Presentation on theme: "Using visualiztions of the science of climate change to change the climate of Science Teaching Using visualiztions of the science of climate change to."— Presentation transcript:
Using visualiztions of the science of climate change to change the climate of Science Teaching Using visualiztions of the science of climate change to change the climate of Science Teaching CCTCA – February 2014 Brian Martin The Kings Centre for Visualization in Science The Kings University College
Contexts for Good Science Teaching Good science teaching provides conceptual hooks that connect a students 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
Digital Resources at The Kings Centre for Visualization in Science vc3chem.ca
Sample Lessons IdeaConcept(s)Suggested Curricular Links What is the thickness and mass of the atmosphere Force, Pressure, mol, Back-of-the – envelope or Fermi questions Science 10 Phys 20 – Unit B Chem 20 – Unit B How does the burning of CO 2 change the atmosphere? StoichiometryChem 20 – Unit D When will the summer polar-cap disappear? Slope, equation of lineScience 10. Unit B, D Physics 20 – Unit A How do greenhouse gases work?Light and Matter Interaction, Blackbody radiation, quantum Phys 30 – Unit C,D Acidification of the OceansSolutions, PHChem 30 – Unit D The Physics of Wind PowerMitigation, Conservation of Momentum and Energy, Power Chem 20 – Unit C Phys 30 – Unit A Photovoltaic EnergyMitigation, Energy and Power, dimensional arguments Science 10 Phys 20 – Unit C
(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 = N m = 10 4 kg Every square m of the Earths surface supports 10 4 kg of air
How many molecules are there in the atmosphere?
(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 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
Is the observed increase in CO 2 natural or … Slope = 1.8 pm/a 46 ppm 25a
A Bit Closer to home… what is the annual Carbon footprint of the Alberta Oil Sands in ppm? …but – thats not the end of the story!
Components of Fossil Fuel Emissions Le Quéré et al. 2009, Nature Geoscience
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)
Lets 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?
The Melting Polar Cap If current trends continue when will September Polar Sea-ice disappear?
YearArea (Mkm 2 )
How Do Greenhouse Gases Work?
(3) Ocean Acidification The ocean buffers atmospheric CO 2 The oceans pH has dropped from 8.20 to about 8.05 since the industrial revolution
pH is only 0.15 – why Worry? At [8.20] H 3 O + concentration is 6.31 × mol L -1 At [8.05] H 3 O + concentration is 8.91 × mol L -1 This represents a 41% increase in hydronium ions – the ocean is being acidified
(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)
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!
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 ?
Force and Power on a Windmill A variation on Newtons 2 nd Law Combine the two differently derived expressions for P
This is known as Betzs Law (circa 1920) and leads to a remarkable result – the velocity across the rotor of the windmill is
Insert this into the power equation to get… Let x = v 1 /v 2 to get…
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
Example – Enercon 101 Wind Generator Optimal wind speed is around 10 m/s Cp = 0.47 so
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.
(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 c/kWh? kW = 1000 W is a power unit kWh = 1000 W × 3600 s = 3.6 MJ which is an energy unit
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
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 wont go up!
And there are a lot more… Compare CO 2 footprints of Methane and Coal Look at Isotopic Mass Ratios and Ice-cores Nuclear energy (conventional, fast breeder, Thorium) Bio-fuels Look at Carbonate-biCarbonate speciation Greenhouse gas heating through collisional de-excitation Declining sea ice and slope IR spectroscopy and spectral windows etc
Resources… 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