificamos pontos críticos, onde o aumento do risco de transbordamento é maior, como no Golfo do México, Sul do Mediterrâneo, Oeste da África, Madagascar e Mar Báltico”.

Aceleração durante o século 21

Os cientistas também realizaram uma avaliação global inicial do potencial transbordamento costeiro ao longo do século 21, levando em consideração diferentes cenários de elevação do nível do mar. Os resultados mostram que o número de horas de galgamento pode aumentar com um ritmo mais rápido do que a taxa média de aumento do nível do mar. “A frequência de transbordamento está se acelerando exponencialmente e será claramente perceptível já em 2050, independente do cenário climático. Até o final do século, a intensidade da aceleração dependerá das trajetórias futuras das emissões de gases de efeito estufa e, portanto, do aumento no nível do mar. No caso de um cenário de altas emissões, o número de horas de galgamento globalmente pode aumentar 50 vezes em comparação com os níveis atuais ", alerta Rafaël Almar.

Mais estudos serão necessários nos níveis local e regional para dar corpo a essas projeções globais, que fornecem uma base sólida para propor medidas de adaptação eficazes nos hotspots identificados.

"À medida que avançamos ao longo do século 21, mais e mais regiões serão expostas ao transbordamento e consequentes inundações costeiras, especialmente nos trópicos, noroeste dos Estados Unidos, Escandinávia e Extremo Oriente da Rússia."

Tradução: VanRes
Addapted from: https://phys.org/news/2021-06-coastal-overtopping-world.html

An acceleration of coastal overtopping around the world, by Institut de recherche pour le développement, 18 jun, 2021

Schematic diagram of coastal overtopping. Credit: © Rafaël Almar et al.,Nature Communications.

Low-lying coastal regions host nearly 10% of the world's population.

The combination of
- sea level rise,
- tides,
- storm surge and
- waves
has increased the overtopping of natural and artificial coastal protection by nearly 50% in the last two decades. This revelation comes from an international study coordinated by IRD, involving international partners . The study was published in Nature Communications on June 18th 2021.

By combining satellite data and digital models, the researchers have shown that coastal overtopping, and consequently the risk of flooding, is set to further accelerate over the 21st century, by up to 50-fold under a high emission global warming scenario, especially in the tropics. This increase is principally caused by a combination of sea level rise and ocean waves.

In addition to
- ongoing erosion and
- rising sea levels,
these areas and their unique ecosystems are facing destructive hazards, including episodic flooding due to overtopping of natural/artificial protection, as in the case of Hurricane Katrina, which hit the United States in 2005, Cyclone Xynthia in Europe in 2010, and Typhoon Haiyan in Asia in 2013 (the largest tropical cyclone ever measured).

These episodic events are expected to become more severe and more frequent due to global warming, while the consequences will also increase due to
- increased anthropogenic pressure, such as
- coastal development and
- infrastructure development,
- rapid urbanization.
Although the magnitude and frequency of these events remain uncertain, scientists believe that countries in the tropics will be particularly affected.

Despite the significant role ocean waves play in determining coastal sea levels, their contribution to coastal flooding had previously been largely overlooked, mainly due to a lack of accurate coastal topographic information.

Measuring past events to estimate future risks

In this study, French researchers from IRD, CNES, Mercator Océan, together with Dutch, Brazilian, Portuguese, Italian and Nigerian colleagues, combined an unprecedented global digital model for surface elevation with new estimates of the extreme sea levels. These extreme water levels contain tides, analysis of wind-driven waves and existing measurements of natural and artificial coastal defenses.

The study started by quantifying the increase in global submersion events that occurred between 1993 and 2015. To accomplish this, satellite data was used to define two key parameters for coastal topography: the local beach-slope and maximum subaerial elevation of the coasts. The extreme level of coastal waters was calculated in hourly timesteps in order to identify the potential annual number of hours during which coastal defenses could be overtopped in each area.

"The combination of tides and episodes of large waves is the main contributor to episodes of coastal overflow," says Rafaël Almar, a researcher in coastal dynamics at IRD, and the coordinator of the study. "We identified hot-spots, where the increase in risks of overtopping is higher, such as in the Gulf of Mexico, the Southern Mediterranean, West Africa, Madagascar and the Baltic Sea."

Acceleration during the 21st century

The scientists also performed an initial global assessment of the potential coastal overtopping over the 21st century, by taking into account different sea-level rise scenarios. Results show that the number of overtopping hours could increase with a faster pace than the average rate of sea-level rise. "The frequency of overtopping is accelerating exponentially and will be clearly perceptible as early as 2050, regardless of the climate scenario. By the end of the century, the intensity of the acceleration will depend on the future trajectories of greenhouse gas emissions and therefore the rise in sea-level. In the case of a high emissions scenario, the number of overtopping hours globally could increase fifty-fold compared with current levels," Rafaël Almar warns.

Further studies will be needed on the local and regional levels to flesh out these global projections, which provide a solid basis for proposing effective adaptation measures in the hotspots identified.

"As we go along the 21st century, more and more regions will be exposed to overtopping and consequent coastal flooding, especially in the tropics, north-western United States, Scandinavia, and the Far East of Russia."

https://phys.org/news/2021-06-coastal-overtopping-world.html