Climate Variability and Change Flashcards

1
Q

What is the human-enhanced greenhouse effect?

A

The leading cause of global waring, atmospheric CO2 levels have increased by nearly double over the past 250 years. Methane, which is 25x more potent, has also increased by 150%.

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2
Q

What is paleoclimatology?

A

The study of past climate trends by using proxy measurementd to gauge climate changes.

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3
Q

What is dendrochronology

A

1 of the 6 climate proxies that scientists use to reconstruct past climates, it analyzes tree rings in order to establish dates for catastrophic events, such as drought, flood, fires, and major changes in temperature.

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4
Q

What is oxygen isotope analysis?

A

1 of the 6 climate proxies that scientists use to reconstruct past climates, it measures the amount of 16-O and 18-O in the atmosphere to determine existence of major climate changes.

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5
Q

What does an abundance of 16-O in oxygen isotope analysis tell us about the climate?

A

The abundance of this oxygen isotope tells us that there was homeostasis.

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6
Q

What does an abundance of 18-O in oxygen isotope analysis tell us about the climate?

A

An abundance of this oxygen isotope in oxygen isotope analysis tells us that there was an ice age because the other type of isotope became trapped in glaciers.

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7
Q

How do oceanic sediments affect oxygen isotope analysis?

A

Floraminafora calcium shells layer up and retain 16) levels during the period.

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8
Q

How do coral reefs affect oxygen isotope analysis?

A

Polyp exoskeletons retain 16-O levels of the time.

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9
Q

What is Ice Coring?

A

1 of the 6 climate proxies that scientists use to reconstruct past climates, it involves drilling into glaciers to reveal records of snow fall.

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10
Q

What do high 18-O levels in an ice core tell us about the climate conditions of the time?

A

An abundance of this oxygen isotope in ice cores indicates higher temperatures because more of these molecules evaporate and become snow.

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11
Q

Why do air pockets in an ice core help scientists make conclusions about the climate conditions of the time?

A

This feature of ice cores provides pure samples of 18-O and 16-O from the time.

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12
Q

What is palynology?

A

1 of the 6 climate proxies that scientists use to reconstruct past climates, it takes samples of pollen from sediment to determine the lifespan of plants.

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13
Q

What is radiocarbon dating in the context of palynology?

A

Provides age of organic plant material from up to 50k years ago by sampling relative amounts of two carbon isotopes, 14-C and 12-C.

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14
Q

What is a feature of 14-C in the context of palynology?

A

This carbon molecule decays at a known rate into 14-N, allowing scientists to estimate the age of a plant.

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15
Q

What is a feature of 12-C in the context of palynology?

A

The more stable of the two sample carbon isotopes during palynology, it more or less remains the same over time.

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16
Q

What are remnant glacial landforms?

A

1 of the 6 climate proxies that scientists use to reconstruct past climates, they leave distinct marks on landscapes by terrain abrasion.

17
Q

What does polished and striated bedrock tell us about climate conditions in the context of remnant glacial landforms?

A

This feature of remnant glacial landforms shows the height of a glacier.

18
Q

What are moraines in the context of remnant glacial landforms, and what does it tell us about climate conditions?

A

Unsorted glacial rock deposits, they accumulate at the edue of glaciers and proxy the original extent (width and length) og glaciers.

19
Q

What are speleothems?

A

1 of the 6 climate proxies that scientists use to reconstruct past climates,calcium carbonate in limestone and water drip in caves grow stalagmites and stalagtites with growth rings that provide geologic data to scientists.

20
Q

What are the causes, impacts and climate impacts of atmospheric aerosols?

A

Causes: natural: asteroids and volcanoes. Anthropogenic: pollution

Impact: natural causes spew particulate ash and aerosols into the stratosphere, where they absorb heat and lower temperature.

21
Q

What are the causes and climate impacts of fluctuations in solar output?

A

Cause type: natural