16.1 Climate
Climate vs. Weather
Weather: daily changes in temperature, pressure, etc.
Climate: average weather conditions over a a longer period of time
Heating by sun (3 factors):
1. Greenhouse effect
The sun emits radiant energy and heats the Earth’s surface. Some of the heat is
radiated into space. Some of the heat is absorbed by green house gasses (H2O, CO2,
O3, etc.) and is trapped in the atmosphere
*Greenhouse effect is natural and necessary for life. However, we are putting more
CO2 into the atmosphere so it traps more heat unnecessarily.
2. Latitude
Measurement of a location’s distance from the equator (00 latitude)
-farther from equator, the cooler the climate
- unequal heating of Earth because radiation (polar, temperate, tropical) strikes Earth @
different angles
*seasons change because as Earth orbits the sun the angle at which the sun’s rays strike
parts of the Earth changes
Sunspot Cycles
-
sunspots = dark spots on the surface of the sun
- more sunspots – more energy emitted
-sunspots cycle over approximately 11 years
3. Wind Patterns – distribute heat and moisture globally
Wind and heat
- regions by the equator are warm = air rises above them
- North and South Pole are cold = air move downward
Warm air moves towards the poles/cold air towards equator  moves in large masses
Wind and Moisture - warm air carries more water vapor than cold air
4. Oceans and Climate
The ocean transports heat and absorbs CO2
Thermohaline circulation - colder saltier H2O is on the bottom of the ocean and the less
dense warmer H2O lies on top of it. These two continue to circulate creating Thermohaline
circulation
*water at the poles sinks and warmer H2O from Equator moves to take its place
ex. -Gulf Stream in the Atlantic
El Nino & La Nina: interactions between the ocean and the atmosphere, which affect the
climate worldwide
El Nino – change in air pressure, wind, ocean temperature, and ocean circulation in the
Pacific (the winds weaken and H2O is warmer than usual which causes rain storms and
floods in areas that are normally dry
La Nina – opposite of El Nino
Carbon Dioxide:
The ocean holds 50X more CO2 than the atmosphere. This has a cooling effect on the
atmosphere. However, oceans absorb CO2 at a slower rate than the amount of CO2 that is
being added to the atmosphere by humans.
Other Factors for Climate:
Topography, Volcanoes, Regional Vegetation, and changes in the Earth’s orbit
16.2 Climate Changes
Global Climate Change (GCC) vs. Global warming: GC = many climate characteristics vs.
an increase in Earth’s average temperature
Evidence of change:
1. Rising temperatures: average atmospheric temperature near Earth’s surface
increases by 0.740C between 1906 and 2005; 2005 is the warmest to date.
2. Changes in Precipitation: Complex
– some parts of the world are getting more precipitation (eastern N and S
America)
– less precipitation (Africa and southwestern US)
– heavy rain +floods
3. Melting Ice; (Glacier Nation al Park – 150 glaciers to 26)
Glaciers are shrinking and disappearing
Reducing snow and ice in North and South Pole
4. Rising Sea levels: as the seawater becomes warmer the volume increases
Ways to study climate change:
Direct – measure conditions daily and can look at data over time to see modern climate
change
Indirect – (Proxy (substitute) indicator) to learn about climates thousands/millions of
years ago
1. clues in ice – air bubbles trapped in ice and scientists remove long columns of ice to
study gas content in ancient atmosphere
2. sediment – samples of sediment beneath bodies of H2O  usually find pollen grains and
plants that grew in the past so we can infer climate
3. clues in tree rings – analyzing ring and chemical characteristics can tell about climate
conditions
Models Predicting Future:
- climate model: combine what is known about the atmosphere and oceans to
simulate the climate process
- test models by using past climate data
Cause of climate change:
Charles Keeling  hourly measured CO2 in the atmosphere (1958). He found 315 ppm in
1958 with an increase to 387 ppm in 2009.
 increase is due to greenhouse gases (CO2, N2O, CH4) increasing the greenhouse effect
 motor vehicles are the worst offender
 burning fossil fuels since the Industrial Revolution
 Land – use changes such as cutting of forests
16.3 Effects of Climate Change
Effects on the Ecosystem and Organisms
1. shifting habitats
2. change in migration times ex. robins
3. problems obtaining food ex. polar bear
4. effects of a changing ocean ex. coral food chain
- warmer H2O (coral bleaching)
- ocean acidity (shelled organisms are harmed)
Impact on People Now:
1. Agriculture and Forestry – droughts and changing season lengths have different
effects; dry season = forest fires and disease/insect outbreaks
2. Economic – extreme weather = damage = $ ex. Katrina, Super storm Sandy
People who work in agriculture and forestry suffer
3. Health Effects – sever heat waves increases = increase in heat stroke and death
Ex. – 2003 heat wave in Europe, which killed 35,000 people
Future impact on people
Computer modeling predicts an increase in CO2 levels and an increase in temperatures
*ranges of animals that transmit diseases may expand ex. ticks
* sea levels rise due to ice cap melting
*water supply  rising salt water may intrude on fresh water