Transcript The Greenhouse Gases

What is the #1 threat to biodiversity?
Habitat Destruction!
The process by which natural habitat is damaged or
destroyed to such an extent that it no longer is capable of
supporting the species and ecological communities
that naturally occur there. It often results in the extinction of
species and, as a result, the loss of biodiversity.
Habitat can be destroyed directly
by many human activities, most
of which involve the clearing of
land for other uses such as
agriculture, mining, logging,
hydroelectric dams and
urbanization. Habitat can also
be destroyed indirectly by human
activities such as pollution,
climate change and the
introduction of invasive
species.
Although much habitat destruction
can be attributed to human activity, it
is not an exclusively man-made
phenomenon. Habitat loss also
occurs as a result of natural events
such as floods, volcanic
eruptions, earthquakes, and
climate fluctuations.
Deforestation is among the primary causes of habitat destruction
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What is an INVASIVE SPECIES?
A species is invasive when it is both non-native to the
ecosystem in which it is found and capable of causing
environmental, economic, or human harm.
Invasive species often compete so successfully in new
ecosystems that they displace native species and disrupt
important ecosystem processes. Plants, fish, insects,
mammals, birds, and diseases all can be invasive.
Invasive species are recognized as
one of the leading threats to
biodiversity and impose enormous
costs to agriculture, forestry, fisheries,
and other human enterprises, as well
as to human health.
In 2007 and 2008, more than 659,600 acres of trees
were defoliated by invasive gypsy moth caterpillars in
New Jersey, resulting in the death of about 31,000 acres’
worth of trees. The state spent $1.8 million to control
gypsy moths in 2009.
Often, invasive species owe their success in colonizing new ecosystems
to one or more of the following characteristics:
• They tolerate a variety of habitat conditions
• They grow and reproduce rapidly
• They compete aggressively for resources (like food, water,
and nesting sites)
• They lack natural enemies or pests in the new ecosystem
Invasive species can negatively impact
ecosystems in a variety of ways. They
can:
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Displace native species
Reduce native wildlife habitat
Reduce forest health and
productivity
Alter ecosystem processes
THE GREENHOUSE EFFECT
If it were not for greenhouse gases trapping heat in the atmosphere, the Earth
would be a very cold place. Greenhouse gases keep the Earth warm through a
process called the greenhouse effect.
The Earth gets energy from the
sun in the form of sunlight. The
Earth's surface absorbs some of
this energy and heats up. The
Earth cools down by giving off a
different form of energy, called
infrared radiation. Before all this
radiation can escape to outer
space, greenhouse gases in the
atmosphere absorb some of it,
which makes the atmosphere
warmer. As the atmosphere gets
warmer, it makes the Earth's
surface warmer, too.
The Greenhouse Gases
Those gas molecules in the Earth's atmosphere with three or more atoms are
called "greenhouse gases" because they can capture outgoing infrared energy
from the Earth, thereby warming the planet. The greenhouse gases include water
vapor (H2O), ozone (O3), carbon dioxide (CO2), and methane (CH4). Also, trace
quantities of chloro-fluoro-carbons (CFC's) can have a disproportionately large
effect.
Global Warming is issue of major
concern is the possible effect of the
burning of fossil fuels and other
contributors to the increase of
carbon dioxide in the atmosphere.
The action of carbon dioxide and
other greenhouse gases in trapping
infrared radiation is called the
greenhouse effect. It may
measurably increase the overall
average temperature of the Earth,
which could have disastrous
consequences.
The Main Greenhouse Gases
People produce more carbon dioxide than any other greenhouse gas, and it's
responsible for most of the warming.
Carbon Dioxide (54.7%)  (Stays in the atmosphere anywhere from 50 to
thousands of years)
Comes from:
• Burning fossil fuels to produce electricity and heat for buildings
• Burning gasoline & other fossil fuels to run vehicles
• DEFORESTATION – the cutting down and burning trees (that would
otherwise USE the carbon dioxide for photosynthesis)
Methane(30%)  (Stays in the atmosphere for 12 years – but traps more than 20
times the amount of heat as carbon dioxide)
Comes from:
• Farming  raising livestock, especially cows and sheep produce
methane as they digest food. Manure also releases methane as it
decays.
• Landfills  decaying trash releases methane
• Producing and transporting natural gas – even small leaks release
methane
Chlorofluorocarbons (CFCs)  time in
atmosphere varies up to thousands of
years and amount of heat trapped varies
from a few hundred to 23,000 times the
amount of trapped heat
It is used as a propellant in aerosol cans,
creating foam plastics, cooling
refrigerators and air conditioners, as a
solvent in cleaners, and as an ingredient
in fire extinguisher materials. These also
destroy the ozone layer.
Nitrous Oxide  stays in the atmosphere
114 years and traps almost 300 times
more heat than carbon dioxide
Farming practices that add nitrogen to the
soil (such as fertilizers), bacteria turns it
into nitrous oxide
What will be the effects of Global
Warming?
• When we talk about global
warming, we're not talking about
how this summer's temperatures
were hotter than last year's.
Instead, we're talking about
climate change, changes that
happen to our environment,
atmosphere and weather over
time. Think decades, not
seasons. The term global
warming itself is a bit deceptive
because it implies we should
expect things to get hotter -- not
necessarily stormier, drier and
even, in some instances, colder.
What can we expect from a planet undergoing
climate changes?
Rising Sea Level & Shrinking Glaciers
Hotter temperatures mean ice – glaciers, sea ice and
polar ice sheets -- is melting, increasing the amount of
water in the world's seas and oceans. Such levels
would submerge many of Indonesia's tropical islands
and flood low-lying areas such as Miami, New York
City's Lower Manhattan and Bangladesh.
Tundra once covered with thick permafrost is melting
with rising surface temperatures and is now coated
with plant life.
Heat Waves
Extreme heat waves are happening two to four times
more often now, steadily rising over the last 50 to 100
years, and are projected to be 100 times more likely
over the next 40 years Experts suggest continued heat
waves may mean future increases in wildfires, heatrelated illness and a general rise in the planet's mean
temperature.
Storms and Floods
In just 30 years the occurrence of the
strongest hurricanes -- categories 4 and
5 -- has nearly doubled.
Drought
While some parts of the world may find
themselves deluged by increasing storms and
rising waters, other areas may find
themselves suffering from drought. As the
climate warms, an increase in drought
conditions leads quickly to a shrinking water
supply and a decrease in quality agricultural
conditions. This puts global food production
and supply in danger and leaves populations
at risk for starvation.
Worldwide droughts, like that in a village northeast of
Nairobi, expose rural communities to food shortages.
Disease
Warmer temperatures along with associated floods and droughts are encouraging
worldwide health threats by creating an environment where mosquitoes, ticks, mice
and other disease-carrying creatures thrive. The World Health Organization (WHO)
reports that outbreaks of new or resurgent diseases are on the rise and in more
disparate countries than ever before, including tropical illnesses in once cold climates
-- such as mosquitoes infecting Canadians with West Nile virus.
Cases of allergies and asthma are also increasing. Global warming fosters increased
smog -- which is linked to mounting instances of asthma attacks -- and also advances
weed growth, a bane for allergy sufferers.
A field sample of mosquitoes that could carry West Nile virus pictured in California. Image Credit: David McNew/Getty Images
Economic Consequences
The costs associated with climate change rise along with the
temperatures. Severe storms and floods combined with
agricultural losses cause billions of dollars in damages, and
money is needed to treat and control the spread of disease.
Extreme weather can create extreme financial setbacks. For
example, during the record-breaking hurricane year of 2005,
Louisiana saw a 15 percent drop in income during the months
following the storms, while property damage was estimated at
$135 billion
Economic considerations reach into nearly every facet of our
lives. Consumers face rising food and energy costs along with
increased insurance premiums for health and home.
Governments suffer the consequences of diminished tourism
and industrial profits, soaring energy, food and water
demands, disaster cleanup and border tensions.
Conflicts and War
Scientists and military analysts alike are theorizing climate change and its
consequences such as food and water instability pose threats for war and
conflict, suggesting that violence and ecological crises are entangled. Countries
suffering from water shortages and crop loss become vulnerable to security
trouble, including regional instability, panic and aggression.
Loss of Biodiversity
Species loss and endangerment is rising along with global
temperatures. As many as 30 percent of plant and animal species
alive today risk extinction by 2050 if average temperatures rise
more than 2 to 11.5 degrees F (1.1 to 6.4 degrees C). Such
extinctions will be due to loss of habitat through desertification,
deforestation and ocean warming, as well as the inability to adapt
to climate warming. Humans also aren't immune to the threat.
Desertification and rising sea levels threaten human habitats. And
when plants and animals are lost to climate change, human food,
fuel and income are lost as well.
Destruction of Ecosystems
Changing climatic conditions and dramatic increases in carbon
dioxide will put our ecosystems to the test, threatening supplies of
fresh water, clean air, fuel and energy resources, food, medicine
and other matters we depend upon not just for our lifestyles but
for our survival.
Forecasts of famine, war and death paint a dire picture of climate
change on our planet. Scientists are researching the causes of
these changes the vulnerability of Earth not to predict the end of
days but rather to help us mitigate or reduce changes that may be
caused by humans. If we know and understand the problems and
take action through adaptation, the use of more energy-efficient
and sustainable resources and the adoption of other green ways
of living, we may be able to make some impact on the climate
change process.
Again…HOW CAN WE ALL HELP TO REDUCE OUR
CARBON FOOTPRINT?!
These greenhouse gases don't just stay in one place after they're added to the atmosphere. As air moves
around the world, greenhouse gases become globally mixed, which means the concentration of a
greenhouse gas like carbon dioxide is roughly the same no matter where you measure it. Even though some
countries produce more greenhouse gases than others, emissions from every country contribute to the
problem. That's one reason why climate change requires global action.
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Turn it off  Turn off lights, televisions, videos,
stereos and computers when not in use - they can use
10 to 40% of the power when on standby. Also, unplug
chargers as soon as they have finished charging.
Be exact  Use only as much water as you need.
Close it  Don't leave fridge doors open for longer
than necessary.
• Use no plastic  Use cloth bags when going shopping and avoid buying
products which use too much plastic.
• Fan up  Instead of using air conditioners in the summer, wear cool clothes,
and use a fan.
• Drive less  Do your weekly errands in a single trip or pay your bills online.
Walk, bike, ride the bus or carpool.
• Optimize your speed  You will consume up to 25% less fuel if you drive
no more than 50 mi/hr.
• Drive hybrid  A hybrid or other fuel-efficient car emits less carbon dioxide.
• Replace them  Replace your incandescent bulb with a compact
fluorescent light bulb (CFL). CFLs cost 3 to 5 times as much but use less
than a third of the power. Also, replace old fridge and other appliances with
energy-efficient ones
• Recycle  Consume less, and re-use old products.
Effects of habitat loss:
DEFORESTATION
The cutting down of trees causes several ecological effects:
1 – Without the trees to absorb the water, much of the minerals
(particularly nitrogen) is lost in the soils from the runoff.
2- With the loss of plant life, less carbon dioxide is absorbed
(through photosynthesis) making higher levels of CO2 in the
atmosphere, contributing to global warming!
Net losses of water were 3040% greater in the deforested site than the
undisturbed (control) site.
Also, nitrate levels increased 60 times in the outflow of the deforested site.
Restoration ecologists help return
degraded ecosystems to a
more natural state
• Given enough time, biological communities can recover
from many types of disturbances
• Restoration ecology seeks to initiate or speed up the
recovery of degraded ecosystems
• Two key strategies are bioremediation and
augmentation of ecosystem processes
© 2011 Pearson Education, Inc.
Bioremediation
• Bioremediation is the use of living organisms to
detoxify ecosystems
• The organisms most often used are prokaryotes, fungi,
or plants
• These organisms can take up, and sometimes
metabolize, toxic molecules
– For example, the bacterium Shewanella oneidensis can
metabolize uranium and other elements to insoluble
forms that are less likely to leach into streams and
groundwater
© 2011 Pearson Education, Inc.
Figure 55.18a
Biological Augmentation
• Biological augmentation uses organisms to add essential
materials to a degraded ecosystem
– For example, nitrogen-fixing plants can increase the
available nitrogen in soil or adding mycorrhizal fungi can
help plants to access nutrients from soil
However, addition of nutrients to an ecosystem does NOT
always have a positive ef….
The addition of large amounts of nutrients to lakes has a wide
range of ecological impacts  not always for the better!
In some areas, sewage runoff containing fertilizers has caused
eutrophication of lakes, which can lead to loss of most fish
species
© 2011 Pearson Education, Inc.
Eutrophication
The process by which a body of water acquires a high concentration of
nutrients, especially phosphates and nitrates. These typically promote
excessive growth of algae  which depletes the water of oxygen and
nutrients for other organisms.
Eutrophication often
comes from runoff,
containing phosphorous
and nitrogen from
fertilized soils &
contaminated water .
This has led to the use of phosphate-free detergents!
An algal bloom or a “red tide”
An algal bloom or a “red tide” is a rapid increase or accumulation in the population of
algae (typically microscopic) in an aquatic system. These deplete oxygen and nutrients
for other organisms to survive! Some algal blooms add toxins to the environment.
BIOMAGNIFICATION
The increasing concentration of
a substance, such as a toxic
chemical, in the tissues of
organisms at successively
higher levels in a food chain. As
a result of biomagnification,
organisms at the top of the food
chain generally suffer greater
harm from a persistent toxin or
pollutant than those at lower
levels
DDT (dichlorodiphenyltrichloroethane) is an organochlorine insecticide which is
a colorless, crystalline solid, tasteless and almost odorless chemical compound.
First synthesized in 1874, DDT's insecticidal properties were not discovered
until 1939, and it was used with great success in the second half of World War II
to control malaria and typhus among civilians and troops.
The Swiss chemist Paul Hermann Muller
was awarded the Nobel Prize in
Physiology or Medicine in 1948 "for his
discovery of the high efficiency of DDT as
a contact poison against several
arthropods.“ After the war, DDT was made
available for use as an agricultural
insecticide, and soon its production and
use skyrocketed.
In 1962, Silent Spring by
American biologist Rachel
Carson was published. The
book catalogued the
environmental impacts of the
indiscriminate spraying of DDT
in the US and questioned the
logic of releasing large amounts
of chemicals into the
environment without fully
understanding their effects on
ecology or human health.
The book suggested that DDT and other pesticides may cause cancer and
that their agricultural use was a threat to wildlife, particularly birds. Its
publication was one of the signature events in the birth of the environmental
movement, and resulted in a large public outcry that eventually led to DDT
being banned in the US in 1972.
Along with the passage of the Endangered
Species Act, the US ban on DDT is cited
by scientists as a major factor in the
comeback of the bald eagle, the national
bird of the United States, from nearextinction in the US.