National Geographic: Six Degrees Could Change the World (2007)
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Starring: Alec Baldwin Director:
Ron Bowman Rating
Product Description |
U-Tube: https://www.youtube.com/watch?v=R_pb1G2wIoA
(1 Hr 36 Min)
Preview One Degree (2:08
minutes) on Nat Geo Channel:
http://channel.nationalgeographic.com/videos/degree-one/
Carbon Dioxide in Earth's Atmosphere
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The Keeling
Curve of atmospheric CO2 concentrations
measured at the Mauna Loa Observatory.
The concentration of carbon
dioxide (CO2) in Earth's atmosphere is approximately 392 ppm (parts per million) by volume as of 2011[1]
and rose by 2.0 ppm/yr during 2000–2009. [1][2]
The concentration with respect to pre-industrial concentration of 280 ppm has increased roughly exponentially with a growth rate
of 2.2% per year in the last decades[2] Carbon
dioxide is essential to photosynthesis in plants and other photoautotrophs, and is also a prominent greenhouse
gas. Despite its relatively small overall concentration in the atmosphere, CO2 is an important component of Earth's
atmosphere because it absorbs and emits infrared
radiation at wavelengths of 4.26 µm (asymmetric
stretching vibrational mode)
and 14.99 µm (bending vibrational mode), thereby
playing a role in the greenhouse effect in addition to other factors
such as water
vapour.[3]
The present level is higher than at any time during the last 800 thousand years,[4]
and likely higher than in the past 20 million years.[5]
Current concentration
Monthly average CO2
concentrations in 2003. High CO2 concentrations of ~385 ppm are in red,
low CO2, about ~360 ppm, is blue.
In 2009, the CO2 global average
concentration in Earth's atmosphere was about 0.0387% by volume,
or 387 parts per million by volume (ppmv).[1][6]
There is an annual fluctuation of about 3–9 ppmv
which roughly follows the Northern Hemisphere's growing season. The Northern Hemisphere dominates the annual cycle
of CO2 concentration because it has much greater land area and plant
biomass than the Southern Hemisphere. Concentrations peak in May as the
Northern Hemisphere spring greenup begins and reach a
minimum in October when the quantity of biomass
undergoing photosynthesis is greatest.[7]
Sources of carbon dioxide
Natural sources of atmospheric carbon
dioxide include volcanic
outgassing, the combustion
of organic matter, and the respiration processes of living aerobic
organisms; man-made sources of carbon dioxide include the burning of fossil
fuels for heating, power generation and transport, as
well as some industrial processes such as cement making. It is also produced by
various microorganisms from fermentation and cellular respiration. Plants convert carbon
dioxide to carbohydrates during a process called photosynthesis.
They gain the energy needed for this reaction through the absorption of
sunlight by pigments such as Chlorophyll. The resulting gas, oxygen, is released into
the atmosphere by plants, which is subsequently used for respiration by heterotrophic
organisms and other plants, forming a cycle.
Most sources of CO2 emissions
are natural. For example, the natural decay of organic material in forests and
grasslands, such as dead trees, results in the release of about 220 gigatonnes of carbon dioxide every year.[citation needed] In 1997, human-caused Indonesian peat fires
were estimated to have released between 13% and 40% of the average carbon
emissions caused by the burning of fossil
fuels around the world in a single year.[8][9][10]
Although the initial carbon dioxide in the atmosphere of the young Earth was
produced by volcanic
activity, modern volcanic activity releases only 130 to 230 megatonnes
of carbon dioxide each year,[11]
which is less than 1% of the amount released by human activities.[12]
These natural sources are nearly balanced
by natural sinks, physical and biological processes which remove carbon dioxide
from the atmosphere. For example, some is directly removed from the atmosphere
by land plants for photosynthesis and it is soluble in water forming carbonic
acid.
There is a large natural flux of CO2
into and out of the biosphere and oceans.[13]
In the pre-industrial era these fluxes were largely in balance. Currently about
57% of human-emitted CO2 is removed by the biosphere and oceans.[14]
The ratio of the increase in atmospheric CO2 to emitted CO2
is known as the airborne fraction (Keeling et al., 1995); this varies
for short-term averages but is typically about 45% over longer (5 year)
periods. Estimated carbon in global terrestrial vegetation increased from
approximately 740 billion tons in 1910 to 780 billion tons in 1990.[15]
Burning fossil fuels such as coal and petroleum is
the leading cause of increased anthropogenic CO2; deforestation
is the second major cause. In 2008, 8.67 gigatonnes
of carbon (31.8 gigatonnes of CO2)
were released from fossil fuels worldwide, compared to 6.14 gigatonnes
in 1990.[16]
In addition, land use change contributed 1.20 gigatonnes
in 2008, compared to 1.64 gigatonnes in 1990.[16]
In the period 1751 to 1900 about 12 gigatonnes of
carbon were released as carbon dioxide to the atmosphere from burning of fossil
fuels, whereas from 1901 to 2008 the figure was about 334 gigatonnes.[17]
This addition, about 3% of annual natural
emissions as of 1997,
is sufficient to exceed the balancing effect of sinks.[18]
As a result, carbon dioxide has gradually accumulated in the atmosphere, and as
of 2009,
its concentration is 39% above pre-industrial levels.[2]
Various techniques have been proposed for
removing excess carbon dioxide from the atmosphere in carbon dioxide sinks.
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The 2011
average annual concentration of CO2 in the atmosphere (Mauna Loa
Observatory) is 391.57 parts per million (
Here’s the review of the 6 degree book:
Six Degrees: The Book
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Author Mark Lyna
Au
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sIn
possibly the most graphic treatment of global Scientists
have established that the current episode of global warming of about 0.7
degrees Celsius (1.2 degrees Fahrenheit) in the last century has pushed
Earth’s temperatures up to levels unprecedented in recent history |
.
A 2007 report by the Nobel Peace Prize-winning UN Intergovernmental Panel on
Climate Change (IPCC) states that at no time in the past 1,300 years has our
planet been as warm as it is now, while records from the deep sea suggest that
temperatures are now within a degree of their highest levels in 1 million
years.
According
to the IPCC, Earth will warm up between 1.4 degrees Celsius and 5.8 degrees
Celsius (roughly 2 degrees Fahrenheit to 10 degrees Fahrenheit) by the end of
this century. Six degrees may not sound like much, but as this sobering and
engrossing book warns, such a rise in average temperature would be enough to
destroy much of life and reshape our world almost beyond recognition. Global
warming is already a fact: the snows of Kilimanjaro are melting away; massive boulders
on the Matterhorn, snowbound for centuries, have begun to plunge in dramatic
and dangerous rockfalls; and atoll nations of the
Pacific are disappearing inch by inch under the waves.
Basing
his conclusions on peer-reviewed articles in leading climatology, geophysics,
biology, and Earth system science journals, Lynas
explains in unflinching detail the processes and effects of this unprecedented
phenomenon, degree by degree. He draws on the latest research and sophisticated
computer models as well as paleoclimatic
reconstructions of the past that show conclusively that today’s climate change
is a new and different challenge, not the routine swing of a slow climatic
pendulum.
Lynas, journalist, campaigner, and
broadcaster on environmental issues, is also the author of High Tide: News
from a Warming World. He is a frequent contributor to New Statesman,
Ecologist, Granta, and Geographical
and other periodicals as well as the Guardian and Observer
newspapers in the United Kingdom. He lives in Wolvercote,
Oxford, U.K.
Watch the video on U-Tube:
http://channel.nationalgeographic.com/channel/sixdegrees/
http://www.youtube.com/watch?v=lZIF8TjqhSU