Transcript GK12 Module 2 - UCSF Biochemistry & Biophysics

Balloon Or Bust
Exploring Climate Change and
Greenhouse Gas
You’ve heard a lot about climate change:
- It’s changing weather patterns
- The ice caps are melting
- Seasons are becoming more extreme
- The sea level is rising
But what causes that? Is it true?
The Greenhouse Effect
Why is it called the Greenhouse Effect?
http://www.natureeducation.org/greenhouse-gas.html
What do the Mythbusters say about
it?
http://www.youtube.com/watch?v=pPRd5GT0v0I
What are greenhouse gases?
- CO2 accounts for 77%
of greenhouse gases
- 57% of that CO2
comes from man
made sources,
especially energy
generation
- There are natural
sources of greenhouse
gasses (e.g. volcanos
erupting)
- Water is also
considered a
greenhouse gas (not
pictured here)
www.epa.gov
How do Greenhouse Gases get into
the environment?
http://www.epa.gov/climatechange/ghgemissi
ons/global.html
Is it getting better?
• The amount of CO2 in the atmosphere is actually
increasing!
http://www.epa.gov/climatechange/ghgemissi
ons/global.html
Correlation to world population
growth:
Who’s responsible for Greenhouse Gas
Emissions?
http://www.epa.gov/climatechange/images/gh
gemissions/GlobalGHGEmissionsByCountry.pn
g
How are Greenhouse Gasses affecting
the environment
Funny… looks like another graph I saw…
http://data.giss.nasa.gov/gistemp/2002/
So what’s happening to
the environment?
• Ice is melting worldwide, especially at the Earth’s poles. This
includes mountain glaciers, ice sheets covering West Antarctica and
Greenland, and Arctic sea ice.
• Researcher Bill Fraser has tracked the decline of the Adélie
penguins on Antarctica, where their numbers have fallen from
32,000 breeding pairs to 11,000 in 30 years.
• Sea level rise became faster over the last century.
• Some butterflies, foxes, and alpine plants have moved farther north
or to higher, cooler areas.
• Precipitation (rain and snowfall) has increased across the globe, on
average.
• Spruce bark beetles have boomed in Alaska thanks to 20 years of
warm summers. The insects have chewed up 4 million acres of
spruce trees.
http://environment.nationalgeographic.com/e
nvironment/global-warming/gw-effects/
What will happen if we let it continue?
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Sea levels are expected to rise between 7 and 23 inches (18 and 59 centimeters)
by the end of the century, and continued melting at the poles could add between
4 and 8 inches (10 to 20 centimeters).
Hurricanes and other storms are likely to become stronger.
Species that depend on one another may become out of sync. For example, plants
could bloom earlier than their pollinating insects become active.
Floods and droughts will become more common. Rainfall in Ethiopia, where
droughts are already common, could decline by 10 percent over the next 50 years.
Less fresh water will be available. If the Quelccaya ice cap in Peru continues to
melt at its current rate, it will be gone by 2100, leaving thousands of people who
rely on it for drinking water and electricity without a source of either.
Some diseases will spread, such as malaria carried by mosquitoes.
Ecosystems will change—some species will move farther north or become more
successful; others won’t be able to move and could become extinct. Wildlife
research scientist Martyn Obbard has found that since the mid-1980s, with less ice
on which to live and fish for food, polar bears have gotten considerably
skinnier. Polar bear biologist Ian Stirling has found a similar pattern in Hudson
Bay. He fears that if sea ice disappears, the polar bears will as well.
http://environment.nationalgeographic.com/e
nvironment/global-warming/gw-effects/
Political Controversy?
• A poll of 1000s of scientific papers on climate
change found “97% endorsed the… position
that humans are causing global warming”
(IOPscience)
• So what’s the problem?
What are some of the Myths about
Climate Change?
http://youtu.be/OWXoRSIxyIU
Let’s do some math!!
• Goal: To calculate how much CO2 your bus
put into the atmosphere on the way to school
• First we need to make some assumptions:
– How far does the bus need to drive to school?
– Assume your bus burns diesel, and gets about 10
mpg*
– All the fuel is burned and turns into CO2
*https://answers.yahoo.com/question/index?q
id=20130725055457AAVzUO7
Diesel Fuel Numbers
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School bus fuel economy: ~10 mi/gal
Carbon weight percent: 84.86%
Diesel fuel Density: ~0.832 kg/l= 3.14 kg/gal
Weight % Carbon in CO2 =27.7%
• So if your school bus drives 5 miles to school
(conservative estimate), how many kilograms
of CO2 does your bus emit
Calculation
5𝑚𝑖
10𝑚𝑖 = .5 𝑔𝑎𝑙 𝑑𝑖𝑒𝑠𝑒𝑙 𝑏𝑢𝑟𝑛𝑒𝑑
𝑔𝑎𝑙
3.14𝑘𝑔
. 5 𝑔𝑎𝑙 ∗
= 1.57 𝑘𝑔 𝑔𝑎𝑠 𝑏𝑢𝑟𝑛𝑒𝑑
𝑔𝑎𝑙
1.57 𝑘𝑔 ∗ .8486 = 1.33 𝑘𝑔 𝐶 𝑒𝑚𝑖𝑡𝑡𝑒𝑑
1.33𝑘𝑔
= 4.88𝑘𝑔 𝐶𝑂2
.2727
Or .976 kg CO2 emitted per mile
So how much is that really?
• Well, dry ice is solid CO2, let’s see how much
that is in a balloon
• Now multiply that by:
– All the busses at your school
– All the busses in the US (480,000)
– Add all the people driving to work every day on
top of that (cars get better gas mileage, but are
less efficient… why?)
THAT’S A LOT!
So what can we do about it?
• Fossil fuels are the source of most of the CO2 in
the atmosphere
– Natural gas offers a short term solution (CH4 is more
energy dense than oil, but has it’s own environmental
problems)
– Biomass offers a good opportunity– plants intake CO2
over their lifetime, and when they are burned that
CO2 is put back into the atmosphere creating a carbon
neutral cycle
– Carbon sequestration techniques (such as burying the
CO2) offer some expensive answers
End Goal
• We need to reduce the amount of greenhouse gas in
the atmosphere
• Technology offers some solutions, but change needs to
happen rapidly on both a political and social front
– Largest climate change rally ever held a few months ago in
NY
– UN summit on climate change gained a lot of attention last
week as well
– The Rockefeller trust fund is divesting completely from
non-renewable energy funds
• We need to be more cognizant of how our actions will
impact the world around us!
If you want more…
“Years of Living Dangerously” on Showtime,
available for download