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• Today’s Material:
• Thermal Energy
• Fossil Fuels
• Homework #2
Will thorium save us from climate change?
By David Suzuki with contributions from Ian Hanington, Senior Editor
• But many argue that, despite
Fukushima and other disasters,
nuclear is the best option to reduce
carbon emissions fast enough to
avoid catastrophic climate change.
• Because of problems with
radioactive waste, meltdown risks
and weapons proliferation, some
say we must develop safer nuclear
technologies.
• smaller modular reactors, reactors that shut down automatically after an accident
• Molten Salt Reactors (MSRs) are nuclear reactors that use a fluid fuel in the form of
very hot fluoride or chloride salt instead of the solid fuel used in most reactors.
• One idea is to use Thorium instead of uranium for reactor fuel. Thorium is more
abundant than uranium. Thorium-fuelled reactors produce less waste, and while
some trace elements in spent uranium fuels remain radioactive for many thousands of
years, levels in spent thorium fuels drop off much faster.
http://www.davidsuzuki.org/blogs/science-matters/2014/02/will-thorium-save-us-from-climate-change/
http://www.whatisnuclear.com/reactors/msr.html
The lasers fuelling hopes of unlimited,
clean nuclear energy
Scientists in California said
on Wednesday night that
they have for the first time
managed to release more
energy from their nuclear
fusion experiment than they
put into it, which marks a
critical threshold in
eventually achieving the goal
of a self-sustaining nuclearfusion reaction.
Nuclear fusion uses a fuel
source derived from water
and produces none of the
more dangerous and longlasting isotopes, such as
enriched uranium and
plutonium, that result from
conventional nuclear power
plants, which rely on the
fission or splitting of atoms
rather than their fusion.
http://www.independent.co.uk/news/science/the-lasers-fuellinghopes-of-unlimited-clean-nuclear-energy-9124237.html
http://chemwiki.ucdavis.edu/Physical_Chemistry/Nuclear_Chemistry/Fission_and_Fusion
http://obelkobusnel.wordpress.com/category/physics-grade-12-ib/
Fission
Fission is the splitting of a nucleus
that releases free neutrons and
lighter nuclei. The fission of heavy
elements is highly exothermic
which releases about 200 million
eV compared to burning coal which
only gives a few eV.
Fusion
Nuclear fusion is the joining of
two nuclei to form a heavier
nuclei. The reaction is followed
either by a release or absorption
of energy. Fusion of nuclei with
lower mass than iron releases
energy while fusion of nuclei
heavier than iron generally
absorbs energy.
http://www.daviddarling.info/images/binding_energy.jpg
Study: Arctic getting darker, making Earth warmer
http://phys.org/news/2014-02-arctic-darker-earth-warmer.html
The Arctic isn't nearly as bright and
white as it used to be because of
more ice melting in the ocean, and
that's turning out to be a global
problem, a new study says. With
more dark, open water in the
summer, less of the sun's heat is
reflected back into space. So the
entire Earth is absorbing more heat
than expected, according to a study published
Monday in the Proceedings of the National Academy
of Sciences. (AP Photo/NOAA)
http://www.pnas.org/content/early/2014/02/13/1318201111
“Observational
determination of albedo
decrease caused by
vanishing Arctic sea ice”
Kristina Pistone, Ian
Eisenman, and V.
Ramanathan
We find that this decline has caused 6.4 ± 0.9
W/m2 of radiative heating since 1979,
considerably larger than expectations from models
and recent less direct estimates. Averaged
globally, this albedo change is equivalent to 25%
of the direct forcing from CO2 during the past 30 y.
http://www.youtube.com/watch?v=HBbPBg3vj8&feature=youtu.be
The winter ice pack in the Arctic was once dominated by
old, thick ice. Today, very little old ice remains. This
animation shows maps of sea ice age from 1987 through
the end of October 2013. Age class 1 means "first-year
ice," which is ice that formed in the most recent winter.
The oldest ice (9+) is ice that is more than 9 years old.
Animation by NOAA climate.gov, based on research data
provided by Mark Tschudi, CCAR, University of Colorado.
Absorption of radiation by gases in
the atmosphere. The shaded area
represents the percent of radiation
absorbed by each gas. The strongest
absorbers of infrared radiation are
water vapor and carbon dioxide. The
bottom figure represents the
percent of radiation absorbed by all
of the atmospheric gases.
http://www.theguardian.com/theguardian/2008/mar/01/sci
enceofclimatechange.climatechange?CMP=fb_gu
James Lovelock: 'enjoy life while you can: in 20
years global warming will hit the fan'
• The climate science maverick believes
catastrophe is inevitable, carbon offsetting is a
joke and ethical living a scam. So what would
he do? By Decca Aitkenhead
The transfer of heat from the
hot end of the metal pin to
the cool end by molecular
contact is called conduction.
The rising of hot air and
the sinking of cool air
sets up a convective
circulation. Normally,
the vertical part of the
circulation is called
convection, whereas
the horizontal part is
called wind. Near the
surface the wind is
advecting smoke from
one region to another.
Sunlight that strikes a surface at an angle is spread over a larger area
than sunlight that strikes the surface directly. Oblique sun rays deliver
less energy (are less intense) to a surface than direct sun rays.
The average annual incoming solar radiation (yellow line) absorbed by
the earth and the atmosphere along with the average annual infrared
radiation (red line) emitted by the earth and the atmosphere.
http://www.youtube.com/watch?v=Ye45DGkqUkE
The
idealized
wind and
surfacepressure
distribution
over a
uniformly
watercovered
rotating
earth.
Water can exist in 3 phases, depending
upon pressure and temperature.
http://www.sci.uidaho.edu/scripter/geog100/l
ect/05-atmos-water-wx/ch5-part-2-waterphases.htm
http://chemwiki.ucdavis.edu/Physical_Che
mistry/Physical_Properties_of_Matter/Phas
e_Transitions/Phase_Diagrams_1
Latent Heat of Vaporization = 600 calories / 1g
Latent Heat of Condensation = 600 calories / 1g
Latent Heat of Fusion= 80 calories / 1g
How much energy to sublimate?
http://www2.chemistry.msu.edu/courses/cem152/snl_cem152_SS12/pracprob/practiceexam1.html
http://getsciencehelp.wordpress.com/category/uncategorized/page/4/
Class Review:
Energy
Energy transfer:
Radiation
Convection
Conduction
Next Class
Fossil Fuels
Factors that result from climate change and that can then amplify the causes of climate
change are known as “positive feedbacks.” Some of the key positive feedbacks include
thawing of permafrost (resulting in the release of previously trapped methane), forest
loss due to drought (resulting in the release of carbon sequestrated in the wood) and the
melting of the polar ice-caps (resulting in a reduced capacity to reflect solar energy from
the earth’s surface)
http://www.climate-leaders.org/climate-change-resources/climatechange/causes-of-climate-change
Figure 5.2
Energy, Environment, and Climate
Copyright © W.W. Norton &
Company 2012
Figure 5.9
Energy, Environment, and Climate
Copyright © W.W. Norton &
Company 2012
Figure 5.10
Energy, Environment, and Climate
Copyright © W.W. Norton &
Company 2012
Figure 5.11
Energy, Environment, and Climate
Copyright © W.W. Norton &
Company 2012
Figure 5.15
Energy, Environment, and Climate
Copyright © W.W. Norton &
Company 2012