Changes in Climate

present positions, polar zone, equator

200 mill years ago, most continents were far from their ___________________. Continents that are now in _______were once near the _________.

wide rings

________________ indicate a good growing season that was long or wet

short-term, amount of light given off by the sun

__________________ changes in climate have been linked to changes in the _______________________.

major volcanic eruptions, ash, aerosols, atmosphere

_____________________ can release huge quantities of _____ and ___________ into the ____________

narrow rings

________________indicate a dry year or a short growing season

ice core

a drill core of ice that can help tell the climates of the past

Little Ice Age

a period of cooling between 1600 and 1850 caused by a decrease in the sun's energy output

ice age

a period of glacial advance

forecast

a prediction about changes in upcoming weather

pangaea

about 200 million years ago, most of the land on earth was part of a single continent called ___________

solid, liquid, gas

aerosols are _________ particles or ________ drops in ____

glacial advance

an ice age is a period of ___________

upper atmosphere, months or years

ash and aerosols can stay in the __________ for ______________

interglacials

brief, warm periods that occur between long, cold ice ages

sunspots

dark, cooler regions on the surface of the sun

continental glaciers, large

during each ice age, huge sheets of ice called ________________ covered ______ parts of earth's surface

summer, layer of wood, under its bark, rings

each ______________, a tree grows a now ____________ just _________________. these layers form _________

pollen, lake bottoms, layers, samples, microscope, types of plants

each type of plant has a particular type of _____________. some _____________ has accumulated thick ___________ of mud and plant material over thousands of years. scientists can drill down into these and bring up __________ to examine. using a ____________ to look at the pollen in each layers, scientists can tell what _________________ lived there

warms

earth _______ when its orbit is more circular

elliptical orbit, sun

earth travels in an ____________ around the ____

circular

earth warms when its orbit is more __________

wet or dry, warm or cool

from thick and thin tree rings, scientists can se if previous years were ____________ and _____________

grooves, sediment, boulders, 20, two million

glaciers transformed the landscape: they carved ___________ in solid rock and deposited piles of ________, they moved huge _________ hundreds of km. From this evidence, scientists were able to conclude that there were about _____ major ice ages in the last _____________years

great

however slowly climate changes, the consequences can be ___________

continental glaciers

huge sheets of ice that covered large parts of earth's surface during each ice age

layer for each year, tree rings

ice cores have a _______________ just like __________

principle, today, conditions, past, conditions

in studying ancient climates, scientist follow an important __________: if plants and animals _______ need certain __________ to live, then similar plants and animals in the _________ also required those ___________

brief, warm, between, long, cold

interglacials are ______,________period that occur ___________ _____,_____ ice ages

slowly, years

long-term changes in climate happen more _________ and may not be apparent for _________

dry, short growing season

narrow rings indicate a _____ year or a __________________

movement of the continents, variations in the position of Earth relative to the sun, major volcanic eruptions, changes in the sun's energy output

possible explanation for major climate changes include ______________________, __________________________________, _________________, and _____________________________

similar conditions

scientists assume that the ancestors of these trees required ____________

Earth's climate record, in, pollen and dust

scientists study ice core layers to find out about ________________. They can also analyze what's __ the layers of ice, such as _______________

reflect, solar radiation, lower temperatures

scientists think that aerosols and ash ________ away some of the incoming ___________, and may _____________

aerosols

solid particles or liquid drops in gas

dark, cooler, surface

sunspots are ___,______ regions on the _____ of the sun

measure solar output, 400

sunspots can be used to ____________ over the past ____ years

shape, 100,000

the _____ of this ellipse varies over a period of about ____________ years

angle, axis tilts, direction

the _______ at which earth's ____________ and the ___________ of the axis change over time, affecting the severity of ice ages

11-year cycle, over hundreds of years

the amount of light given off by the sun changes over a regular _________ and can also change over _________________

severity of ice ages

the changes in earth's position affect the ____________________

Mount Tambora, 1815, 100, worldwide, cooler

the eruption of ____________ in Indonesia in ____ blasted about ___ cubic meters of ash into the atmosphere, which caused climates __________ to be dramatically ______ the next few years

10,000

the last ice age ended only about _________ years ago

cooling, 1600, 1850, decrease

the little ice age was a period of ______ between ____ and _____ caused by a _______ in the sun's energy output

land, sea, global patterns, wind, ocean currents, climates

the movements of continents over time changes the locations of _________ and ____, which affected the ______________ of ________ and _____________, which slowly changed ___________

sunspots, gives off more light

the number of _______ increases when the sun _________________

increases

the number of sunspots ___________ when the sun gives off more light

angle, axis, shape, orbit, climate

the__________ of earth's _____ and the _________ of its _______ affect its __________

100,00, ice ages, warm periods

these changes cause repeating _______ year cycles of ___________ interrupted by ___________

pollen, tree rings, ice cores

three ways scientists study information about ancient climates

ice cap, warm and moist, magnolias, palm trees, Florida

today Greenland is mostly covered by an _________. But 80 mill years ago it had a _______________ climate. Fossils of ____________ and _____________ found in Greenland provide evidence for this climate change. Today they are found in __________

more elliptical, less, ice age

when earth's orbit is ______________, ____ sunlight reaches earth during the year, causing earth to experience an _________

good growing season, long, wet

wide rings indicate a ______________ that was ______ or ____