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Climate Change
• http://www.youtube.com/watch?v=V1VYmpTikgw&feature=related
Temperature trends• We’ve seen a lot of record-breaking temperatures in the
past decade. The average temperature across the world has risen by 0.76°C since 1880 (when detailed temperature data was first recorded).
Leading causes
• Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions.
• CO2 – this is a by-product of fossil fuel combustion (oil, natural gas and coal).
• CH4 – produced mostly by livestock (during digestion) and by manure management.
• N2O – produced from industrial activity and fertilizer use.
How it works• Greenhouse effect
• http://videos.howstuffworks.com/howstuffworks/2261-how-greenhouse-gases-work-video.htm
Greenhouse gas emissions per industrialized country
The Future• According to predictions, average earth temperatures could rise by 3°C to
5°C by 2100.• This could have disastrous meteorological, geographical, and biological
effects.
Impact of climate change• Melting ice in the north:• We have an enormous amount of water trapped in the form of
ice in the polar ice caps.• Melting the ice caps could raise the sea level by several feet.• Florida would be submerged.
Impact of climate change• The threat of malaria:• Malaria is a parasite transmitted by mosquitoes. It infects
humans and destroys our liver. • The parasite can only tolerate specific temperatures. With
increasing temperatures across the world, the parasite could spread.
Impact of climate change• Drought-stricken farms:• Higher temperatures lead to higher rates of evaporation.• Less water for farmers growing our foods.
Global solution• United Nations Framework Convention on Climate Change (1992, Brazil)
154 countries and the EU decided they needed to take action.• Five years later during their 3rd meeting, taken place in Kyoto , Japan, they
signed the Kyoto Protocol.• The countries agreed to lower their greenhouse gas emissions to levels 5%
below their 1990 levels. These levels were to be measured in about 10-15 years (2012).
• Canada’s emissions are still on the rise.
Review• What’s the average global increase in temperature since
1880?• What are the three leading causes of the greenhouse effect?• Concerning the impact of climate change, what were the three
repercussions discussed?
• An agreement was signed by several countries pledging a decrease in greenhouse gas emissions. What was the agreement called?
Drinking Water• We need 1.5L/day to live. Just 4 days without water and we
die. It’s very important.
• Despite covering 2/3 of the world’s surface, only 2.5% of this water is fit for human consumption. The rest is too salty.• Unfortunately, most of this 2.5% is inaccessible: trapped in
glaciers and underground aquifers.
Water quality• There are several criteria which are examined in order to ensure the
quality of our drinking water:1. Sensory properties: colour, clarity, odour, taste.2. Physical and chemical properties: pH and salinity.3. Toxic substances: heavy metals, pesticides.4. Microbiological parameters: bacteria, viruses, fungi.
Unfortunately, every year contaminated water claims five million lives.
Threats to the water supply• Pollution: most common pollutants include: 1. pesticides and fertilizers used on farmlands2. heavy metals discharged from in wastewater from factories3. bacteria from sewage water.
• Climate change itself: rising temperatures cause increasing evaporation.• This could lower the level of the St. Lawrence. Water from the Gulf would
come in increasing the salinity of the water, making it unfit for consumption.
Excessive human consumption• In homes, individual Canadians use an average of 335L of water per day.• This is an average over the year: includes filling swimming pools, car
washes, and lawn watering.
Smart homes• http://news.discovery.com/videos/tech-smart-tech-measures-
personal-water-consumption.html
Review questions• What are the criterion used verify the quality of our water?
• What percent of the world’s water is drinkable?
• What are some of the threats to our water supply?
Deforestation• Forests are important for a variety of reasons.1. They’re home to a large proportion of plants and animals.2. They capture carbon dioxide.3. Prevent soil erosion (loss of soil due to floods or wind).4. Reduce risks of natural disasters (floods, avalanches, and desertification).
Net change in forest area, 2005-2010 (ha/year)
Causes of receding forests
1. Clearing land for farming.• In some areas, forests are cleared by fire and crops are planted
until the soil is no longer fertile.2. Logging.• Harvesting forests for the pulp-and-paper or lumber industries.
3. Monoculture.• A practice which involves planting one type of crop or species of
tree. These are more vulnerable to disease and insects because of reduced biodiversity.
• Also causes soil depletion as the monocultures draws constantly on the same nutrients.
Causes of receding forests4. Urbanization.• As populations grow, the need for more space will increase.5. Air pollution.• Fossil fuel combustion releases pollutants into the air.• Sulphur dioxide (SO2) and nitrogen oxides (NOx) contribute to ACID
RAIN.• Soil exposed to acid rain cannot retain its nutrients.6. Natural factors.• Fires, landslides, or diseases caused by insects.
Impact of deforestation• On biodiversity:• Forests harbour ~70% of living species, including birds, insects,
plants, fungi and microorganisms.• On the water cycle:• Trees reduce surface runoff, as they absorb much water.• Trees reduce soil erosion.• Trees release water into the air through evapotranspiration
(maintains air humidity).• On the climate:• When cut, the carbon in the trees is released as CO2 as the trees
decompose. This is responsible for much greenhouse gas emission.• By acting as windbreaks and maintaining air humidity, trees help
regulate temperatures in certain areas (think of drier areas like deserts).
Deforestion• http://
www.guardian.co.uk/environment/video/2010/sep/28/deforestation-paraguay
• In Barbados: http://www.youtube.com/watch?v=AOjRnqRSCO8
Main stages of the water cycle
1. Evaporation2. Condensation3. Water storage in the atmosphere4. Precipitation5. And repeat…
Water cycle
We can damage certain parts of the water cycle…• Hotter weather more evaporation but less condensation.• Clearing trees less humidity and less evapotranspiration.• Less plants and trees less water absorbed from the soil, more
remains trapped in the earth.
Review questions…• Why are forests so important?• What is causing them to recede?
• Is the loss of forest a bad thing? And why?
Effect of greenhouse gases• Warming climate: sunlight going through the atmosphere heats up the
earth’s surface. The greenhouse gases in the atmosphere prevent the heat from being lost. Analogy: the interior of a car on a sunny day.
• Also, we get the depletion our ozone layer because of halocarbon compounds we use as refrigerants: CFCs, freon, etc.
• The ozone layer is a layer of O3 that protects us from the electromagnetic radiation of the sun.
Energy• Consumption:• North Americans have a very unhealthy appetite for luxury items
requiring enormous amounts of energy to make, i.e. the automobile.• The automobile has helped urbanization become a reality because
people can live farther from where they work.
Classical sources of energy• Problems with these energy sources: greenhouse gases are emitted
and they’re not renewable.
• Sources:1. Wood: in some parts of the world, people use wood for cooking and
heating purposes.• This can lead to desertification due to deforestation.
2. Coal: This was a popular means of producing electricity in Canada up until the 20th century.• Burning coal releases SO2 and NOx causing acid rain.• Also, produces mercury emissions which returns to earth in the rain. This
is absorbed by fish, which are consumed by humans.
Classical sources of energy
3. Oil: this is unearthed from deep wells in the earth. Oil is refined into all sorts of products, like gasoline.• Burning oil also generates gases responsible for acid rain.• Its combustion isn’t the only process that is harmful: it’s
extraction from tar sands and transportation are also very polluting.
Classical sources of energy4. Natural gas: these are combustible gases which burn cleaner than oil or coal. Mainly composed of methane (CH4). We also find ethane (C2H6) as well.• We use it to heat homes and generate electricity.
5. Nuclear: When a uranium atom breaks apart, it releases a lot of energy in the form of heat. This spins turbines to generate electricity.• No greenhouse gas emissions, but you’re left with nuclear waste.
Renewable energy1. Hydroelectricity using water from rivers to spin turbines.2. Wind power largest ones can generate enough power to supply
200-300 homes with electricity.3. Solar energy photovoltaic (solar) panels generate a current when
they’re hit with sunlight.4. Geothermal energy capturing heat from inside the earth to
generate electricity.5. Tidal power using the movement of water in tides to spin
turbines.
Reducing consumption• Minor changes: turning off lights or heating and using energy-
efficient light bulbs.
• Major changes: 1. Energy-efficient cars2. Energy-efficient industries (released water vapour can heat
building in winter)3. Energy-efficient homes
Renewable energy• http://www.youtube.com/watch?v=NQKafeKMJIQ
Review• So what types of classical energy sources exist?
• What types of renewable energy sources exist?
• Are there common problems between the two?
• Ultimately, what can we do to reduce our carbon footprint?
Food production• In order to keep up with the high food demand, we’ve had to
revolutionize our agricultural practices.• This includes the use of machinery in growing and collecting
food.• The main idea is mass production.
Problems with mass production
• Soil compaction: heavy machinery compacts the earth. This reduces arable land because the land doesn’t absorb water as easily.
• Soil depletion: intense farming doesn’t give soil time to renew its supply of nutrients.
• Fertilizers: chemicals can runoff into water supply.
• Pesticides: can be very harmful to humans over time.
Global food crisis• Rising food prices all over the world:• http://www.youtube.com/watch?v=3qzKUZ-FUUw&feature=re
lated
GMO• Genetically-modified foods.
