Transcript PPT File - Phoenix Union High School District

An Inconvenient Truth
An Introduction to our
Environmental Unit
Threats of Global Warming
in Our Future
Most global warming emissions remain in
the atmosphere for decades or
centuries. The energy choices we
make today greatly influence the
climate our children and grandchildren
inherit.
We have the technology to increase
energy efficiency, to significantly
reduce emissions from our energy and
land use, and to secure a high quality
of life for future generations.
We must act NOW to reduce dangerous
consequences.
Remember the hole in the
ozone layer? What happened to it?
In 1987, the nations of the world came
together to draft the Montreal Protocol
which would phase out the production
and use of CFCs (chloral floral carbons).
The 43 nations that signed the protocol
agreed to freeze consumption and
production of CFCs.
The alarming loss of ozone in Antarctica
and worldwide continued into the 1990's,
and additional amendments to further
accelerate the CFC phase-out were
adopted.
The pesticide methyl bromide, another
significant ozone-depleting substance
was phased out at the end of 2005.
The Montreal Protocol is working and
ozone depletion, due to human effects,
has decreased and will keep decreasing
in the next 10 years.
Provided that the Montreal Protocol is
followed, the Antarctic ozone hole is
expected to disappear by 2050.
Global Warming
Strong evidence that
warming is attributed to
human activities include:
– Loss of polar ice sheets.
– Global sea levels rising.
– Plants and animals
changing range and
behavior in response to
global temperature shifts.
– Plants and animals dying
and relocating.
– Global temperatures rising
yearly.
What is the Greenhouse Effect?
The greenhouse effect is
the rise in temperature that
the Earth experiences
because certain gases in
the atmosphere trap energy
from the sun.
Without these gases, heat
would escape back into
space and Earth’s average
temperature would be
about 60ºF colder.
These gases are referred to
as greenhouse gases
because of how they warm
the Earth.
The greenhouse effect maintains a livable
temperature on Earth. Generally, the Earth is in
balance. Problems arise when concentrations of
CO2 (carbon dioxide) and other greenhouse
gasses increase. Who increases CO2?
The Water Cycle &
Carbon Cycle
Water Cycle Animation
Carbon Cycle Animation
Increasing Emissions
Since the industrial
revolution, greenhouse
gases have increased
by:
Carbon Dioxide 30%
Methane
100%
Nitrous Oxide 15%
(The graph shows PPM, parts per
million, how gases are measured in
the atmosphere.)
Human Contribution to CO2
Humans are emitting more
greenhouse gases into the
atmosphere than ever
before.
We are wasteful with our
resources.
Cars, trucks, home and
business heating, and
power factories are
responsible for about 98%
of US carbon dioxide (CO2)
emissions and 18% of
nitrous oxide missions.
Fossil Fuel Emissions
Emissions per American
have increased (per
person).
Most of these emissions,
about 82%, are from
burning fossil fuels to
generate electricity and
power our cars.
Remaining emissions are
from methane from wastes
in our landfills, raising
livestock for food, natural
gas pipelines and coal.
Projected Future Emissions
World carbon dioxide emissions are
expected to increase by 1.9 percent a
year between 2001 and 2025. Much
of the increase in these emissions is
expected to occur in the developing
world where emerging economies,
such as China and India, fuel
economic development with fossil
energy. Developing countries’
emissions are expected to grow and
surpass emissions of industrialized
countries near 2018. Why?
The U.S. produces about 25 percent
of global carbon dioxide emissions
from burning fossil fuels; primarily
because our economy is the largest in
the world and we meet 85 percent of
our energy needs through burning
fossil fuels.
Warming of Oceans
Oceans comprise 97% of Earth's water. They have
an average depth of approximately 13,000 feet. It
takes a great deal of heat to raise the temperature
of this huge body of water, and the oceans have
absorbed the bulk of Earth's excess heat over the
past several decades.
These are
estimates of
the Earth’s
heat balance.
Glacial Melting

If only a small fraction of the heat currently stored in the oceans
were released, it would significantly warm the atmosphere and melt
the world's glaciers. Why do we need glaciers?

In reality, the circulation and redistribution of this excess heat is a
slow process. Even if we could maintain atmospheric CO2
concentrations at today's level, stored heat released by the oceans
will cause Earth's average surface temperature to continue rising
approximately one degree Celsius in the coming decades. What is
C compared to F in temperature?

To put this into perspective, this is the same as the global average
temperature rise that has occurred over the last century. The
warming of the oceans and the melting of glaciers, worldwide, have
already caused sea levels to rise, and most of this rise has come in
the past few decades (how long is a decade?).

CO2 trapped in glaciers will also be released, as they melt due to
higher temperatures, and this will cause a BIG increase when it
happens.
Melting of Snow & Ice
Half of Greenland’s ice sheet
naturally melts every summer.
But, in July 2010, 97% of the ice
sheet had melted.
The extent and duration of frozen
ground have declined in most
locations.
Alpine and polar glaciers have
retreated since 1961, and the
amount of ice melting in
Greenland has increased since
1979.
Over the past 25 years, the
average annual Arctic sea ice
area has decreased by almost five
percent and summer sea ice area
has decreased by almost 15
percent. The collapse of the
Larsen Ice Shelf off the Antarctic
Peninsula appears to have no
precedent in the last 11,000 years.
Can 1 degree C really make a
difference?
Pasterze Glacier in Austria
1875 vs. 2004
Portage Glacier in Alaska
1914 vs. 2004
Mount Hood in Oregon
1984 vs. 2002
Recent Activity – Canadian Glacier
On January 4th, 2006 it was
reported that a giant ice shelf the
size of 11,000 football fields
snapped free from Canada's
Arctic.
Scientists say it was the largest
event of its kind in Canada, in 30
years, and they point to climate
change as a major contributing
factor. They added that “the
remaining ice shelves are 90
percent smaller than when they
were when first discovered in
1906.” "We aren't able to
connect all of the dots ... but
unusually warm temperatures
definitely play a major role.“
Blog
Antarctic Ice and Pictures
Recent Activity - Droughts
We have certainly seen global
temperature increases and changes in
precipitation patterns over the 20th
century, resulting from human
activities. This has resulted in some
increases in extremes of temperatures
and precipitation.
These trends will continue in the
future, and there is concern that global
warming will cause climate variability
and extreme events (e.g., floods,
droughts, heat waves) to increase.
For instance, a scientific analysis
indicates human-induced climate
change likely increased the severity of
the 2003 European heat wave that
killed thousands of people.
The same study predicts that as
climate change progresses, similar
heat events will become normal rather
than exceptional.
Recent Activity - Smog
Right away, we should put
existing technologies for
building cleaner cars and
more modern electricity
generators into widespread
use. We need to reduce
pollution/smog.
We can increase our reliance
on renewable energy sources
such as wind, sun and
geothermal. And, we can
manufacture more efficient
appliances and conserve
energy. (Do you have Energy
Star appliances? What are
these?)
Recent Activity - Storms
In terms of overall hurricane activity (the number of
and intensity of storms), the 2005 Atlantic hurricane
season was the most active season on record.
Because of the link between higher ocean
temperatures and hurricanes, there is speculation
that hurricanes will increase in frequency or intensity
in a warmer world, with higher wind speeds and
greater precipitation. Scientists believe that global
warming will result in more intense hurricanes, as
increasing sea surface temperatures provide energy
for storm intensification.
Higher ocean temperatures may also influence the
tracks of hurricanes, increasing the likelihood of
hurricanes through the Caribbean or hurricanes
making landfall on the east coast (did this happen
recently?!). Although his phenomenon is not very
well understood, a track of unusually deep and
warm water appears to have led Katrina directly to
the Gulf Coast when it struck Louisiana and
Mississippi.
Rising Sea Levels
It is likely that much of the rise in sea
level has been related to the
concurrent rise in global
temperatures over the last 100
years.
On this time scale, the warming and
the consequent thermal expansion
of the oceans may account for about
2-7 cm of the observed sea level
rise, while the observed retreat of
the glaciers and ice caps may
account for about 2-5 cm.
The rate of observed sea level rise
suggests that there has been a net
positive contribution from the huge
ice sheets of Greenland and
Antarctica.
Computerized Rising Sea Level
Prediction
Article and Pictures
Warmest Years on Record
•
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•
13 of the 14 warmest years on record occurred this century, according to the
UN. They said last year continued a long-term warming trend, with the hottest
year ever in Australia and floods, droughts and extreme weather elsewhere
around the world. 2001-2010 was the warmest decade on record, the last three
decades had been warmer than the previous one.
The WMO's secretary-general, also said there had been no 'pause' in global
warming, as has been alleged by climate change sceptics. “There is no standstill
in global warming.”
Arctic sea ice in 2013 was at the sixth lowest on record. The WMO noted all
seven of the lowest Arctic sea-ice extents took place in the past seven years,
starting with 2007, which scientists were "stunned" by at the time.
"Many of the extreme events of 2013 were consistent with what we would expect
as a result of human-induced climate change. We saw heavier precipitation,
more intense heat, and more damage from storm surges and coastal flooding as
a result of sea level rise.
Our Changing Climate
Global mean surface
temperatures have
increased 0.5-1.0
deg C since the late
19th century
The 20th century’s
10 warmest years
have occurred in the
last 15 years!
Possible Scenarios
A warmer climate could result
in less winter snowfall, more
winter rain, and faster, earlier
spring snowmelt runoff.
In the summer, without
increases in rainfall of at least
15-20%, higher temperatures
and increased evaporation
could lower stream flows and
lake levels.
Less water would be available
to support irrigation,
hydropower generation, public
supply, fish and wildlife
habitat, recreation and mining.
Possibility of higher risk of
debris flows.
Agriculture
Agriculture is strongly
influenced by climatic
conditions and water
availability.
As climate warms, production
patterns could shift northward
and to higher elevations.
Increases in climate
variability could make
adaptation by farmers more
difficult.
Warmer climate and less soil
moisture may require
additional irrigation.
Forestry
Depending on the
amount of climate
change, the extent of
forested areas could
change little or decline
by as much as 15-30%.
Hotter, drier
temperatures could
increase frequency of
wildfires.
Insect outbreaks carrying
disease could increase
with warmer, drier
conditions.
How do we know all of this?
Scientists have to think like detectives. They look
for clues to help them understand how the world
works. Then they investigate the clues to find
evidence – real facts that can give them a better
idea of what is going on. Here are some of the
ways that scientists gather evidence about climate,
both past and present:
– Weather stations
– Weather balloons
– Ocean buoys
– Sediment analysis
– Tree rings
Weather stations, balloons, ocean buoys, and
satellites tell us the Earth’s temperature today. Ice
cores, sediment layers, and tree rings tell us about
what the Earth’s climate has been like in the past.
With this evidence, scientists are learning how
climate changes over time.
“How far can it go? The last time the world was three
degrees warmer than today – which is what we expect
later this century – sea levels were 25m higher. So that
is what we can look forward to if we don't act soon…I
think sea-level rise is going to be the big issue soon,
more even than warming itself…
How long have we got? We have to stabilize emissions of carbon
dioxide within a decade, or temperatures will warm by more than one
degree.
That will be warmer than it has been for half a million years, and
many things could become unstoppable.…We don't have much time
left.”
Dr. James Hansen, Director, NASA Goddard Institute for Space
Studies.
– The Independent 2/ 17/2006
Take Action at School!
Throughout history, students
have been the driving force in
social change. Now more than
ever is the time for students
across the country to become
global warming activists and join
the movement.
– Join the Virtual March
– Encourage Your Mayor to Take
Action
– Watch An Inconvenient Truth
– Replace School Lightbulbs
– No Idling!
– Recycle
– Cut Back on Paper
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Educate Your Parents
Use Timers
Take Action at Home
No Waste at School Meals and
Events
Plant Trees
Conduct a School Energy Audit
Replace Oil Burning Furnaces
Spread the News
Start a Club
Speak Out
Reward the Use of Hybrids
Audit Student's Energy Use
Review School's Purchases
Carpool
Take Action at Home!
Take Action Sheet