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

- [Narrador] La tierra
ha sufrido un período de

calentamiento y enfriamiento
a lo largo de su historia.

Sin embargo, durante los últimos siglos,

ha habido un aumento drástico
en las temperaturas globales,

fuera de las normas cíclicas de la tierra.

El calentamiento ocurre
cuando los gases de efecto

invernadero atmosféricos,

como el dióxido de
carbono quedan atrapados

entre la tierra y la capa de ozono.

El dióxido de carbono puede
absorber la energía solar

de largas longitudes de onda infrarrojas,

evitando que regrese al espacio exterior,

lo que aumenta las
temperaturas atmosféricas.

Si bien es un proceso natural

llamado efecto invernadero,

el fuerte aumento en la
cantidad de dióxido de carbono

presente en la atmósfera de la tierra

causada por la quema de
carbón y petróleo, no lo es.

Los resultados de este
aumento de temperatura

se pueden ver en todo el mundo.

Por ejemplo, en el Ártico,
los casquetes polares se están

derritiendo, lo que se traduce
en un aumento del nivel

del mar y la inmersión en una isla.

Esto no solo amenaza a
las ciudades costeras,

sino que también puede
aumentar la ocurrencia

de eventos meteorológicos
extremos, como sequías,

huracanes y tormentas severas.

También los patrones de migración
y reproducción de muchos

animales están ocurriendo más
temprano en el año que hace

décadas y el tamaño de las
distribuciones de las especies

está disminuyendo.

A medida que el calentamiento
global es reconocido por más

escépticos, el aumento de
las prácticas amigables

con el medio ambiente por
parte de las industrias puede

brindar oportunidades para
revertir el impacto humano

y ayudar a evitar las consecuencias graves

del cambio climático global.

Castellano, E., S. Becagli, M. Hansson, M. Hutterli, J. R. Petit, M. R. Rampino, M. Severi, J. P. Steffensen, R. Traversi y R. Udisti. "Historia volcánica del Holoceno registrada en la estratigrafía de sulfatos del Proyecto Europeo para la extracción de muestras de hielo en el núcleo de hielo del Domo C de la Antártida (EDC96)". Revista de Investigación Geofísica: Atmósferas 110, no. D6 (2005). [<a href="https://doi.org/10.1029/2004JD005259" target="__blank">Fuente</a>]

Yang, Bao, Chun Qin, Jianglin Wang, Minhui He, Thomas M. Melvin, Timothy J. Osborn y Keith R. Briffa. "Un registro de 3.500 años de precipitación anual en la meseta tibetana nororiental". Actas de la Academia Nacional de Ciencias 111, no. 8 (25 de febrero de 2014): 2903-8. [<a href="https://doi.org/10.1073/pnas.1319238111" target="__blank">Fuente</a>]

cambio climático global

A lo largo de sus 4.500 millones de años de historia, la Tierra ha experimentado períodos de calentamiento y enfriamiento. Sin embargo, el aumento actual de las temperaturas globales es excepcional y está fuera de los ciclos naturales del planeta. La evidencia del cambio climático causado por el ser humano es contundente. La paleoclimatología, el estudio de los climas antiguos, permite comparar las condiciones recientes con las del pasado, confirmando estos cambios. <h4>Períodos pasados de calentamiento y enfriamiento</h4> En los últimos 650.000 años, la Tierra ha atravesado siete ciclos de avance y retroceso glaciar. Hace más de 11.000 años, la última era de hielo terminó abruptamente, marcando el inicio del Holoceno, nuestra época climática actual. La mayoría de los cambios climáticos históricos se relacionan con variaciones en la órbita terrestre, que afectan la radiación solar recibida. <h4>Paleoclimatología</h4> La paleoclimatología estudia las condiciones climáticas del pasado y sus causas. Para ello, los científicos emplean diversos métodos que permiten reconstruir la evolución del clima terrestre. <h4>Datos del núcleo de hielo</h4> Las muestras de núcleos de hielo extraídas de glaciares y capas de hielo polares proporcionan información clave sobre el cambio climático. Las pausas estacionales en la acumulación de hielo generan capas observables, donde las inferiores son las más antiguas. Analizando el hielo y los materiales atrapados en su interior, como burbujas de aire y proporciones de isótopos de oxígeno e hidrógeno, los investigadores pueden reconstruir climas antiguos. El Proyecto Europeo para la extracción de muestras de hielo en la Antártida examinó cenizas volcánicas atrapadas en estos núcleos, revelando 96 erupciones en el Holoceno, 33 de ellas en los últimos 2.000 años. <h4>Dendroclimatología</h4> El análisis de los anillos de crecimiento de los árboles, conocido como dendroclimatología, también permite estudiar el clima pasado. Los anillos son más anchos en condiciones favorables y más estrechos en épocas difíciles. Su estudio permite dataciones precisas y comparaciones entre muestras, incluso de restos arqueológicos. Aunque tiene limitaciones, la dendroclimatología es una herramienta valiosa para generar registros climáticos detallados de regiones específicas.

Cambio climático global

A lo largo de sus ~4.5 mil millones de años de historia, la Tierra ha experimentado períodos de calentamiento y enfriamiento. Sin embargo, el drástico aumento actual de ...

Education

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Biología

Ecology

Ecología

Biodiversity and Conservation

Biodiversidad y conservación

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

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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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

JoVE Core Biología da vida a la biología a través de una serie con más de 300 lecciones de vídeo animadas, concisas y fáciles de entender, que explican conceptos clave de la biología, incluyendo también más de 150 vídeos de científicos en acción, que muestran experimentos reales realizados en laboratorios actuales de investigación.

Ancient Clues to Climate Change

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