Transcript Chapter 10 – Assessing and Responding to Climate Change

Chapter 10 – Assessing and
Responding to Climate Change
10.1 – Climate Models and Clean Energy
Uncertainties in Predicting Future Climate
• There are many variables that affect our climate
system:
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The carbon and water cycles
Concentrations of GHG’s in the atmosphere
Positive and negative feedback loops
The albedo effect
Ocean currents
• The problem for scientists is that there are too
many variable to study in order to accurately
predict how Earth’s climate will respond to
changes in GHG concentrations
• E.g. Arctic sea ice is melting faster than the
climate models predicted
• This means the Earth’s climate system might be
more sensitive to GHG emissions than
previously thought
• E.g. The rate at which the ocean and living
things are absorbing carbon is slower than
previously thought
• This means that the concentration of
atmospheric CO2 may increase faster than we
expect, even if emissions remain constant
Our Choice
• The main reason that scientists have difficulty in
predicting climate changes is because they
cannot predict what choices people make
• E.g. If we continue to use fossil fuels at the same
rate, we can expect our climate to change
drastically.
• However, if we switch to clean energy sources
that produce few or no greenhouse gases, Earth’s
climate may change less dramatically
Climate Projections
• A climate projection is a scientific estimate of future
climate conditions
• They are based on simulations by complete
computer models (climate models)
• These models consider future changes that will
affect GHG production
Developing Future Climate Models
• Scientists need to consider the following:
▫ How fast will the world’s population increase?
▫ What kinds of technologies will we be using in 10
years? 50 years? 100 years?
▫ What energy sources will we use in 10, 50 or 100
years?
▫ Scientists have developed
projections for many
scenarios
▫ Scenarios that show higher
GHG emissions (scenario A)
result in larger temperature
increases than scenarios
with lower emissions
▫ Under high emissions
scenarios, the temperature
changes by the end of the
century are double those
expected under a lower
emissions scenario
(scenario B)
Changing Our Energy Sources
Long-Term Effects
• Even if we stopped all use of fossil fuels today,
climate change would not stop entirely
• Earth would continue to warm over the next century
because of the GHG’s that have already been added
to the atmosphere
• If we don’t stop adding GHG’s, we are likely to see
severe consequences, including:
▫ The complete elimination of the Greenland and
Antarctic ice sheets – raise sea levels up to 15 m
▫ The extinction of up to half of the world’s species
▫ Increases in extreme weather events such as heat
waves, floods, and droughts
10.2 – Global Impacts of Climate Change
Expected Changes Due to Climate
• In order to evaluate the risks of human-caused
climate change, the Intergovernmental Panel on
Climate Change (IPCC) was formed
• To achieve this, several thousand scientists
voluntarily share and synthesize their work to come
up with current projected models for climate change
• There are some scientists, however, that disagree
with the IPCC reports, saying that they do not
capture the full severity of the impacts of climate
change
• Some scientists even suggest that most of the
impacts of climate change will be less severe than
predicted – and maybe even positive!!
Main Global Impacts of Climate Change
• The IPCC has identified four main global
impacts from climate change:
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Rising Sea Level
Impacts on Agriculture
Impacts on Ecosystems
Impacts on Human, Plant, and Animal Health
Rising Sea Level
• Glaciers and ice sheets melt and the oceans warm up and
expand, causing the sea level in the oceans to rise
• Low-lying coastal areas will be at increased risk of
flooding
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Climate change refugees
Abdul’s story
Impacts on Agriculture
• Dry regions, like Africa, may get even less
rainfall than they are currently experiencing
• Crops may be less productive, leading to
widespread famine
• Other areas, like the U.S. and Japan, could
experience more rainfall, and consequently,
flooding
• Warm and wet weather also leads to
damage from insects and other pests
Impacts on Ecosystems
• Some plants and animals are
likely to migrate towards the
poles as habitats become
unsuitable
• Biodiversity will be lost
• Changes in one population
could have repercussions
throughout the food web
Impacts on Human, Plant, and Animal Health
• Pests, diseases, and
disease carriers that
inhabit warmer
climates could spread
toward the poles
• This includes human
diseases, such as
malaria and dengue
fever (transmitted by
mosquitoes)
Continental Changes
Concern for the Canadian Arctic
• Climate change has been observed to be
happening more rapidly in the Arctic than
anywhere else in the world
• Sea ice is melting, causing habitats to change
▫ E.g. Polar bears cannot reach their food without
ice (ringed seals live on the ice)
▫ People who live in the Arctic and hunt for food will
be affected by changes in animal populations
Benefits of Arctic Climate Change?
• Less sea ice means it is easier for ships to reach
the Arctic and the valuable natural resources
that exist there
• Trees are beginning to grow in the Arctic,
helping to absorb CO2 from the atmosphere
• This may make it possible for farmers to grow
food at higher latitudes
• However, this can also reduce the albedo of the
tundra, resulting in a net increase in warming!
How Does This Affect the World?
• Albedo effect
▫ ocean and land will reflect less of the sun’s energy
• Release of CO2
▫ Permafrost may contain more stored CO2 and CH4, and if
released, will enhance the GH effect
• Sea level rise
• Ocean currents
▫ Fresh water flowing into the ocean from melting ice will slow or
stop ocean currents that transport thermal energy around the
globe
• Biodiversity
• Changes in shipping and transportation
Geoengineering (see pg. 418)
• Geoengineering is the use of technology to modify
Earth’s environment
1. Mirrors in Space
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Mirrors could be used to reflect some of the Sun’s radiation
back into space
This would take 55 000 mirrors, each 100 km2 in size!
2. Fertilizing the Oceans
- Adding fertilizers to the oceans enhances the growth
of algae, who would capture the CO2 in the
atmosphere and store it
3. Farming Algae
- Bags, vats, or tubes of algae can be used to absorb the CO2
produced by power plants and other factories
- The algae can then be processed into fuel
10.3 – Impacts of Climate Change on Ontario
Temperature and Precipitation
• Winters will become warmer, with fewer
extremely cold days and less snow
• Heating costs may go down, and there will be
less ice on the Great Lakes, leading to longer
shipping seasons
• However, there are likely to be more negative
than positive changes!
▫ E.g. More hot and humid summer days, leading to
heat waves and adverse health effects
• There will likely be more rainfall, but some areas
will be extremely dry, while others extremely wet
Changing Lake Levels
• The water levels in the Great Lakes are dropping
significantly – it is suspected that this is due to
climate change!
• Higher temperatures mean that there is less ice
cover, and more water evaporates
• Warmer lake waters will affect fish that live in
deep, cold water environments
• Algae will grow faster, and invasive species may
increase in numbers
Ecosystems
• Some tundra plants are flowering earlier and
reproducing faster
• Plants and animals from the U.S. could move further
north, causing a disruption for existing ecosystems
Disease and Illness
• Disease carrying organisms may increase as
average temperatures rise and precipitation
patterns change
• The risk of West Nile and Lyme disease
increases
• Worsening heat waves are likely to increase
heat-related illnesses and death
Agriculture
• Spring will come earlier, and the growing season
for crops and other plants would lengthen
• This sometimes encourages the growth of
unwanted plants
• Farmers may need to use more herbicides than
they do now
• Increases in smog will also damage crops
Forests
• Summers are expected to be warmer and drier,
causing more forest fires
• Insect populations will move north, attacking
the southern parts of the forest
• If the forest becomes unhealthy, it can become a
carbon source rather than a carbon sink
Electricity Use
• As summers get hotter, we
use more electricity for air
conditioning
• This requires more energy
to be generated from coal
or natural gas, producing
additional GHG’s
• Hydroelectricity will not be
available if water levels in
lakes drop significantly
10.4 – Taking Action to Limit Climate Change
How Quickly Do We Reduce GHG’s?
• Scientists suggest that we should limit the
overall temperature increase to 2°C in order to
avoid most of the dangerous impacts of climate
change
• It is suggested that we need to limit CO2 output
to no more than 450 ppm
• To do this by 2050, we would need to cut GHG
emissions by 80%
• Our provincial government has made this
commitment, but the federal government has
not!
The Canadian Government Perspective
• The Canadian government is working with many countries around
the world to reduce GHG emissions
• In 2002, Canada agreed to join the Kyoto Protocol, an international
treaty designed to set short term goals for limiting GHG’s
• Under this agreement, industrialized countries are required to
reduce their emissions by 2012
The Kyoto Protocol
• About 70% of people originally supported the Kyoto
Protocol, however, the government of Alberta was
specifically vocal about the thousands of jobs that
would be lost in the fossil fuel industry
• In 2006, our PM announced that we would not meet
our Kyoto targets by 2012
• The international community is now criticizing
Canada for not living up to our Kyoto commitments
• In June 2008, the opposition parties in the
Canadian government passed legislation (opposed
by the minority government) requiring Canada to
cut GH emissions by 80% by 2050
• New legislation has not yet been implemented
Provincial and Municipal Governments
and Climate Change
• The Ontario government introduced Go Green:
Ontario’s Action Plan on Climate Change in August 2007
• The action plan includes the following:
▫ Shutting down 4 remaining coal-fired generating stations
by 2014
▫ Reduce GHG emissions by 6% by 2014, 15% by 2020, and
80% by 2050
▫ More public transit
▫ Support green technologies
▫ Planting 50 million trees in southern Ontario by 2020
▫ Working with leading scientists to implement
recommendations for adapting to climate change
▫ Legislation to fast-track approval of renewable energy
projects like wind turbines
Businesses, Industries, and
Government – what can they do??
• Transportation
▫ Drive more fuel efficient cars (hybrid, electric)
▫ Use environmentally friendly fuels
• Producing energy
▫ Implement new technologies
▫ Clean energy like wind and solar
• Industries
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More efficient equipment will consume less energy
Recycle energy (capture thermal energy and use it to power other processes)
Impose taxes and limits on fossil fuel use
Capture and store carbon dioxide released by smokestacks
• Building and contracting
▫ Increase energy efficiency
▫ Install better insulation
▫ Rebates and tax incentives for insulating and energy efficiency
Businesses, Industries, and
Government – what can they do??
• Agriculture
▫ Restore polluted land so it can re-absorb carbon (ie. Plant native plants)
▫ Implement ways to reduce methane emissions in rice and cattle farming
▫ Use less nitrogen fertilizers
• Waste management
▫ Collect methane from landfills and use as an energy source
▫ Compost organic waste
▫ Reduce volume of waste generated & recycle
• Forests
▫ Plant more trees to replace trees that are cut down
▫ Reduce deforestation
▫ Produce and use fuels from waste forestry products (biofuel) instead of
fossil fuels
10.5 – What Can Individuals Do?
Reducing Your Emissions
• More than 1/3 of Canada’s greenhouse gas
emissions come from the activities of individuals
• Most of the greenhouse gas emissions come from
transportation and home heating/cooling
• There are many things you can do to reduce
emissions, including:
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Walk, bike, take public transit, carpool
Choose fuel efficient cars
Turn off lights and unplug unused appliances
Take less airplane flights
Use air conditioners only when necessary
Plant trees native to your area
Turn off running water
And more!!!!
Carbon Offset Credits
• Environmentalists suggest that it is impossible to
reduce our GHG emissions to zero
• However, we can achieve “carbon neutrality” by
purchasing carbon offset credits
• By purchasing credits in clean energy programs like
wind farms and solar power, we reduce the burning
of fossil fuels, and therefore offset CO2 emissions
• There is some criticism of this program:
▫ They suggest we are easing the conscience of rich
countries and allows them to continue their current
lifestyle of using fossil fuels
Climate Change and Stewardship
• Stewardship means the careful management of
something that one does not own
• We now understand that the Earth does not belong
to us; we are simply its caretakers!
• Ultimately, the value we place on our planet
identifies our responsibility to care for it in the long
term
• Some reasons why we should be stewards of the
Earth include:
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To protect human health
To save money
To improve our city/town
To protect traditional activities
To protect the environment