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

地球は歴史を通じて 温暖化と冷却の時期を経験してきました しかし過去数世紀にわたり 地球の周期的な基準をこえて 地球の気温が急激に上昇しています 二酸化炭素などの温室効果ガスが 地球とオゾン層の間に閉じ込められると 温暖化が生じます 二酸化炭素は 長い赤外波長の太陽エネルギーを吸収し それが宇宙空間に戻るのを防ぎ 気温を上昇させます これは温室効果と呼ばれる自然な過程ですが 石炭や石油の燃焼によって引き起こされる 地球の大気中に存在する 二酸化炭素の量の急激な増加は そうではありません この温度上昇による結果は 世界中で見られています 例えば 北極圏では 極地の氷冠が溶けて 海面が上昇し 島が水没しています これは沿岸都市を脅かすだけでなく 干ばつ ハリケーン 激しい暴風雨などの 極端な気象事象の発生が 増加する場合があります また多くの動物の移動と 繁殖のパターンが数十年前に比べて 一年の早い時期に生じています そして種分布のサイズは減少しています より多くの懐疑論者が 地球温暖化を認識するにつれ 産業における環境に優しい慣行が増加し 人間による影響を逆転させ 世界的な気候変動の深刻な影響を 回避する機会となるかもしれません

Castellano, E., S. Becagli, M. Hansson, M. Hutterli, J. R. Petit, M. R. Rampino, M. Severi, J. P. Steffensen, R. Traversi, and R. Udisti. "Holocene Volcanic History as Recorded in the Sulfate Stratigraphy of the European Project for Ice Coring in Antarctica Dome C (EDC96) Ice Core." Journal of Geophysical Research: Atmospheres 110, no. D6 (2005).[<a href="https://doi.org/10.1029/2004JD005259" target="__blank">ソース</a>]

Yang, Bao, Chun Qin, Jianglin Wang, Minhui He, Thomas M. Melvin, Timothy J. Osborn, and Keith R. Briffa. "A 3,500-Year Tree-Ring Record of Annual Precipitation on the Northeastern Tibetan Plateau." 全米科学アカデミー紀要 111, no. 8 (2014年2月25日): 2903–8.[<a href="https://doi.org/10.1073/pnas.1319238111" target="__blank">ソース</a>]

地球規模の気候変動

地球は約45億年の歴史の中で、温暖化と寒冷化を繰り返してきました。しかし、現在の地球の気温の急激な上昇は、地球の周期的な規範を大きく逸脱しており、人為的に地球の気候変動を引き起こしたことを示す証拠は明白です。古気候学（古代の気候状態を研究する学問）は、最近の状態を過去の状態と比較することで、人為的な地球気候変動の十分な証拠を提供しています。
 
 <h4>過去の温暖化と寒冷化の時期</h4>
 
 過去65万年の間だけでも、氷河の前進と後退が7回繰り返されています。11,000年以上前に、最も新しい氷河期が突然終わり、現代の気候時代である完新世が始まりました。歴史的な気候変動のほとんどは、地球の軌道のわずかな変動によって地球が受ける太陽放射の量が変化したことに関連しています。 
 
 <h4>古気候学</h4>
 
 古気候学は、地球の地質学的過去における気候条件とその原因および影響を研究する学問です。古気候学者は、さまざまな科学的手法を用いて、地球の気候と大気システムの過去の状態を推測します。 
 
 <h4>アイス・コア・データ</h4>
 
 厚い山の氷河や極地の氷床から採取されたアイスコアサンプルは、地球の気候変動に関する情報を明らかにします。氷の蓄積が季節的に停止すると、アイスコアに観測可能な層ができます。これらの層を利用して、最も低い層が最も古いという年代を確立できます。研究者は、氷とその中に閉じ込められた物質の特性（気泡、酸素と水素の同位体比など）を分析して、地球の古代の気候を復元できます。European Project for Ice Coring in Antarcticaでは、南極のアイスコアに閉じ込められた火山灰を分析し、完新世の火山の歴史を詳細に記録しました。この記録によると、完新世には96回の噴火があり、そのうち33回は過去2,000年の間に発生していることがわかりました。
 
 <h4>年輪気候学</h4>
 
 科学者は、年輪を調べることで過去の気候を調べることができますが、これは「年輪気候学」と呼ばれる分野です。木の年輪は、好条件の時には広く、悪条件の時には狭くなります。木の年輪は、サンプルとサンプルの年輪を照合することで、正確な年代を特定できますが、これには考古学的に発掘されたサンプルも含まれます。年輪気候学には限界がありますが、樹木の年輪は有用な気候プロキシであり、特定の地理的場所の高解像度の気候記録を作成するために使用できます。

~45億年の歴史を通じて、地球は温暖化と寒冷化の時代を経験してきました。しかし、現在の世界的な激減...

Education

JoVE Core

生物学

Ecology

生態学

Biodiversity and Conservation

生物多様性と保全

KEY TERMS AND CONCEPTS

主要用語と概念

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

what is weather?

How Sunlight Shapes Daily Weather

Weather is the current state of the atmosphere at a specific time and place. It is temporary and changes from one location to another. Weather is shaped by the interaction of the sun, atmosphere, hydrosphere, and geosphere. Solar radiation reaches Earth and interacts with water and land. These surfaces release that energy as thermal radiation, or heat, which warms the air above them. Some of that heat escapes back into space, but some is trapped by atmospheric gases. This heat retention is...

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

How Humans Change Biodiversity

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

JoVE Core シリーズは、生物学の重要な概念を説明する 300 を超える簡潔でわかりやすいアニメーション ビデオ レッスンに加え、今日の研究室で行われる実際の研究実験を示す 150 以上の科学者の活動ビデオを通じて、生物学に命を吹き込みます。

Ancient Clues to Climate Change

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