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

NC 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

地球经历了一段时间的变暖 冷却了整个历史。
 然而，在过去的几个世纪里， 全球气温急剧上升， 在地球的周期性规范之外。
 当大气温室气体释放时就会发生变暖, 就像二氧化碳被捕获一样 在地球和臭氧层之间。
 二氧化碳可以吸收太阳能 长红外波长， 阻止它返回外层空间， 从而提高了大气温度。
 虽然这是一个自然的过程 称为温室效应 二氧化碳的急剧增加 存在于地球大气层中 引起燃烧的煤和石油，不是。
 温度升高的结果 在世界各地都能看到。
 例如，在北极，极地冰盖正在融化 导致海平面上升和岛屿下沉。
 这不仅威胁到沿海城市， 但也可以增加发生率 极端气象事件，如干旱， 飓风，和暴风雨。
 许多动物的迁徙和繁殖模式 比几十年前发生得早 物种分布的规模也在减小。
 随着越来越多的怀疑者认识到全球变暖， 环保做法的增加 各行业可能提供机会 逆转人类的影响 帮助避免严重后果 全球气候变化。

Castellano， E.， S. Becagli， M. Hansson， M. Hutterli， JR Petit， MR Rampino， M. Severi， JP Steffensen， R. Traversi， 和 R. Udisti。"欧洲南极洲穹顶 C （EDC96） 冰芯冰芯项目硫酸盐地层中记录的全新世火山历史。"地球物理研究杂志:大气 110，第 D6 期（2005 年）。[<a href="https://doi.org/10.1029/2004JD005259" target="__blank">来源</a>]

Yang， Bao， Chun Qin， Jianglin Wang， Minhui He， Thomas M. Melvin， Timothy J. Osborn， and Keith R. Briffa.."青藏高原东北部年降水量的 3,500 年年轮记录。"美国国家科学院院刊 111，第 8 期（2014 年 2 月 25 日）:2903-8。[<a href="https://doi.org/10.1073/pnas.1319238111" target="__blank">来源</a>]

全球气候变化

在其约45亿年的历史中，地球经历了变暖和降温的时期。然而，目前全球气温的急剧上升远远超出了地球的循环规范，人类引起的全球气候变化的证据令人信服。古气候条件的古气候学通过比较近期的情况，为人类引起的全球气候变化提供了充分的证据。
<h4>过去的升温和降温时期</h4>

仅在过去的65万年里，冰川就经历了七次进退循环。11000多年前，最近的冰期突然结束，标志着我们现代气候时代的开始，即全新世地质时代。大多数历史性气候变化都与地球轨道的微小变化有关，这些变化改变了地球接收到的太阳辐射量。

<h4>古气候学</h4>

古气候学是研究整个地球地质过去的气候条件及其因果关系的学科。古气候学家运用各种科学方法来推断地球气候和大气系统的过去状况。

<h4>冰芯数据</h4>

从厚厚的山脉冰川和极地冰原上采集的冰芯样本可以揭示全球气候变化的信息。冰堆积的季节性停顿会导致冰芯中出现可观测的冰层。这些层可以用来建立年表，最底层是最古老的。然后，研究人员可以分析冰层的性质以及冰层内部的物质（如气泡、氧和氢同位素的比例），以重建地球的古代气候。欧洲南极冰芯取样项目分析了南极冰芯中的火山灰，提供了全新世火山历史的详细记录。这一记录揭示了全新世期间的96次喷发，其中33次喷发发生在过去2000年。

<h4>树状气候学</h4>

科学家还可以通过研究年轮来研究过去的气候，这一领域被称为树状气候学。从本质上讲，树木年轮在有利的条件下更宽，在恶劣的环境下更窄。树木年轮可以通过将年轮从一个样本匹配到另一个样本（甚至是考古挖掘的样本）来精确地确定年代。虽然树木气候学有局限性，树轮是有用的气候代理，可以用来创建高分辨率的气候记录特定的地理位置。"

在大约45亿年的历史中，地球经历了多次变暖与变冷的时期。然而，当前全球气温的急剧上升……

Education

教育

JoVE Core

生物学

Ecology

生态学

Biodiversity and Conservation

生物多样性与保护

KEY TERMS AND CONCEPTS

关键术语与概念

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系列通过300多节动画视频课简明易懂地讲解生物学中的关键概念，以及150余段视频展示科学家在现代实验室开展实际研究实验，让生物学变得平易近人。

Ancient Clues to Climate Change

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