Download Climate and Climate Change

Weather, climate and climate change
lecture before group exercise
Ch. 20, sections 20.1, 20.4. Review
sections 18.2 and fig. 18.7
What is weather?
• State of the atmosphere at any given
time
• Weather is: temperature, humidity, type
and amount of cloudiness, air pressure,
speed and direction of wind
Climate and Climate Change
• Climate: aggregate weather conditions;
“weather over 30 years”
• NOT an average – must take into
account variability and extreme events.
• Sun powers it all.
Climate is an aggregate of weather
• Involves the exchanges of energy and
moisture that occur among the
•
•
•
•
•
Atmosphere
Hydrosphere
Solid Earth
Biosphere, and
Cryosphere (ice and snow)
Global climate zones
• Climate and biology (biome) complexly
intertwined
• Figure 20.8 Global climate zones. Each
climate zone supports a unique biome.
• Figure 20.9 A model climograph. This
graph shows the average monthly
temperature (curved line) and average
monthly precipitation for Nashville, TN
Fig. 20-8a, p.488
Fig. 20-8b, p.489
Fig. 20-9, p.490
Fig. 20-10, p.491
Fig. 20-11, p.491
Fig. 20-12, p.492
Climate change: It’s more than average
temperature….
What if just winters were warmer?
What if winters were the same, summers
much hotter?
What if precipitation greatly increased, or
decreased?
What if most precipitation fell at one time
of year, say in the winter and spring?
• All of these
changes would
affect living
things
• Esp. crops
grown for food,
and humans
What’s heating the atmosphere?
• Starts with: solar radiation
• Atmosphere lets most light in (fig. 18.6)
• Some reflected, some absorbed by ground
Greenhouse effect (Fig. 18.7)
1: Earth’s surface
absorbs shortwavelength solar
radiation (orange
lines), and become
warmer
• 2: Earth’s surface reradiates the energy
as long-wavelength
infrared heat rays
The Greenhouse Effect
• Step 3:
Molecules in the
atmosphere
absorb some of
the heat, and
the atmosphere
becomes
warmer.
• CO2, water,
others
CO2, Greenhouse Effect,
Global Warming
• Today: CO2 concentration in our
atmosphere is >0.037 % or 370 PPM
• If less CO2: cooler temperatures and
cooler climate
• If more CO2: warmer temperatures and
warmer climate
• Industrial Revolution was powered by
burning coal and fossil fuels
• Continues today with burning petroleum (fig.
5.30A: energy use in USA, 2000)
Oil and gas
• Oil and gas are hydrocarbons: chains or
rings of C and H
• React with O2 to form gas and heat energy
• For example, octane:
• 2 C8H18 + 25 O2 = 16 CO2 + 18 H2O +
heat energy
• Example: propane:
• C3H8 + 5 O2 = 3 CO2 + 4 H2O + heat energy
(Slide from February!)
Most up-to-date info
Fig. 21-4, p.503
Pretty clear now:
• There has been an increase in average
temperature by 0.3 to 0.6 °C
• Question: “Are these temperature trends
caused by human activities or would they
have occurred anyway?”
• Given the consequences, can we afford to
do nothing?
Local climate change?
• Study local records and plot changes
• Keep in mind weather is very variable!
• Local area with best long-term records:
Greenville Water plant, Darke Co., OH
• Records start in 1887
• Source of graph on next slide:
http://cdiac.esd.ornl.gov/cgibin/broker?_PROGRAM=prog.climsite.sas
&_SERVICE=default&id=333375
Ave. Temp., 1900 - 2002
Is climate change happening here?
• And if not, do we really need to worry?
• Are there other places that show climate
changes a bit more clearly?
• And if not, what is the big deal?
Fig. 21-16, p.515
Climate ‘hotspots’
• Areas in the far north and far south are
warming up faster than mid-latitudes
• Spring starting early
• Permafrost melting or partially melting
• Southern species spreading northward
Climate ‘hotspots’
• Prep for Friday’s
exercise:
• Hay River, NWT, on
Great Slave Lake,
near Yellowknife.
• Long, nearly
complete record of
temp and
precipitation
Vegetation type: Northern
evergreen forest
In area of
sporadic
permafrost
Ohio Academic Science Standards
K-2 Science benchmarks
• Gather & communicate information from
careful observations and simple
investigation. (Scientific Inquiry)
• Observe, describe and measure changes
in the weather, both long term and short
term (Earth & Space Science)
Ohio Academic Science Standards
3 – 5 Science benchmarks
• Analyze weather and changes that occur over a
period of time (Earth & Space Science)
• Organize and evaluate observations,
measurements, and other data to formulate
inferences and conclusions. (Scientific Inquiry)
• Use results and data from investigations to
provide the evidence to support explanations
and conclusions.
(Scientific Inquiry)
Ohio Academic Science Standards
3 – 5 Science benchmarks
• Distinguish between fact and opinion and
explain how ideas and conclusions change
as new knowledge is gained. (Scientific
Ways of Knowing)
• Explain the importance of keeping records
of observations and investigations that are
accurate and understandable. (Scientific
Ways of Knowing)
Ohio Academic Science Standards
6 - 8 Science Benchmarks
• Describe interactions of matter and energy
throughout the lithosphere, hydrosphere &
atmosphere (e.g. water cycle, weather,
etc.)
Ohio Academic Science Standards
6 - 8 Science Benchmarks
• Analyze and interpret data from scientific
investigations using appropriate
mathematical skills in order to draw valid
conclusions. (Scientific Inquiry)
• Use skills of scientific inquiry processes.
(e.g. hypothesis, record keeping,
description and explanation)
(Scientific Ways of Knowing)
Ohio Academic Science Standards
9 - 10 Science Benchmarks
• Explain that many processes occur in
patterns within the Earth’s systems. (Earth
& Space Science)
• Summarize the historical development of
scientific theories and ideas, and describe
emerging issues in the study of Earth and
space sciences. (Earth & Space Science)
Ohio Academic Science Standards
9 - 10 Science Benchmarks
• Explain that scientific knowledge must be
based on evidence, be predictive, logical,
subject to modification and limited to the
natural world.
(Scientific Ways of Knowing)
• Explain how scientific inquiry is guided by
knowledge, observation, ideas, and
questions. (Scientific Ways of Knowing)
Ohio Academic Science Standards
11 -12 Science Benchmarks
• Describe how Earth is made up of a series of
interconnected systems and how a change in one
system affects other systems. (E&SS)
• Explain that humans are an integral part of the
Earth’s system and the choices humans make today
impact natural systems in the future. (E&SS)
• Summarize the historical development of scientific
theories and ideas, and describe emerging issues in
the study of Earth and space sciences. (E&SS)
Ohio Academic Science Standards
11 -12 Science Benchmarks
• Predict how human choices today will
determine the quality and quantity of life
on Earth. (Science & Technology)
• Explain how scientific evidence is used to
develop and revise scientific predictions,
ideas, or theories. (Scientific Ways of
Knowing)