Chapter 16
Weather – daily changes in temperature, pressure, etc.
Climate – average weather conditions over a longer period of time
Earth heated by Sun –
(4 factors) influence climate greenhouse effect, latitude, wind patterns and
oceans & climate
Sun – radiation
Greenhouse gases – keep heat
close to Earth (H2O, CO2, O3, etc.)
heat reflected
back into space

Greenhouse effect – natural & necessary for life. However, we are putting
more CO2 into atmosphere so it traps more heat unnecessarily.
Humans are accelerating the process 
00latitude

Latitude – measurement of a place’s distance from the equator ( 00 latitude)
o The farther from the equator, the cooler the climate
o Unequal heating of Earth because radiation strikes Earth at different
angles – polar (less direct), temperate, tropical (most direct)
o Seasons change because as Earth orbits the sun, the angle at which
the sun’s rays strike parts of Earth changes
 Sunspot cycles –
 Sunspot = dark spot on surface of sun
 More sunspots = more energy emitted
 Sunspots cycle over approximately 11 years
 Wind Patterns
o Transport heat & moisture globally
o Global wind patterns are called prevailing winds
o Winds can carry H2O vapor long distances before it falls as
precipitation.
Wind & heat – regions by equator warm = air rises above them
North & South Pole cold = air moves downward
Warm air moves towards poles / cold air towards equator – moves in
large masses
Wind & Moisture – warm air carries more water vapor than cold air

Oceans & Climate
Oceans – transport heat and absorb CO2
Thermo(heat)haline(salt) circulation =
less dense, warmer H2O
Colder, saltier, more
Dense H2O
*water at poles sink and warmer H2O from equator moves to take its place
ex: Gulf Stream in the Atlantic Ocean
16.2
What evidence shows that global climate change is occurring, & why is it
happening?
Global Climate Change vs Global warming = many climate characteristics vs. increase
in Earth’s average temperature
Ways to study climate change –


Direct – measure conditions daily & can look at data to see modern* climate
change
Indirect – (proxy (substitute) indicators) to learn about ancient climates
o Ice cores – air bubbles trapped in ice & scientists remove long columns
of ice to study gas concentration in ancient atmosphere
o Sediment – samples of sediment beneath bodies of H2O usually find
pollen grains, remnants of plant vegetation
o Tree rings – analyze rings & chemical characteristics to infer climate
Evidence of climate change –



o Rising temperatures – global warming
Average atmospheric temperature near Earth’s surface up by 0.740 C
(330F) between 1906-2005
2005* hottest year to date
Changes in precipitation: (COMPLEX)
o Some places more precipitation than past ex: eastern North and
South America
o Some places less precipitation than past ex: SW United States &
Africa
o Heavy rains = floods
Melting Ice:
o Glacier National Park (150 glaciers down to 26)
o Glaciers shrink & disappear
o Reduction of snow/ice at poles
o Polar bears drowning
Rising Sea levels:
o As sea water becomes warmer, ice melts & volume increases
Models predicting future –

Climate models take data from atmosphere & oceans
o Models used on smaller scale in order to predict results on larger
scale
Cause of change –

Charles Keeling – hourly measurements of CO2 in atmosphere – in 1958 = 315
ppm ----- 2009 = 387 ppm caused by the Industrial Revolution which started
to put out more Greenhouse gases such as water vapor, N2O, CH4,(methane)
H2O, CO2
o motor vehicles = worst offender
o land = cutting trees & burning (trees take in CO2, loss of forests
contribute to an increase of CO2 in atmosphere
El Nino & La Nina –



interactions between ocean and atmosphere affect climate worldwide
El Nino = change in air pressure, wind, ocean temperature & circulation in
Pacific – winds weaken & H2O warmer than usual = causes rain storms &
floods in areas that are normally dry
La Nina = opposite El Nino
Carbon Dioxide –

Ocean holds 50x more CO2 than atmosphere. This has a cooling effect on
atmosphere. However, oceans absorb slower than CO2 is being added to
atmosphere by humans
Other factors –

Topography, volcanoes, regional vegetation, & changes in Earth’s orbit