Transcript The Big Picture: The Earth at Risk

The Big Picture: The Earth at Risk
From: www.environmentadefense.org
www.iucnredlist.org
Four Laws of Ecology
•
Keep these laws in mind as you view the
slides and information that follow:
1. Everything is connected to everything else.
2. Everything goes somewhere – possibly in a
different form but virtually nothing goes
totally out of existence
3. Nature knows best – all molecules
constructed by nature are biodegradable –
not all molecules made by humans are.
4. There’s no such thing as a free lunch –
every action has consequences that ripple
out triggering other actions.
Moose
• A warming trend in Alaska over the
past three decades - higher
temperatures that last longer during
the year - is evidenced in the melting
of the permafrost. This change in
habitat means trouble for animal
species such as moose. (Credit: U.S.
Geological Service)
Polar Bears
• Polar bears in the southern
range, for instance, who hunt for
much of their prey on sea ice,
experience shorter hunting
seasons now that sea ice melts
earlier in the spring and freezes
later in the fall. (credit: Gene
Augustine/NOAA)
More on Polar Bears
• The most carnivorous of the worlds’
bears, the polar bear has long reigned at
the top of the arctic food chain. Superbly
adapted to prowling for prey on the ice,
this bear has met one enemy it cannot
vanquish: climate change. As ice packs
thin and melt earlier, bears go hungry.
Scientists have already noted population
declines and more bears drowning as
they try to swim for their prey.
Sea Otter
• In some areas of Alaska, sea otter
populations are plummeting, and their plight
underscores the complexity of marine
ecosystems. Scientists are finding that killer
whales are increasingly preying on otters,
likely because fewer sea lions are available.
Sea lions decline along with their prey – fish.
Fish numbers are dropping, scientists
believe, not only because of overfishing, but
also because their food source – plankton –
is scarcer in warming ocean waters.
Monarch Butterflies
• Some butterfly populations have already
shifted north as the planet warms. For
others, the risk is even higher. Our bestknown butterfly, the monarch, has breeds
all over North America. Yet it depends on a
few critical spots on the continent for
winter habitat. Millions of eastern
monarchs migrate to high-altitude nyamel
fir trees in Mexico that are threatened by
weather extremes belived to be
accelerating under climate change.
Giant Panda
• About 1,600 giant pandas live in the wild in
China, where earlier surveys showed only
1,000. Yet immediate threats continue:
poaching, habitat loss and fragmentation, as
human populations press into its forest habitat.
Eons ago, the panda was carnivorous, but it
now subsists almost entirely on vast quantities
of bamboo. That plant’s restricted and
fragmented range further imperils the panda,
which is one of the world’s best-known and
best-loved endangered species.
Ocelot
• Only 50-100 endangered ocelots remain
in the U.S., most along a 50-mile stretch
of South Texas coast. After losing 95% of
their habitat to brush clearing, these cats
are further imperiled by climate change.
Rising seas could cover most remaining
habitat and migration north is not an
option – no habitat remains there. An
additional climate change concern is
increasing weather extremes – droughts,
flooding and severe hurricanes, any of
which could wipe out the tiny population.
White Rhinoceros
• The world’s second largest mammal, the
white rhinoceros of Africa, is named not
for its color but probably for the mud in
which it wallows. Two subspecies exist.
Once close to extinction, the southern
population Is now relatively secure, but
its critically-endangered northern
counterpart numbers only about 30.
Poaching threatens both subspecies.
Leatherback Turtle
• Largest of the sea turtles, weighing up to
2,000 pounds, the leatherback begins life
as a tiny hatchling making its way from a
sandy beach to sea. Few survive to
reproduce, and only nesting females ever
return to land. Most sea turtles are
believed to nest on their natal beach – if
it’s still there. Rising sea levels and more
intense storms resulting from climate
change further imperil already-declining
sea turtles.
African Elephant
• An icon of Africa’s rich wildlife, the
elephant, faces a new challenge: loss of
its forest and savannah habitat to
climate change. Already endangered by
poaching and habitat losses to human
population increases, the African
elephant is expected to lose yet more
habitat in a warmer, drier Africa. As the
planet’s largest mammal, the African
elephant needs vast lands to supply its
plant-based diet.
Pika
• Though they look like mice, pikas are
actually small-eared kin of rabbits. They
live on rocky slopes at alpine and subalpine altitudes, where they scurry about
to the delight of hikers. This remote habitat
once provided security for pikas, but their
survival is now imperiled by climate
change. As the world becomes warmer,
biologists are finding that some U.S.
populations are moving to higher altitudes
and others are disappearing entirely.
Snow Leopard
• The beautiful and elusive snow leopard is
imperiled by increasing poaching and
conflicts with human land uses in its high
altitude homes in Central Asia. Now a new
threat has appeared in these mountains:
climate change. As the snow line recedes,
imperiled snow leopards – which are
adapted to hunt on snowy terrain – move
higher, where vegetation is scarcer. Fewer
plants mean less prey, and ultimately
fewer snow leopards.
Giant Bronze Gecko
• The Giant Bronze Gecko is endemic to
the Seychelles islands of Silhouette and
Praslin. In 2005, the total population was
estimated at 3,184-3,594 animals.
Currently listed as Vulnerable because
the species has a very restricted range
and it will be vulnerable to any
degradation of its habitat, for example
through the spread of invasive species.
Oceanic Whitetip Shark
• The Oceanic Whitetip Shark is one of the most
widespread of shark species, ranging across
entire oceans in tropical and subtropical waters.
The Vulnerable species is subject to fishing
pressure virtually throughout its range. It is caught
in large numbers as a bycatch in open sea
fisheries, with longlines, probably gillnets,
handlines and occasionally open sea and even
bottom trawls. Its large fins are highly prized in
international trade although the carcass is often
discarded. Fishery pressure is likely to persist if
not increase in future.
Manta Ray
• The Manta Ray is has a wide range in tropical
and semi-tropical shelf waters. Only a few
directed fisheries exist. Recent demand for
branchial filaments, which are dried and
exported for the Asian medicinal market, has
resulted in dramatic increases in fishing
pressure for mobulids, including mantas,
throughout South East Asia and Eastern Africa.
Population declines have been observed in the
Philippines, Mexico, Sri Lanka/India, Indonesia.
Anthropogenic pressures (i.e., direct/indirect
fisheries, pollution, and exploitation of coastal
environments) in areas supporting critical
habitats like breeding, birthing, and nursery
grounds threaten the species.
Glaciers
• Two centuries ago, ice blanketed Glacier
Bay, Alaska. Renowned naturalist John Muir
wrote in 1879, "I saw the berg-filled expanse
of the bay… and the imposing fronts of five
huge glaciers. … A solitude of ice and snow
and newborn rocks, dim, dreary, mysterious."
The retreat of non-tidewater glaciers in
Glacier Bay is related, scientists believe, to
climate change. Satellite images help NASA
study changes in the area. (credit:
NASA/Goddard Space Flight Center)
More on Glaciers
• Worldwide, glaciers are shrinking. As
melting accelerates, we lose more than
scenic vistas: For millennia, drinking water
and agriculture for millions of people and
critical ecosystems have been supplied by
glaciers melting at sustainable rates. For
decades, arctic ice fields have safely
locked up long-living pollutants brought by
winds from distand, industrialized areas. In
a warmer world, coastal regions are likely
to experience catastrophic flooding and
erosion from rising ocean levels.
Rising Sea Level
• A "fifty-year" flood deluged this
Hoboken, NJ underground train
station when the 1992 Nor’easter
storm hit. This kind of flooding will
occur much more frequently as rising
sea levels generate higher storm
surges and more extreme weather
events cause more floods of this
magnitude. (credit: FEMA/USACE)
The Everglades
• Environmentalist and author Marjory
Stoneman Douglas wrote in 1947,
"There are no other Everglades in the
world. They are, they always have
been, one of the unique regions of the
Earth; remote, never wholly known."
But scientists today recognize this
delicate, low-lying ecosystem -- and all
of southern Florida -- is threatened by
sea level rise. (credit: EPA)
Eroding Coastlines
• Global warming causes a rise in sea levels,
which erode coastlines and destroy
ecosystems and habitats for people and
animals. According to the EPA, sea levels
along the Florida coast are already rising at
rates 6-10 times faster than those over the
past three millennia, and are likely to rise
as much as 20 inches above their 1990
levels by the year 2100. (credit: Army
Corps of Engineers)
Beaches
• Global warming is also contributing to
beach erosion, which puts a huge
drain on local, state, and federal
government resources to reconstruct
some of the country's favorite vacation
spots such as Savannah, Georgia's
Tybee Island pictured here. (credit:
Army Corps of Engineers)
Increasing Insect-borne Diseases
• As the Earth heats up, the risk of insectborne diseases such as malaria and
Lyme disease, is expected to rise. This
mosquito which carries dengue fever,
for example, may be able to spread into
more habitats, breed in higher numbers,
and thus become a greater risk to a
more widespread human population.
(credit: Centers for Disease Control and
Prevention)
Droughts
• Droughts also make vegetation more
vulnerable to pest infestations and disease.
As the climate heats up, droughts are
expected to become more frequent and
severe in some locations. During a drought
in the summer of 2000 Lake Michigan water
levels receded considerably. Social impacts
of such severe conditions include reduced
food availability, compromised water quality,
and conflicts around water rights. (Credit:
Jaye Lunsford, courtesy of U. S. Geological
Survey)
Forest Fires
• Sustained drought makes wildfires
more likely. This blaze in June 2002,
known as the Hayman Fire, was
Colorado’s biggest wildfire ever.
Management practices and
development in addition to drought
contribute to the severity of wildfires.
(credit: Michael Rieger/FEMA)
Forest Fires (continued)
• Titanic forest fires such as the
one that ravaged Mongolia in
April 1996 add large amounts of
carbon dioxide to the
atmosphere, thus contributing to
global warming. (credit: NASA
Johnson Space Center)
Tropical Forests
• In the tropics, "slash-and-burn"
land clearing practices -- an
unfortunate, common method of
clearing land for farms or cattle
ranches -- can trigger large fires
during extended droughts, as
pictured here in Brazil during the
1970s.
Why Tropical Forests are Better than
Alternate Land uses such as cattle-ranching
• It filters more pollution from the air.
• It produces more oxygen.
• It stores more carbon, reducing the
amount in the atmosphere.
• It has greater biological diversity –
contains 50% of the plants species on
earth, many which may have much to offer
us some day.
• It reduces precipitation runoff more,
thereby reducing flooding.
Coral Reefs
• Ocean temperatures have been
warming over the last century, and
water that is only 2 to 3° F warmer
than normal has been linked to the
bleaching of coral reefs. Other factors
which may contribute to bleaching
include nutrient and sediment runoff
from waterways, coastal development,
dynamiting of reefs and natural storm
damage.
More on Coral Reefs
• Biologically rich and complex, coral reefs
are found in tropical waters worldwide.
Already at risk from pollution, over-fishing,
destructive fishing practices, and careless
fishing practices, these colorful
ecosystems now struggle to survive as
ocean temperatures rise. Warmer water
causes corals to release the algae that
provide much of their food. Bleached coral
reefs are the white ghosts that remain.
The Earth
• When astronauts first viewed Earth from
space a few decades ago, they were
awed not only by the beauty of our
planet, but its vulnerability. Today we
know far more about the perils to our
only home. Climate change has vast
potential for planet-wide harm, not only
for humanpopulations, but also plants,
animals and the habitats upon which
they depend.