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Background
Information - Section III
Section I: The Arctic
Section II: Earth systems, Processes ang
Geoscience
Section III: Climate and Climate Change Research
Section IV: Other
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Background Section III: Climate and Climate Change Research
This background section explains three major concepts:
- What is climate?
- What is climate change?
- What is the greenhouse effect?
Climate and climate change terms
Weather is the condition of the atmosphere at any given place and time involving
factors such as temperature, precipitation, direction and speed of wind,
and the amount of water vapor in the air.
Climate is the long-term average of a region’s weather events from
season to season and year to year.
Climate Change represents a change in these long-term weather patterns.
They can become warmer or colder; annual amounts of rainfall or snowfall
can increase or decrease.
Global Warming refers to an average increase in the earth’s temperature,
which in turn causes changes in climate. Overall warming of the planet can
have very different regional affects. Warm wet weather might occur in one
location while cold and dry weather occur elsewhere. Evidence that global
warming is occurring include:
- a global mean surface temperature that has increased between 0.5 and
1.1 degrees Fahrenheit since the late 19th century;
- recent years have been among the warmest this century;
- melting of glaciers and polar sea ice;
- sea level rise;
- reports of Spring arriving earlier and Fall later in the Northern
Hemisphere.
Greenhouse Effect is a natural phenomenon. It works in the following way.
A warming results when atmospheric gases, like carbon dioxide or water vapor,
trap heat radiating from the earth and interrupt its course toward space.
“Greenhouse gases” trap heat in the atmosphere as the windows
on a greenhouse allow sunlight through but prevent the warm air from escaping.
Without this process the Earth would be a frigid planet. However, human
activities, such as burning fossil fuels to power our cars, homes and factories
release carbon dioxide and other greenhouse gases, are thereby intensifying
this natural occurrence.
Greenhouse Gases, particulate or aerosols occur both naturally (i.e. volcanic
dust or desert sand) and as a result of human activity and manufacturing
(i.e. fluorocarbons). When scientists refer to “greenhouses gases”,
they mean:
| carbon dioxide |
Released in the process of burning i.e. wood, fossil fuels and
absorbed by plants in the process of respiration. |
| water vapor |
Water molecules in the atmosphere as a result of evaporation. |
| methane |
Primary sources include bogs, swamps, rice fields, landfills, and
the guts of termites and cows. |
| nitrous oxide |
Found naturally in tropical soils and oceans and man-made in fertilizers.
|
| fluorocarbons |
Found in coolants and insulators in refrigerators and air conditioners. |
Questions to ask about climate and climate change
A. How do we study and predict global climate change?
-Scientific Research and Modeling
A model is a smaller representation of something larger and more complex.
Scientists use models to help study, understand and predict the natural
world. “The behavior of the climate system can be simulated with computer
models called general circulation models (GCMs). GCMs are computer representations
of global climate that are used to make climate change predictions.”
NOAA/NASA/EPA. What the Experts say about Climate Change.
For models to be useful and accurate tools they must be designed and developed
based on the most current and accurate scientific research and they must
be updated as new knowledge and understanding becomes available. For instance,
the Arctic plays a key role in global climate change. As scientists continue
to learn more about the processes and interactions in the Arctic they can
refine their models about how specific changes in the Arctic will affect
the global climate. The diagram illustrates some of the Arctic processes
that affect climate change, can you identify those processes?
The term “local knowledge” as used here refers to knowledge and
understanding that residents have about their community and region. That
knowledge is often in the form of traditional Native knowledge. “Contributions
of traditional knowledge have been well documented in several areas, including
biological information and ecological insights, resource management, protected
areas, biodiversity conservation, environmental assessment, social development
and environmental ethics…However, very little research has been done
to explore the value of traditional knowledge related to climate and climate
change research. We propose five areas of potential convergence to link
traditional knowledge with Western science.
- Local Scale Expertise – Understanding the impacts of global warming
for the local/regional area.
- Climate history and baseline data - …Traditional knowledge, through
cumulative experience and oral history, provides insights into past
climate variability and fluctuation; such knowledge is embedded in Inuit
history of wildlife populations, travels, unusual events, harvesting
records and migrations.
- Formulating research questions and hypotheses – Traditional knowledge
may expand the range of concepts and possibilities upon which to base
research questions and formulate hypotheses.
- Impacts and Adaptations: How Inuit see change – Human dimensions
of change, including planning and understanding human adaptation, is
an important aspect of climate change research but poorly understood
(IPCC 1995; Maxwell 1997; Smithers & Smit 1997). Including traditional
knowledge in adaptation research can establish the changes that the
communities see, how the perceive them, and how they explain these changes
in the context of livelihoods.
- Community-based environmental monitoring – Environmental monitoring
occurs in the context of seasonal rounds of resource harvesting activities;
it is closely tied to travel routes and the times and places of harvesting.
This kind of community-based monitoring ensures that ecological relationships
are noted…
These areas are a framework to facilitate the linkage of traditional
knowledge with Western science for collaborative climate change research.
Traditional knowledge represents another approach and perspective to
researching global climate change by comparing what is happening at
present to what has happened in the past.”
Text paraphrased from:
Riedlinger, Dyanna. (2000). Contributions of Traditional Knowledge to
Understanding Climate Change in the Canadian Arctic. University of Manitoba.B.
B. What are some of the technologies that we have available to assist in
our studies?
Models are improved through collection of scientific information about the
earth and its processes. There are a number of technologies that are available
as tools for scientific research about the earth’s climate (click here
for more information)
C. What is sea ice?
“Sea Ice is a thin, fragile, solid layer that forms in Polar Oceans.
It forms a boundary between relatively warm ocean and the cooler atmosphere.
There are many different kinds of sea ice.” http://southport.jpl.nasa.gov/polar/iceinfo.html
For more information about sea ice visit (http://www.arcticice.org/seaice.htm).
D. What does sea ice have to do with climate change?
Many things can be studied about sea ice that might give us insights to
climate change. Some things that scientists research about sea ice include
its type, motion, thickness, concentration, margins, albedo, etc. The ice
itself can also be analyzed for data.
Albedo Research
Sea ice, generally, reflects light and has a cooling effect on the planet.
Scientists study the reflective properties of sea ice or its albedo. (See
background section, “The Science if Light” to review the concepts
of reflection and absorption.) Even though the Arctic receives a large amount
of solar energy in summer, the high reflectivity (albedo) of snow and ice
surfaces keeps absorption of solar energy low. Therefore, the heat gained
during the long summer days is small and highly dependent on surface properties
such as topography and albedo. For instance, wet tundra and bare ground
(with low albedo) absorb more solar radiation than do high-albedo ice sheets.
Similarly, wet snow absorbs more radiation than dry snow.” The amount
of solar radiation absorbed or reflected impacts the global climate.
For more information about albedo go to: http://www.arcticice.org/earthalb.htm
This interaction between albedo and temperature is an example of a feedback
loop. “A feedback loop is a pattern of interacting processes where
a change in one variable, through interaction with other variables in the
system, either reinforces the original process (positive feedback) or suppresses
the process (negative feedback).” In the example described above and
as illustrated in the diagram, increased temperature, causes more ice melting,
which causes less reflection of solar radiation back to space, which in
turn causes more warming (a positive feedback).
Ice Core Research
Sea ice is also valuable in researching climate change because the ice holds
a historical record of the past climate and conditions. “Ice cores
drilled from the ice sheet provide a sample of all the layers of snow accumulated
over thousands of years, the oldest at the bottom. Once a site is selected,
a drill is set up and the coring begins. Mechanical drills can penetrate
up to 3 feet (1 m) at a time before being withdrawn for the core to be recovered.
To reach the 200-year depth, the team will have to drill 160-230 feet (50-70
m) which will typically take about a day.
Ice cores are usually about 3 inches (10 cm) in diameter. As they are brought
to the surface a scientist will examine the core and attempt to place that
section of core in time. Alternating bands of light and dark snow can been
seen when light is shone through the ice core from behind. The light layers
represent summer snow and the dark layers are winter snow. By keeping track
of the individual layers they can be counted in much the same way as tree
rings. More sophisticated techniques for dating ice cores are done later
back in the laboratory by analyzing the concentration of oxygen atoms in
the ice. Additionally, with the use of microscopy, observations about the
contents, structure and formation of the ice itself can provide researchers
with valuable clues about past conditions.
Climatic parameters such as air temperature, precipitation rate, and solar
radiation, among other things can be interpreted from ice cores. By studying
this record, scientists can identify the natural cycles in climate.”
E. What are some possible consequences of climate change?
Based on current climate models some projections are:
- Increasing temperature, “models predict 5-9 degrees Fahrenheit
(3-5 degrees Celsius) in the next 100 years”. US Global Change
research Program. (2001). Climate Change Impacts on the United States.
Cambridge University Press.
- Change in rainfall patters; likely increased precipitation in some
areas and draught in others; more severe or extreme weather events
- Sea level rise, bank destruction, stormsSea Ice, ice-sheets, permafrost
and glaciers melting; increased freshwater runoff/erosion into the oceans
- Possible change in atmospheric and ocean currents
- Continuing change in the chemical composition of the ocean and atmosphere
As a result of warming, the consequences for flora and fauna (including
humans) will vary depending on conditions and change occurring in a particular
location and the adaptability of the species in question.
- Climate change is projected to cause a change in distribution of ecosystems;
causing a shift or possible extinction for systems that are extreme
or susceptible to change.
- Plants are especially susceptible to changes in the environment because
of their sedentary nature.
- Ectotherms, cold-blooded animals which do not regulate their internal
temperatures, such as reptiles and amphibians are more affected by change.
- For specific effects climate change may have in the Arctic please
see the tables. (hydrology
tables.pdf )
Section I: The Arctic
Section II: Earth systems, Processes ang
Geoscience
Section III: Climate and Climate Change Research
Section IV: Other
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