SOCIAL SCIENCE - ACADEMIC DECATHLON 2024-2025

thermosphere

80-90 to 800 km, -86.5°C to 1200°C, second-most outer layer of the atmosphere, the layer of the Auroras

The Single System

ESS defines the factors of climate and the entire world as an understandable single system, with many subsystems that interact to shape weather and climate. Affected by "forcings."

Subsystems of ESS

geosphere (earth and rock), hydrosphere (water and ice), atmosphere (air), and biosphere (living organisms).

Forcings

the external forces that alter the balance of subsystems & stability of weather + climate. Alterations often cause reactions (positive or negative feedback)

Scales

the level at which Earth's subsystems interact with each other; Example: hydrosphere interacts on a large scale (ocean) and small scale (stream), changing the moisture levels

Geosphere (a.k.a. Lithosphere)

The subsystem that encompasses all the land, earth, and rock of Earth and can impact weather and climate (e.g. mountain ranges cause cloud formation, volcano eruptions release gases and particles for climate change)

Geological time scale

the millions and billions of years for the Earth to move and change form, such as plate shifting, release of minerals; Earth's crust has the most interactions between geosphere and other subsys.

Hydrosphere

The subsystem with all the water in Earth, the ground, and atmosphere. (e.g. oceans, lakes, clouds, water vapor, and even ice).

Often focused on with climate change (warming oceans, rising sea level, droughts, flooding)

Cryosphere

a termed subsystem that includes all the ice on Earth, and is also discussed with climate change (e.g. melting of cryosphere at N. & S. Poles)

Atmosphere

the subsystem that consists of many gases and atmospheric zones/layers (prev. discussed), as well as involves the greenhouse gas effect

Greenhouse gas effect

a phenomenon where the concentration of certain gases released by other subsystems traps heat in the lower atmosphere

1. Certain gases transparent to Sun rays let the rays reach the surface.
2. Re-radiated rays lose energy and become infrared.
3. At the infrared level, greenhouse gases absorb & trap that heat.

Biosphere

the subsystem consisting of all living things on, in, and around Earth; life can affect thermal constitution of Earth's subsystems (e.g. Humans affecting carbon cycle by breathing, plants produce oxygen from carbon dioxide, fossil fuels accelerate Earth's carbon cycle and carbon level)

Influential forcings

solar energy, volcanoes, and greenhouse gases; for example, the climate system is an open system, with solar energy providing a main source of external energy to create stable climatic conditions

Solar Energy

energy from the sun, this isn't consistent across time and space; the movement of the Earth and relation to the Sun has driven climate change for hundreds of 1,000s of years

Volcanoes

Layers of dust/particles from volcanoes cover large areas of the globe, creating shade cover regions (due to the ground being unable to absorb solar energy) and cooler areas. Multiple eruptions can influence large regions and bring down average global temp.

Greenhouse Gases

- Refer to "greenhouse" buildings that capture heat for agriculture.
- Example: hot car after parking in sun. Due to solar radiation entering through windows, warming up interior, windows trapping heat that radiates off surfaces, and creating a total warming effect
- Gases include water vapor, carbon dioxide, and methane. Released by human practices, making things more severe

Positive and Negative Feedback Info

Pos. and Neg. feedback are reactions due to forcings changing subsystems and climate change. (e.g. forcing is climactic warming -> reaction is polar ice melting)

Positive Feedback

A reaction that occurs when the original forcing and feedback both push the climate in the same direction that it is headed (either warmer or colder)

Tipping point

the point where change cannot return to a former state due to positive feedback

Example of Positive Feedback

- Melting ice sheets at North Pole due to warming temp. in that region.
- Also, the melting warms up the climate; previously, ice reflects energy away from the surface, but now, more ocean water is exposed and absorbs solar energy. The warming of ocean is further increased.

Negative Feedback

a type of reaction that counteracts an initial change in climate, serving to moderate the climate change

Examples of Negative Feedback

- Occasionally, temp. rise in the Great Lakes during winter. This increases water in atmosphere, turning into clouds that cool the surface by blocking the Sun. Finally, the temperature cools as clouds bring snow that reflects away solar energy.
- Warming temp. in the ocean weaken the polar vortex, causing it to move south into the U.S. As a result, the polar vortex brings cold temperatures, making winter colder than typical for certain regions.
- In both examples, warming temperatures caused events that cooled down the temperature in certain regions.

Sources for Reconstructing the History of Climate

- Info. is needed to understand how climate and climate change works, as well as evidence of past events.
- Historians usually examine written sources in archives about past conditions, as well as nature itself.

archive

a physical repository of documents

Archives of Nature

a term scholars coined about places that climate scholars searched in nature to look for clues about climate's history

Archives of Society

a term scholars coined about places that held the written documents and sources that humans made about past climatic conditions

Archives of Nature II

include the traces of climactic impacts and conditions (water levels, plant growth, etc.) in nature, which itself is an archive of clues about climate's past.

Proxy

a natural feature that shows evidence of being impacted by specific climate conditions, giving an indication of climate in the past; tell of how climate was at a certain time in the past

Sources of Climate History

the three most revealing sources of climate history are ice, trees, and soil

Ice Core [Sampling]

a technique of drilling long cylinders of ice out of deep glaciers
- Snowfall from each year formed new, top layer that trapped atmospheric particles
- Ice Core from old glacier -> tells of atmospheric conditions hundreds of thousands of years ago

Trees

analyzed for information by counting the number of rings, then examining each ring for info about the weather during that year of the tree's life
- Example: can reveal if the year was dry, rainy, and the conditions of individual seasons

Dendrochronology

the practice of gathering climate information from tree rings; this word refers to trees and time

Sedimentation and Other Sources

the studying of sediment or mud on the bottom of lakes and ocean to find information about the historical composition and content of water, such as pollen

Sedimentation and Other Sources II

the sampling of coral in the ocean to find data similar to sedimentation studying and of past temperatures in the coral's location; as a result, scientists creatively harvest data to learn about the climate of the past and Earth

Archives of Society's Reliability

- Limited to what humans could describe: past hundreds or thousands of years vs. nature's millions of years.
- Most precise info. come from new developments. Oldest instrumental records from 1700 (thermometer's invention).
- Before that, humans left records, which are read by a system of proxies that provide decently reliable information.
- Ex: account of flood in 1500s does not tell rain amount but only a substantial amount of rain
- More specific in dating vs. nature. Nature can tell of a rainy year, but human records state the day/hour it rained.

Instrumental Records

refers to the measuring of precise and accurate information using scientific instruments to identify trends in the climate
- Limited: trends are precise yet go back for short period of time. Example: Phoenix's records show trends back to 1896.
- Analysis: measurement of temperature is at different layers of atmosphere; careful analysis is needed for precipitation to combine many points of data to understand trends over large areas, long timespans

Narrative Records

human-produced records that give clues about past climate conditions, such as the weather and other climate-related developments
- Treated as proxies for estimating info. that sci. instruments can record, such as temp., rainfall, or snowfall.
- Example: Records about cold winters, frozen rivers are compared with other records to gain a general climate trend
- Example: accounts of glacier expansion are not the same as temperature readings that show lowering temp., but are instead proxies to suggest that growth = declining temperature

Examples of Narrative Records

weather diaries/ship logbooks about conditions every day. Info about glacier growth/recession, lake/river water level, frozen state of a lake, or descriptions of occurrences like droughts or storms

Other Types of Records

markers of a highwater mark during a flood, works of art depicting weather conditions, grain prices (fruitful harvests = low prices); all give clues of past climate conditions

Warnings About Other Types of Records

paintings of weather conditions could be a real scene or inspired elsewhere; changing grain prices can also be from non-weather factors
- debating is a healthy part of scientific inquiry and leads to refined + reliable studying

Fields for Studying the History of Climate

different types of sources lead to different scholars being experts on specific types and having experise in researching climate history in a particular way
- The identification of sources, development of effective analysis for those sources, and increase of scholars joining that work may lead to a new scholarly field.

scholarly field

a group of scholars who share common practices for studying the type of evidence they analyze, a scholar is primarily a member on one scholarly field

Usage of Different Scholarly Fields

the combination of many robust fields with many scholars and research gives many perspectives on specific studies, fact checking on findings by a field, uses the strengths of different fields, and moves past the limitations of certain fields

Fields of Climate History

historical climatology, paleoclimatology, climate history, and the history of climate and society (HCS) offer complementary views of climate history to make a reliable picture of past climate & relationship to humans

Historical Climatology and Paleoclimatology

- Diff. names, essentially same field
- The two fields study climates of the past, usually before the 1800s when scientific instruments were used to create widespread & systematic records of climactic conditions

Climatology

a study of climate relying primarily on the archives of nature, with climatologists being adept at gathering info about climate from the natural world, like layers of ice/lake sediment/tree rings

paleo-

a prefix meaning ancient or old, conveying a similar idea to "historical"

Historical Climatologist Skills

collecting samples from nature (e.g. ice cores or tree samples), operating machinery/instruments for sample analysis, analyzing data to reconstruct past climate conditions, and communicating findings according to standard written conventions of climatology

Christian Pfister

a Swiss historian who was an influential pioneer in climate history, who compiled sources and created methodological (relating to methods in a certain study) approaches to analyze them. Proved that the archives of society can make trustworthy climate reconstructions.

Climate History

a study about collecting & studying sources from archives of society, analyzing based on historians' methods and conventions

Climate Historian Skills

the ability to read the language & script of texts; ability to find the texts, analytical techniques, & contextual knowledge to interpret texts accurately; the ability to formulate + communicate representations of history based on evidence

Climate Historians & Historical Climatologists

- Climate Historians look in the archives of society, but Historical Climatologists look in the archives of nature.
- Both look for info about past climate conditions.
- Scholars in one field may not be able to accurately analyze sources in the other field.
- However, the fields complement each other; they broadly explore same topic from different perspectives

The History of Climate and Society (HCS)

a new, emerging field, stemming from recent expansion of climate field (e.g. climate history)

HCS Goals

1. scrutinize + verify past claims via rigorous analyzing of evidence
2. emphasize the significance of precision in scale in making correct claims

Scale

The scope of one's investigation - geographic and chronological -

Geographic Scale

the scope of geographical areas (city, region, continent, globe, etc.)

Chronological Scale

the scope of time (days, decades, millennia, millions of years, etc.)

Conceptualizing Climate Change Today

- Many continuities + Discontinuities between Present and Past Climate Change history.
- Continuities (e.g., Earth subsystems) exist and help our understanding of climate change.
- Discontinuites (e.g., fossil fuel levels) can affect this understanding.

Quaternary Period

The present geological period from 2.588 million years ago that includes the Pleistocene, Holocene, and Anthropocene epochs

Holocene

the current epoch starting 11.7 thousand years ago, at the end of the last global ice age

Pleistocene

an epoch before the Holocene, starting 2.58 million years ago

Anthropocene

A proposed term used as the current epoch that emphasizes today's unique climate conditions, while putting climate change in a broader context

Concerns about Using the Term "Anthropocene"

scientists don't understand if present climate change is significant enough as the levels of transition of other epochs

Arguments for Using the Term "Anthropocene"

people already use the term Anthropocene, with overwhelming evidence with the start of climate shift in 1950; reaching the status of climate scale is difficult nonetheless

Climate Change and Narratives of Global History

- Climate incorporated into global history narratives starting in 2000 (when ideas of climate change starting converging)
- The revision of these stories is evident in our dynamic approaches to how climate applies to past and present.

Mapping Climate onto Existing Narratives

- Historical narratives already establish distinct, divisive political developments.
- Layering climate over existing narratives frequently causes correlations between social events and climate conditions (i.e., riots + drought).
Weaknesses: It creates a too-specific thesis prior to further study, makes constraints on climate history, and is basically a retelling of stories.

Climate Determinism and the Question of Causal Relationships

- Evidence is usually lacking to prove if one event leads to another, we need reasoning.
- Formerly believed that climate directly impacted course of human history. This is climate determinism.
- Recently, doubt placed climate's impact as a less important minor role. Led to causal mechanisms.

Climate determinism

an argument stating that climate sets the course of human history (i.e. good climate = thriving society), which is widely rejected today

casual mechanisms

an approach that asks what specifically did the climate impact that then became the exact thing that triggered a human response (i.e. a drought's reduced rain + wildfires)

Multiple Scales

- Human history's scale dates to 5-6 thousand years, from ancient civilizations, and up to 40k years. Earth's climate change history extends to millions.
- Different scales mean difficult comparisons. Anthropocene has brought the study of climate and human history; scientists are learning how to tell both stories properly.

Incongruent Chronological Scales

- Pre 20th cen. humans lacked impact + awareness on climate.
- Modern impact is on a small, quick scale on human history, yet substantial impact on climate history scale (millions of years).
- Due to this change, the two scales are incongruent, but intersected in our lifetime.

The Novelty of the Anthropocene

- New and old methods, narratives, and history must fuse.
- Change similar to the Anthropocene can help guide us out of global crises.
- Combining human + climate history is a new perspective.

The Holocene (Section II Introduction)

- An unprecedented period of humans thriving: 8 billion people, global manufacturing, a solo global force.
- The last Glacial Max. and Younger Dryas period occurred before the Holocene started 11.7k yrs. ago.
- An interglacial period part of a pattern in the Quaternary Period: ice receding and growing due to changing solar patterns
- Pattern states we should be cooling, but it's the opposite.

Last Glacial Maximum (LGM)

period from 20,000 years ago where much of Europe and North America was covered by ice, Asia with permafrost, and sea levels hundreds of feet lower than today's

LGM's Conclusion

ice melted, especially from major glacial meltwater from solar cycles 14k years ago, and caused strong changes defined as the Younger Dryas period

Younger Dryas period

a millennium period from 12,900 to 11,700 years ago, with cooler ocean temperatures and reversing of warming trends due to major ice melting

interglacial period

a warm period between ice ages

Milankovitch cycles

patterns in the Earth's orbit that affect the amount of solar energy the Earth absorbs at different times, strongly influencing periods of ice ages and interglacial

Three Periods of the Holocene (An Overview of the Holocene)

1. Early Holocene Subseries/Subepoch aka Greenlandian Stage/Age
2. Middle Holoscene Subseries/Subepoch aka Northgrippian Stage/Age
3. Late Holocene Subseries/Subepoch aka Meghalayan Stage/Age

Climate Change

a complex process of changes in the natural world

Earth System Science (ESS)

a new scientific approach that views the Earth's land, oceans, and atmosphere as a single system, looking at the interactions between air, water, land, and living organisms

Multidiciplinary approach

a method of studying which incorporates the findings of more than one academic discipline, giving a well-rounded picture of history

The Anthropocene

a new geological era in planetary and climate history where humans have become the driving force in planetary change, starting in 1950

Atmospheric Zones/Layers

exosphere, thermosphere, mesosphere, stratosphere, troposphere

exosphere

800 to 3000 km, 1200°C, the outermost layer of Earth's atmosphere, the layer of spaceships and satellites

Mesosphere

40-50 to 80-90 km, -2.5°C to -86.5°C, the middle layer of the atmosphere, the layer of meteors and meterological rockets

Stratosphere

11 to 50 km, -56.5°C to -2.5°C, the second-lowest level of the atmosphere, the layer of radiosondes

Troposphere

0 to 12-18 km, 15 to -56.5°C, the lowest level of the atmosphere, the layer of hot air balloons and passenger planes