Download Global warming and the Carbon Cycle

Carbon Cycle and
Climate Change
Mrs. Cook
Environmental Science
Global Warming
• “What gets us into trouble is not what we
don’t know…
it’s what we know and do nothing about.”
-Margaret Meid
The Carbon Cycle
• Producers convert carbon dioxide in the atmosphere
into carbohydrates during photosynthesis.
• Consumers obtain carbon from the carbohydrates in
the producers they eat.
•During cellular respiration, some of the carbon is
released back into the atmosphere as carbon dioxide.
Some carbon is stored in limestone, forming one of the
largest “carbon sinks” on Earth.
The Carbon Cycle
• Carbon stored in the bodies of organisms as fat, oils,
or other molecules, may be released into the soil or
air when the organism dies.
• These molecules may form deposits of coal, oil, or
natural gas, which are known as fossil fuels.
• Fossil fuels store carbon left over from bodies of
organisms that dies millions of years ago.
The Carbon Cycle
• Humans burn fossil fuels, releasing carbon into the
atmosphere.
• The carbon returns to the atmosphere as carbon
dioxide.
• Increased levels of carbon dioxide may contribute to
global warming.
The Carbon Cycle
The Carbon Cycle
http://www.youtube.com/watch?v=HrIr3xDhQ0E
What is the Difference between Climate and
Weather?
• Weather is an event such as rain, snow, wind, sunshine,
fog, frost, etc. that occurs on a particular day in a
particular place.
• Climate is an average of all the of weather in a particular
place over a period of time (usually a 30 year period)
and includes all the extremes (high and low temps, super
storms, blizzards, etc) for that period of time.
Climate Change
• Climate change is neither new or unusual.
• The earth’s average surface temperature and climate
have been changing throughout the world’s 4.7-billionyear history
- Sometimes gradually (over hundreds to millions of
years)
- Other times fairly quickly (over a few decades)
Climate Change
17
Average surface tem
perature (°C)
• Over the past 900,000
years there have been
time periods of cooling
and warming.
Average temperature over past 900,000 years
16
15
14
13
12
11
• For the past 10,000
years we have had the
good fortune of a stable
climate
Average surface temperature (°C)
10
9
900
800
700
600 500 400 300 200
Thousands of years ago
100 Present
Average temperature over past 130 years
15.0
14.8
14.6
14.4
14.2
14.0
13.8
13.6
1860 1880 1900 1920 1940 1960 1980 2000
Year
2020
The Greenhouse Effect
• For the earth to maintain a constant temperature
incoming solar energy must be balanced by an
equal amount of outgoing energy.
• Earth’s atmospheric gases, called greenhouse
gases, warm the lower atmosphere by absorbing
some of the infrared radiation (heat) radiated by the
earth’s surface.
The Greenhouse Effect
The Role of the Green House Effect:
• Discovered in 1896
• With no GHE the earth would be too cold
• If the GHE acted by itself the average surface
temperature would be 130o F
• Natural cooling takes place by:
• Releasing heat through evaporation
• Water vapor molecules rise to the clouds and
release heat into the upper atmosphere
• Actual average temperature: 59o F
The Greenhouse Effect
Primary Green House Gases:
• Water Vapor: Controlled by the hydrologic cycle
• Carbon Dioxide: Controlled by the carbon cycle
Evaluation of ancient glacial ice reveals:
• Water vapor levels have been relatively constant
over the past 160,000 years
• Carbon dioxide levels have fluctuated
• Fluctuations in global carbon dioxide levels
correspond with the fluctuation of the global
temperature
The Greenhouse Effect
Temperature change (°C) from 1980–99 mean
1.2
Observed
1.0
Model of greenhouse
gases + aerosols +
solar output
0.8
0.6
0.4
0.2
0.0
-0.2
1860
1880
1900
1920
1940
Year
1960
1980
2000 2010
http://www.youtube.com/watch?v=Hi3ERes0h84
Climate Change and Human Activities
•
Since the Industrial Revolution (1750) there has been a
sharp rise in:
1. Use of fossil fuels
2. Deforestation and burning grasslands to raise
crops
3. Cultivating rice and using fertilizer that releases
N2O
Climate Change and Human Activity
• A typical (500 megawatt)
coal plant burns 1.4 million
tons of coal each year.
There are about 600 U.S.
coal plants.
• Coal generates 54% of our
electricity.
• Burning coal causes smog,
soot, acid rain, and toxic air
emissions
Climate Change and Human Activities
•
700 million gasoline burning motor vehicles (555 million
of them are cars)
•
Emissions from US factories and power plants produce
more CO2 than the combination of 146 nations (75% of
the world population)
US Carbon Dioxide Emissions by Source
• The combustion of
fossil fuels to
generate electricity
is the largest
single source of
CO2 emissions in
the nation,
accounting for
about 40% of total
U.S. CO2
emissions and
33% of total U.S.
greenhouse gas
emissions in 2009.
http://www.epa.gov/climatechange/ghgemissi
ons/gases/co2.html
US Carbon Dioxide Emissions by Source
• The combustion of
fossil fuels, such as
gasoline and diesel to
transport people and
goods, is the second
largest source of CO2
emissions, accounting
for about 31% of total
U.S. CO2 emissions
and 26% of total U.S.
greenhouse gas
emissions in 2010.
http://www.epa.gov/climatechange/ghgemissi
ons/gases/co2.html
US Carbon Dioxide Emissions by Source
• The production and
consumption of mineral
products such as cement,
the production of metals
such as iron and steel,
and the production of
chemicals accounted for
about 14% of total U.S.
CO2 emissions and 20%
of total U.S. greenhouse
gas emissions in 2010.
• Note that many industrial
processes also use
electricity and therefore
indirectly cause the
emissions from the
electricity production.
http://www.epa.gov/climatechange/ghgemissi
ons/gases/co2.html
US Carbon Dioxide Emissions
U.S. Carbon Dioxide Gas Emissions, 1990-2010
Note: All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions
and Sinks: 1990-2010.
2008 Global CO2 Emissions from Fossil Fuel Combustion
and some Industrial Processes (million metric tons of CO2)
• These data
include CO2
emissions from
fossil fuel
combustion, as
well as cement
manufacturing
and gas flaring.
Together, these
sources represent
a large proportion
of total global
CO2 emissions
Source: National CO2 Emissions from Fossil-Fuel Burning,
Cement Manufacture, and Gas Flaring: 1751-2008.
2008 Global CO2 Emissions from Fossil Fuel Combustion
and some Industrial Processes (million metric tons of CO2)
• Changes in land use
can be important global estimates
indicate that
deforestation can
account for 5 billion
metric tons of CO2
emissions, or about
16% of emissions
from fossil fuel
sources. Tropical
deforestation in
Africa, Asia, and
South America are
thought to be the
largest contributors to
emissions from landuse change globally.
Source: National CO2 Emissions from Fossil-Fuel Burning,
Cement Manufacture, and Gas Flaring: 1751-2008.
Results of increased CO2 Emissions
• Most climate scientists believe that the
increased input of CO2 will…
1. Enhance the earth’s natural greenhouse
effect
2. Raise the average global temperature of the
atmosphere near the surface of the earth“GLOBAL WARMING”
Are we experiencing Global Warming?
• The following facts are based on analysis of ice cores,
temperature measurements in hundreds of boreholes
into the earths surface and atmospheric temperature
measurements
• CO2 concentrations are at their highest level in the
past 20 million years
• 75% of human caused CO2 emissions are from the
burning of fossil fuels
• The 20th century is the hottest in the past 1000 years
• Since 1861 the global temperature has risen 1.1o F
• 10 hottest years on record have occurred since 1990
http://www.youtube.com/watch?v=ab6jV4VBWZE&feature=related
Evidence of Climate Change
• Melting of land based ice caps and floating ice
at the poles and Greenland
• Shrinking of glaciers
• Average sea level rise of 4-8” over the past
100 years
• Northward migration of some fish, tree and
other species to find an optimal temperature
• Early spring arrival and late autumn frosts
• http://www.nbcnews.com/video/nightlynews/48995166#48995166
Evidence of Climate Change
• Glacier National Park
This dramatic comparison between 1920 and 2008 show the incredible mass,
thickness and width of the famous Grinnell glacier that has melted due to climate
change.
Argentina's Upsala Glacier was once the biggest in South
America, but it is now disappearing at a rate of 200 meters
per year.
The image is from an 1859 etching of the Rhone glacier in Valais,
Switzerland, and shows ice filling the valley.
In 2001, the glacier had shrunk by some 2.5km, and its 'snout' had
shifted about 450 meters higher up.
• Rising tides
• Some scientists predict that a warmer climate will trigger more violent
storms, which will cause increased rates of coastal erosion. This is a
section of shoreline at Cape Hatteras in North Carolina in the USA,
pictured in 1999 and 2004.
More pests
Tree-eating wood beetles are likely to benefit from a warmer climate and
reproduce in ever-increasing numbers.
These images show damage to White Spruce trees in Alaska caused by the
pests.
As the climate warms up, mountainous regions may experience
lower levels of snowfall. This image shows Mount Hood in Oregon
at the same time in late summer in 1985 and 2002.
http://www.youtube.com/watch?v=eIZTMVNBjc4
Climate Change
Early Warning signs from the Arctic:
• The poles are heating faster than the rest of the
earth
•
The ice in the Arctic Sea is large enough to cover
the USA and is sensitive to air temperatures
•
Temperatures in the Arctic have increased much
faster than the average global temperature
Climate Change
What will happen if the Arctic Ice
Melts?
• Greatly amplify warming of the
Arctic region
• Reroute warm ocean currents
• Could cause significant cooling in
parts of the northern hemisphere
• Especially bad cooling in Europe
and Eastern North America
• Tundra soil has warmed up so
much that it is releasing more CO2
than it is taking in.
Climate Change
News from Antarctica:
• Antarctica has 70% of the
worlds fresh water and 90%
of the reflective ice
• Since 1947 the temperatures
have increased 10oF in the
winter and 4.5oF in the
summer.
• Ice the size of Delaware
have broken off
• Ice melting off the continent
adds to the water volume to
raise sea levels
Climate Change
Problems in Greenland:
• The worlds largest island (3x the
size of Texas)
• If the glaciers melt as they did
110,000-130,000 years ago:
1.Average sea levels would rise
13-20 feet
2.Massive flooding in the low lying
coastal areas and cities
3.Could shut down the Gulf
Stream and North Atlantic
Current which keeps Europe
warmer than it naturally would
be
http://www.youtube.com/watch?v=cqjO8rwB-GI
http://www.youtube.com/watch?v=_Psue0AlIbE
Role of Ice on Global
Warming
The Ice Albedo
Feedback System:
• As the ice melts the water
that results absorbs more
heat speeding up the
warming process
• The light color of ice
reflects 80% of the
sunlight, if it melts the
ocean will be dark and
absorb 80%
Role of Ice on Global Warming
Oceans Moderate the Surface Temperatures:
• Removes 29% of the CO2, but water is less capable of
dissolving gas as the temperature increases
• As the temperature increases CO2 will bubble out of the
oceans.
• Oceans store heat energy deep in the water and may
release it into the atmosphere
• There is a conveyor belt that transfers heat around the
world that runs based on differences in water density.
Fresh water from melted ice may throw the system off.
http://www.youtube.com/watch?v=Hu_Ga0JYFNg
http://www.youtube.com/watch?v=mDyDmLUxVsE
http://www.youtube.com/watch?v=fvnnRHx5-ug
Climate change and wildlife
Those affected:
• Melting ice in the arctic reduces habitat
for polar bears- they need the ice to hunt
for food.
• warmer waters can kill coral reefs, which
countless marine species depend on for
food and shelter
• Droughts caused by changes in rain
patterns reduce food supply such as
desert grasses and flowering plants for
the critically endangered Sonoran
pronghorn
Climate Change and Wildlife
• warmer temperatures increase the
amount of time pests have to grow and
multiply, like the pine bark beetle that is
devastating forests all over North
America.
• Certain seal species that rarely come
to land, such as the harp seal, spotted
seal and the ringed seal, depend on
Arctic sea ice. Not only does sea ice
provide a home for resting, giving birth
and raising pups, it is also a feeding
ground for some of them. Icedependent seal species are likely to
have difficulty adapting to ice-free
summers
Climate Change and Wildlife
• Ivory gulls nest on rocky cliffs and fly
out to the sea ice to fish through
cracks in the ice and scavenge on
top of the ice. A retreat of sea ice
away from the coastal nesting sites
would have serious consequences.
• The ice edge in coastal areas is an
important feeding ground for the
walrus that use the ice as diving
platforms to feed on clams on the
sea floor. As the ice edge retreats
away from the continental shelves to
deeper areas, there will be no clams
nearby to feed on.
Climate Change and Wildlife
• The vast reduction in multiyear ice in the Arctic Ocean
is likely to be immensely disruptive to microscopic life
forms associated with the ice, as they will lack a
permanent habitat. Research in the Beaufort Sea
suggests that ice algae at the base of the marine food
web may have already been profoundly affected by
warming over the last few decades.
• Results indicate that most of the larger marine algae
under the ice at this site died out between the 1970s
and the late 1990s, and were replaced by lessproductive species of algae usually
associated with freshwater.
Chasing Ice 2
http://abcnews.go.com/International/video/capturingmelting-ice-glaciers-antarctica-22791324
http://www.cbsnews.com/8301-3445_16257548138/the-scientific-truth-about-climatechange/?tag=showDoorLeadStoriesAreaMain;Sun
MoLeadHero
• http://www.nbcnews.com/video/nightlynews/50018387#50018387
http://www.youtube.com/watch?v=lgxmOQRn_8c
http://www.youtube.com/watch?v=drINEQFXbPY