Name: ancient clues to climate change
Uploaded: 2019-03-11T09:21:43.000Z
Duration: 1 min 50 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Biology

ecosystems-interactions-energy-and-dynamics

Ecosystems- Interactions, Energy, and Dynamics

LS.Bio.5.2

Global Climate Change

A terra passou por períodos de aquecimento e resfriamento ao longo de sua história. No entanto, nos últimos séculos, houve um aumento drástico em temperaturas globais fora das normas cíclicas da Terra. O aquecimento ocorre quando gases atmosféricos de efeito estufa como o dióxido de carbono ficam presos entre a terra e a camada de ozônio.O dióxido de carbono pode absorver energia solar de comprimentos de onda infravermelhos longos, a impedindo de viajar de volta para o espaço sideral, aumentando assim as temperaturas atmosféricas. Embora este seja um processo natural chamado de efeito de estufa, o aumento acentuado e a quantidade do dióxido de carbono presente na atmosfera da terra causado pela queima de carvão e petróleo, não é. Os resultados desse aumento de temperatura podem ser vistos em todo o mundo.Por exemplo, no Ártico, calotas polares estão derretendo, resultando no aumento do nível do mar e na submersão de ilhas. Isso não ameaça apenas as cidades costeiras, mas também pode aumentar a ocorrência de eventos meteorológicos extremos, como secas, furacões e tempestades severas. Além disso, padrões de migração e reprodução de muitos animais estão ocorrendo mais cedo no ano do que há décadas e o tamanho e distribuição das espécies estão diminuindo.Conforme o aquecimento global passa a ser reconhecido por mais céticos, o incremento ambientalmente amigável de práticas por parte das indústrias podem fornecer oportunidades para reverter os impactos humanos e ajudar a evitar consequências graves das alterações climáticas globais.

Castellano, E., S. Becagli, M. Hansson, M. Hutterli, J. R. Petit, M. R. Rampino, M. Severi, J. P. Steffensen, R. Traversi e R. Udisti. "História vulcânica do Holoceno registrada na estratigrafia de sulfato do Projeto Europeu de Perfuração de Gelo no Núcleo de Gelo da Cúpula C da Antártica (EDC96)." Jornal de Pesquisa Geofísica: Atmosferas 110, nº D6 (2005). [<a href="https://doi.org/10.1029/2004JD005259" target="__blank">Fonte</a>]

Yang, Bao, Chun Qin, Jianglin Wang, Minhui He, Thomas M. Melvin, Timothy J. Osborn e Keith R. Briffa. "Um registro de anéis de árvores de 3.500 anos de precipitação anual no planalto tibetano do nordeste." Anais da Academia Nacional de Ciências 111, nº 8 (25 de fevereiro de 2014): 2903–8. [<a href="https://doi.org/10.1073/pnas.1319238111" target="__blank">Fonte</a>]

alterações climáticas globais

Ao longo dos seus ~4,5 mil milhões de anos de história, a Terra passou por períodos de aquecimento e arrefecimento. No entanto, o atual aumento drástico das temperaturas globais está bem fora das normas cíclicas da Terra, e as evidências para as alterações climáticas globais causadas pelo homem são convincentes. A paleoclimatologia, o estudo das condições climáticas antigas, fornece amplas evidências para as alterações climáticas globais causadas pelo homem, comparando as condições recentes com as do passado.
 
 <h4>Períodos de Aquecimento e Arrefecimento do Passado</h4>
 
 Só nos últimos 650.000 anos, houve sete ciclos de avanço e recuo glacial. Há mais de 11.000 anos, a era glacial mais recente terminou abruptamente—marcando o início de nossa era climática moderna, a época geológica do Holoceno. A maioria das alterações climáticas históricas estão associadas a pequenas variações na órbita da Terra que alteraram a quantidade da radiação solar recebida pela Terra.
 
 <h4>Paleoclimatologia</h4>
 
 A paleoclimatologia é o estudo das condições climáticas e as suas causas e efeitos em todo o passado geológico da Terra. Paleoclimatologistas empregam uma variedade de métodos científicos para deduzir as condições passadas do clima e do sistema atmosférico da Terra.
 
 <h4>Dados de Núcleos de Gelo</h4>
 
 Amostras de núcleos de gelo colhidas de espessos glaciares montanhosos e mantos polares de gelo podem revelar informações sobre as alterações climáticas globais. Pausas sazonais na acumulação de gelo podem levar a camadas observáveis em núcleos de gelo. Essas camadas podem ser usadas para estabelecer uma cronologia, sendo as camadas mais inferiores as mais antigas. Os investigadores podem então analisar as propriedades do gelo e do material preso dentro dele (por exemplo, bolhas de ar e proporções de isótopos de oxigénio e hidrogénio) para reconstruir o clima antigo da Terra. O Projeto Europeu de Núcleos de Gelo na Antártida analisou cinzas vulcânicas presas em núcleos de gelo da Antártida para fornecer um registo detalhado da história vulcânica do Holoceno. Este registo revelou 96 erupções durante o Holoceno, com 33 dessas erupções ocorrendo durante os últimos 2.000 anos.
 
 <h4>Dendroclimatologia</h4>
 
 Os cientistas também podem estudar o clima passado examinando anéis de árvores anuais—um campo chamado de dendroclimatologia. Essencialmente, os anéis das árvores são mais largos em condições favoráveis e mais estreitos durante alturas severas. Os anéis das árvores podem ser datados com precisão combinando anéis de amostra para amostra—até mesmo de amostras de escavações arqueológicas. Embora a dendroclimatologia tenha limitações, os anéis das árvores são indicadores climáticos úteis que podem ser usados para criar registos climáticos de alta resolução para locais geográficos específicos.

Alterações Climáticas Globais

Ao longo de sua história de ~ 4,5 bilhões de anos, a Terra experimentou períodos de aquecimento e resfriamento. No entanto, o atual aumento drástico no mercado global ...

Education

JoVE Core

Biologia

Ecology

Ecologia

Biodiversity and Conservation

Biodiversidade e Conservação

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

ancient clues to climate change

Ancient climate clues help scientists track global climate change. Paleoclimatology is the study of climate conditions in Earth’s past and the causes and effects behind them. By comparing recent climate patterns with older records, researchers can find strong evidence for human-caused warming.

Earth’s climate has changed many times over its 4.5 billion year history. In the last 650,000 years, there have been seven cycles of glacial advance and retreat. The most recent ice age ended more than 11,000 years ago and began the Holocene, the modern climate era. Many earlier changes were linked to small shifts in Earth’s orbit that altered the amount of solar radiation reaching the planet.

Paleoclimatologists use several scientific methods to study the past climate and atmosphere. One major source is ice core data from thick mountain glaciers and polar ice sheets. Seasonal pauses in ice buildup create layers in the ice, and the lowest layers are the oldest. Scientists can study the ice itself and the trapped material inside it, such as air bubbles and ratios of oxygen and hydrogen isotopes, to reconstruct ancient climate conditions.

Ice cores can also preserve volcanic ash. The European Project for Ice Coring in Antarctica used ash trapped in Antarctic ice cores to build a detailed record of Holocene volcanic history. That record showed 96 eruptions during the Holocene, including 33 eruptions in the last 2,000 years. Another useful climate proxy is tree rings. Dendroclimatology, the study of annual tree rings, shows that rings are wider in favorable conditions and narrower in harsh ones. Tree rings can be matched and dated across samples, even from archaeological digs, and they help create high-resolution climate records for specific places, although the method has limits.

Ancient Clues to Climate Change

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global climate change

Ancient climate clues help scientists track global climate change. Paleoclimatology is the study of climate conditions in Earth’s past and the causes and effects behind them. By comparing recent climate patterns with older records, researchers can find strong evidence for human-caused warming. Earth’s climate has changed many times over its 4.5 billion year history. In the last 650,000 years, there have been seven cycles of glacial advance and retreat. The most recent ice age ended more than...

what is biodiversity?

Biodiversity Across Genes, Species, and Ecosystems

Biodiversity is the variety of living things at the genetic, species, and ecosystem levels. It includes not only how many kinds of organisms exist, but also how they are related and how they interact with the world around them. Species diversity spans the full evolutionary tree. It includes single-celled prokaryotes such as bacteria and archaea, as well as the eukaryotic kingdoms: plants, animals, fungi, and protists. About 1.75 million species have been identified so far, and scientists...

threats to biodiversity

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Human activity is changing biodiversity and pushing Earth toward a sixth extinction event. Earlier mass extinctions ended many species, and then new species spread into the changed environment. Today, the Holocene epoch is seeing a mass extinction linked to human actions, and it is often called the Anthropocene. Human numbers and human biomass show how large this impact has become. In 2019, the human population reached 7.7 billion and is projected to rise to 10 billion by 2060. By biomass,...

conservation of declining populations

Saving Species Through Population Recovery

Conservation of declining populations focuses on detecting a population drop, finding its cause, and stopping further loss. The goal is to prevent extinction by using scientific methods to identify the agents behind the decline. Once the cause is known, conservation teams can remove, oppose, or neutralize it. A common step is to test possible causes with a small trial group. If the cause is confirmed, the remaining animals may be moved to an unaffected area. When the population is too small or...

biodiversity and human values

Biodiversity in Food, Tools, and Medicine

Biodiversity supports human life through food, tools, medicine, and many other needs. Changes in the variety of species can also change the environment. Those environmental shifts can alter weather patterns and affect human civilizations. People have depended on biodiversity for agriculture since early human history. Agriculture began when ancestral humans found species that were good sources of food. At least 11,000 years ago, people started selecting plant and animal species to raise on...

what is conservation biology?

Protecting Biodiversity in Conservation Biology

Conservation biology is the science of protecting biodiversity and keeping ecosystems healthy. It looks at how living things, habitats, and human needs are connected. The goal is to preserve biodiversity so ecosystems can continue to function well. Healthy ecosystems provide people with important natural resources. These include food, medicines, and building materials. Ecosystems also deliver key services, such as cleaning air and water. Evidence shows that these services depend on...

what is climate?

Climate Patterns and Earth’s Energy Balance

Climate describes the usual weather conditions in a place over a long period of time. The idea is simple: climate is what you expect, while weather is what you get. Climate is shaped by geographic factors such as latitude, terrain, and how close an area is to bodies of water. Weather and climate are related, but they work on different time scales. Weather is the state of the atmosphere at a specific time and place. Climate is the average pattern of weather over much longer periods. Because of...

sustainable development

Protecting Oceans for Sustainable Development

Sustainable development depends on protecting oceans while meeting human needs. As the human population grows and uses more resources, people must stay aware of the planet’s natural limits. The goal is to improve life now without taking away the resources future generations will need. Long-term sustainability depends on understanding how human actions affect ecological systems. Oceans are a major part of this balance. They provide food for people, produce much of the atmosphere’s oxygen, and...

conservation of small populations

Saving Small Populations with Genetic Diversity

Small populations can be hard to save because they often lose genetic diversity. When variation is low, a species has fewer traits that may help it adapt to climate change, competition from other species, or new diseases. That makes extinction more likely. Large populations usually have a better chance of surviving new stresses. They are more likely to include individuals with genetic variants that are helpful in changing conditions. Small populations are much less likely to contain this kind...

habitat fragmentation

How Fragmented Habitats Affect Wildlife

Habitat fragmentation breaks one continuous habitat into smaller, separate patches. Human land conversion is a major cause of this change, and slower geological shifts in the physical environment can also fragment habitats. The process usually follows the same stages: perforation, dissection, fragmentation, shrinkage, and attrition. Perforation and dissection often begin during land development. Perforation happens when undeveloped land is cleared for something like a home, and dissection...

key terms and concepts

Explore how ice cores and tree rings reveal Earth’s past climate. Learn how paleoclimatology helps scientists study ancient warming, cooling, and volcanic history.

Ancient Clues to Climate Change | JoVE K12

JoVE Core series brings biology to life through over 300 concise and easy-to-understand animated video lessons that explain key concepts in biology, plus more than 150 scientist-in-action videos that show actual research experiments conducted in today’s laboratories.

biology

A coleção JoVE Core dá vida à biologia através de mais de 300 vídeos de animação concisos e fáceis de entender que explicam conceitos-chave de biologia, além de mais de 150 vídeos de Cientistas em ação que mostram experimentos reais em pesquisa realizados nos laboratórios atualmente.

Ancient Clues to Climate Change

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