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Weaving Climate Change Concepts Into High School Science Teaching Weaving Climate Change Concepts Into High School Science Teaching PCCE Convention – Edmonton.

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Presentation on theme: "Weaving Climate Change Concepts Into High School Science Teaching Weaving Climate Change Concepts Into High School Science Teaching PCCE Convention – Edmonton."— Presentation transcript:

1 Weaving Climate Change Concepts Into High School Science Teaching Weaving Climate Change Concepts Into High School Science Teaching PCCE Convention – Edmonton October 16-17, 2012 Brian Martin – The King’s University College

2 Contexts for Good Science Teaching Good science teaching provides conceptual hooks that connect a student’s lived world with the world of scientific ideas Climate Change Science is a complex subject that reaches into virtually every part of the science curriculum – this is a natural and fruitful area in which to create these “hooks” Climate Change represents one of humanities greatest challenges and developing climate change literacy in students and the general population is a critical need

3 Five Sample “Lessons” Idea Concept(s)Suggested Curricular Links What is the mass of the atmosphere Force, Pressure, molScience 10 Phys 20 – Unit B Chem 20 – Unit B How does the burning of CO2 change the atmosphere? StoichiometryChem 20 – Unit D Acidification of the OceansSolutions, PHChem 30 – Unit D The Physics of Wind PowerConservation of Momentum and Energy, Power Chem 20 – Unit C Phys 30 – Unit A Photovoltaic EnergyEnergy and Power, dimensional arguments Science 10 Phys 20 – Unit C

4 (1) Mass of the Atmosphere What is the mass of a column of air 1m 2 at the base which exerts a force of 100 kN ? Ans: mg = 100 000 N m = 10 4 kg Every square m of the Earth’s surface supports 10 4 kg of air

5 How many molecules are there in the atmosphere?

6 (2) How Much CO 2 in ppm Does a Barrel of Oil Produce? 1 barrel releases 425 kg of CO 2; in moles this is Since the atmosphere contains 1.7 X 10 20 mol one barrel will release This is the fraction of CO 2 relative to the entire atmosphere – multiply by 1 million to get the parts-per-million or ppm. So, 1 barrel releases an additional

7 Is the observed increase in CO 2 “natural” or … Slope = 1.8 pm/a 46 ppm 25a

8 A Bit Closer to home… what is the annual Carbon footprint of the Alberta Oil Sands in ppm? …but – that’s not the end of the story!

9 Components of Fossil Fuel Emissions Le Quéré et al. 2009, Nature Geoscience

10 How about Coal-Generated Power? The Sundance plant produces roughly 17.5/40 times as much CO 2 as The Alberta Oil Sands In other words – Sundance adds (or about “half-a-Fort Mac”)

11 Let’s Re-run the Numbers… If the burning of oil accounts for only 36% of the total CO 2 loading then the total (anthropogenic) loading is … So – where is the rest going?

12 (3) Ocean Acidification The ocean buffers atmospheric CO 2 The ocean’s pH has dropped from 8.20 to about 8.05 since the industrial revolution

13  pH is only 0.15 – why Worry? At [8.20] H 3 O + concentration is 6.31 × 10 -9 mol L -1 At [8.05] H 3 O + concentration is 8.91 × 10 -9 mol L -1 This represents a 41% increase in hydronium ions – the ocean is being acidified

14 (4) The Physics of Wind Power How much power can a 100 m diameter windmill produce? Estimate the size of a wind farm capable of producing the power output of the Sundance thermoelectric plant (2100 MW)

15 Energy from the wind A packet of air of mass ‘m’ moving with velocity ‘v’ has energy given as Energy and power scale with the CUBE of wind velocity!

16 The total energy available is the difference between the energy of the incident air packet and the exiting air packet – Power that can be extracted is expressed as: Note the crucial role of the incident and exit wind velocity – we want to find the “sweet spot” – what is the maximum value for P effective ?

17 Force and Power on a Windmill A variation on Newton’s 2 nd Law Combine the two differently derived expressions for P

18 This is known as Betz’s Law (circa 1920) and leads to a remarkable result – the velocity across the rotor of the windmill is

19 Insert this into the power equation to get… Let x = v 1 /v 2 to get…

20 C p is the power coefficient for a wind turbine and the ratio 16/27 = 0.59 represents the maximum possible power that can be extracted. More typically wind turbines achieve 80% of this or 0.47

21 Example – Enercon 101 Wind Generator Optimal wind speed is around 10 m/s Cp = 0.47 so

22 How Many? To produce 2100 MW you will need… “Rule of thumb” – generator spacing is 7 times the diameter of the rotor or (0.1km)(7) = 0.7km Place in a grid 30 units X 30 units = 21 km X 21 km Cost? A 2008 figure commonly used is 1.3 million/MW so a 2100 MW wind farm would cost approximately $275 million From the TransAlta web site… “ A 53-megawatt uprate to Sundance 5 was completed in 2009 at a cost of $75 million.”

23 (5) Photovoltaic Energy By how much can I hope to reduce my annual CO 2 footprint if I install 12, 235 W solar panels on the roof of my house? How does the cost of electricity produced by a PV panel compare with current costs @12 c/kWh? kW = 1000 W is a power unit kWh = 1000 W × 3600 s = 3.6 MJ which is an energy unit

24 My Annual Electricity Use Total electrical energy consumption 2011 was 10 MWh Under bright sunlight each panel averages 140 W (averaged over the year) Edmonton receives on average 2300 h bright sunshine per year I can offset about 40% of my (electrical) CO 2 footprint

25 Cost of Solar Energy Total cash outlay for system = $15000 Warranty period = 25 years; estimated lifetime > 40 years Assume an average annual energy production of 3.6 MWh But the cost of sunlight won’t go up!

26 And there are a lot more… Compare CO 2 footprints of Methane and Coal Look at Isotopic Mass Ratios and Ice-cores Look at Carbonate-biCarbonate speciation Greenhouse gas heating through collisional de-excitation Declining sea ice and slope IR spectroscopy and spectral windows etc

27 Resources… www.kcvs.ca www.explainingclimatechange.ca Using Climate Change to Creat Rich Contexts for Physics and Chemistry Education. Brian Martin and Peter Mahaffy Using Climate Change to Creat Rich Contexts for Physics and Chemistry Education. Brian Martin and Peter Mahaffy

28 Thank You!


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