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:▫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 scenarioswith 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:▫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

• 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- 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▫ 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:▫ 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:▫To protect human health▫To save money▫To improve our city/town▫To protect traditional activities▫To protect the environment