Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Make your likes visible on Facebook?

Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.

No, thanks

Ch 19 Climate Change and Ozone Depletion

No description
by

Valerie Head

on 11 April 2016

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Ch 19 Climate Change and Ozone Depletion

Ch 19 Climate Change
and Ozone Depletion
Core Case Study: Studying a Volcano to Understand Climate Change
1. In 1991, Mount
Pinatubo
erupted, which allowed
scientists to further study global
climate
change.
2. Scientists studied that amount of
SO2
released by the
volcano to determine if pollutants would indeed change the
climate of the Earth on a larger scale. It does.
19-1: How Might the Earth's Temperature
& Climate Change in the Future?
For the past 900,000 years the Earth has experienced period of global
cooling
and global
warming
. For the past 1,000 years the temperature has been
stable
, but has begun to
rise
in the last century when people began
clearing forests and burning fossil fuels.
How are past temperatures determined?
Radioisotopes in
rocks and fossils
Bubbles of ancient
air
in ice cores
Temperature taken at different depths of the Earth
Historical Records
Life on Earth wouldn’t be possible without the natural
greenhouse effect
:
-
warms
the Earth’s lower atmosphere
and surface due to greenhouse gasses like
CO2, water vapor, and CH4
that trap heat
from the sun
So what's the problem?
The problem is when we have
too many
greenhouse gases and
human
activities have led to this increase.
-Mainly due to agriculture,
deforestation
,
and burning
fossil fuels
At our current rate of emission of CO2 we will have a concentration of
560
ppm by 2050, and according to research the
tipping
point is
450
ppm.
Top 2 CO2 emitting countries:
1. China
2. US
Data from
ice
cores also shows that 60% of
methane
emissions is due to
human
activity from extracting fossil fuels,
landfills,
and livestock.
Nitrous Oxide levels have also increased due to use of Nitrogen
fertilizers.
Evidence For
Climate Change

1.Between 1906-2000, average global surface temp has increased by
1.3 F
2. Greenhouse gas emissions has risen
70%
since 1970
4.
Glaciers
and floating sea ice are melting
3.
Arctic
temps have risen twice as fast in the past 50 years
5. Rainfall patterns are changing
6. Sea level has risen by 4-8 inches
What Role Does the Ocean Play?
- Oceans absorb
half
of all of the
CO2
released and help moderate temperature
- Some Carbon is
converted to carbonate
salts that are buried in the sediments for millions of years
-
Solubility
of CO2 decreases with
warmer
temperatures

-As water heats, the CO2 isn't absorbed as easily and can amplify global warming=
positive
feedback loop
-Higher levels of CO2 increases the
acidity
of the ocean, which decreases the ability of
corals
to make calcium carbonate shells

**Bottom Line: Temperature, acidity, and ability to absorb CO2 from atmosphere are changing as a result of human activities
19-2: What are Some Possible Effects of a Warmer Atmosphere?
19-3: What Can We Do to Slow Climate Change?
Why is this complex problem is difficult so tackle:?
1. The problem is
global
- much international cooperation
2. Effects of climate change will last a long time- CO2 stays in atmosphere
120 years
3. It is a long term
political
issue.
4. Impacts of climate change are not spread
evenly
across the globe.
5.Phasing out fossil fuels would disrupt
economies
and lifestyles.
Solutions: Three Major Prevention Strategies-
1. Improve energy
efficiency
to reduce fossil fuel use.
2. Shift from nonrenewable
Carbon
based fossil fuels to a mix of Carbon
free
renewable energy resources.
3. Stop cutting down tropical
rainforests
.
** Effectiveness of these strategies would be enhanced by reducing
population
and reducing
poverty
.
Output Strategies for Reducing Climate Change:
1. Massive
tree
planting on degraded land in the tropics.
2. Plant fast growing perennial plants like
switchgrass- stores CO2 in
soil
to be
harvested for
biofuels
.
3. Carbon Capture & Storage (CCS)- removing
CO2 from
smokestacks
and pumping it
deep into
coal beds
or abandoned oil or
gas fields
-CCS is expensive and could raise prices
-require large inputs of
money
to operate=
counterproductive
-earthquakes, war, etc could cause a

leak
; even a small leak would be disastrous
Random Suggestions:
1. Inject sulfate particles into
stratosphere
-reflects
sunlight
to cool troposphere
2. “Re-ice” the
Arctic Sea
.
3. Deep sea
pipes
to bring up nutrients for algal blooms which can take in
CO2
What Can the Government Do to Slow Climate Change?
1. Strictly regulate
CO2
and
methane
pollutants.
2. Carbon taxes
3.
Cap and Trade
Approach
4.
Subsidies
to businesses who use green technologies
5.Technology transfer to
developing
countries
*
Kyoto
Protocol- a treaty to slow climate change (2005)
-requires countries to cut emissions of
Co2, CH4, and N2O
by 5.2% of their 1990 levels by 2012.
-countries can
trade
greenhouse gas emissions- the “cap and trade” system
-174 countries agreed to this. The US
DID NOT
.

*George W. Bush decided not to comply because he felt it would harm the
economy
and he did not like how rapidly developing countries (like
China
) were
exempt.

Costa Rica
aims to be the first carbon
neutral
country. They currently generate 78% of their electricity from renewable
hydroelectric
power and 18% from
wind
and
geothermal
energy!

Some US States are tired of waiting on the federal government to take charge.
Who's Been Successful?
Portland, Oregon- 1st city to cut greenhouse gas emissions back to
1990
levels.
*The city promotes energy efficient
buildings
and use of electricity from
wind
and
solar
sources.
*Has built many bicycle trails & has greatly expanded
mass transit
.
*This has actually produced an economic
boom
and has saved the city
$2 million
/year in energy costs!
California- 12th largest producer of greenhouse gases (GHG) in the WORLD!

*2006- CA passed a law to cut GHG to
25%
below 1990 levels by 2020.
*Set fuel efficiency and carbon emissions standards and let the free market find the best ways to meet standards- EPA refused this request. CA and 17 other states are now suing the federal government to allow states to set tougher CO2 emission standards.
Companies and Schools are reducing their Carbon Footprints
 DuPont, IBM, Toyota, & Walmart have cut GHG emissions
Harmful Effects of Climate Change:
Global climate models say we must make a
50-85%
cut in GHG emissions by 2050 so prevent Earth from heating up more than 3.6°F, which will likely be difficult to do. Therefore, analysts have compiled a list of things we need to do to prepare for the long-term effects of climate change. See Picture.
19-4: How Have We Depleted Ozone in the Stratosphere and What Can Be Done About It?
Not only is there considerable thinning of the ozone in the polar regions, but there is overall thinning everywhere as well, except over the tropics.

Ozone depletion in the
stratosphere
poses a serious threat to
humans
, animals, and
primary producers
.
Chloroflurocarbons
*Discovered in
1930
and use expanded rapidly
*Trade name =
Freons
*Thought to be the dream chemical because it is chemically unreactive,
nonflammable
, nontoxic,
inexpensive
, and
noncorrosive.
*Became popular as
coolants
in ACs, refrigerators, cleaners for electric parts, propellant in spray cans, aerosols, etc.
*Too good to be true: 1974- “CFCs destroy
ozone
in stratosphere” said Rowland and Molina
-CFCs rise and remain in atmosphere
-Once CFCs reach atmosphere, it breaks
down under the influence of the
UV
which releases a highly reactive
Chlorine

which break O3 into O2 and O
-CFCs persist in atmosphere for
65-385
years

-It took Rowland and Molina 14 years to
convince DuPont to stop production
Why Should We Worry about Ozone Depletion?
1. More damaging
UV-B
and
UV-C
radiation reaches the Earth’s surface.
2. Sunburns, skin
cancers
3. Destroy
phytoplankton
- they play
a key role in removing
CO2
and are
the base of ocean food web
How Can We Reverse Stratospheric Ozone Depletion?
1. Stop use of all ozone depleting chemicals
2. Montreal Protocol- treaty’s goal is to cut
CFC
emissions by 35%
(The US agrees with this one!)
Can One Degree Actually Make a Difference???
Full transcript