http://www.panda.org/news_facts/newsroom/news/index.cfm?uNewsID=147341
Climate change to devastate or destroy penguin colonies
08 Oct 2008
Half to three-quarters of major Antarctic penguin colonies face
decline or disappearance if global temperatures are allowed to climb
by more than 2°C.
A new WWF report – 2°C is Too Much – shows that 50 per cent of the
iconic emperor penguins and 75 per cent of the Adélie penguins are
under threat.
Climate change models forecast that a 2°C temperature rise above pre-
industrial levels could be a reality in less than 40 years, producing
a strong reduction in the sea ice cover of the Southern Ocean which is
an essential nesting and feeding ground for Emperor and Adélie penguins.
A reduction in the sea ice will also have knock-on effects on the
abundance of krill, which is a vital food source for penguins.
Juan Casavelos, WWF Antarctica Climate Change Coordinator said:
“Penguins are very well adapted to living in the cold and extreme
conditions of Antarctica, so the continued increase in global
temperature and resulting loss of feeding areas and nesting zones for
their chicks has already led to notable reductions in their populations.
“If temperatures increase by another two degrees these icons of the
Antarctic will be seriously threatened.”
A rise in global average temperatures of 2°C is regarded as a
threshold level for unacceptable risks of catastrophic climate change.
Many recent climate models forecast likely temperatures rises in
excess of this.
Risks to penguins were underlined this week, when hundreds of penguins
were washed up on the Brazilian coast, thought to have been carried
north on warmer ocean currents.
Environmentalists say it is not known why the penguins became stranded
so far north, but suggest they could have been carried beyond their
usual range by a flow of warm water.
The penguins were airlifted home, using a huge airforce cargo plane.
Almost 400 that had strayed on to beaches, including Copacabana in Rio
de Janeiro, were saved.
Onlookers cheered as the young Magellanic penguins were set free on a
beach in southern Brazil and scampered into the ocean.
Experts hope a small group of older penguins released along with the
young ones will help to guide them south to Patagonia.
The stranded birds were among nearly 1,000 penguins that have washed
up on Brazil's north-eastern coast in recent months. The others have
either died or were not healthy enough to send back.
While the global average temperature rise currently sits at 0.74
degrees, temperatures are rising much more rapidly at the poles.
Temperature measurement in Antarctica has only been conducted with
some precision for about 50 years, with one station showing a rise of
2.5 °C in that time, indicating that Antarctic temperatures may be
rising at four times the global rate.
Rapid emissions reduction is the key to significantly reduce the
impacts of climate change in Antarctica.
WWF is calling for all nations to work together to agree on a new
global deal that will succeed the Kyoto Protocol and tackle climate
change beyond 2012.
This should include an obligation on developed countries to cut 25-40
per cent of their emissions by 2020 and 80-90 per cent by 2050,
compared to 1990 levels.
WWF also proposes the establishment of a network of marine protected
areas to reduce pressure on the species, and the implementation of
precautionary management measures that ensure the future of the krill
and finfish fisheries and all Southern Ocean species – including
penguins – that are dependant on them.
Juan Casavelos said: “The predicted threat to Emperor and Adélie
penguin populations is a clear incentive for the world to agree on a
set of measures to reduce global emissions.
“It is imperative that the international community analyses all
possible ways to limit climate change and improve the resilience of
the penguin population.”
http://assets.panda.org/downloads/wwf_climate_penguins_final_1.pdf
THE FATE OF ANTARCTIC PENGUINS WHEN EARTH’S TROPOSPHERIC TEMPERATURE
REACHES 2°C ABOVE PRE-INDUSTRIAL LEVELS
David Ainley1, Joellen Russell2 and Stephanie Jenouvrier3,
a collaboration with World Wildlife Fund
(with input from C. Barbraud4, W.R. Fraser5, G.L. Kooyman6, P. Lyver7,
and E. Woehler8
Abstract
We assessed how projected changes in the physical Southern Ocean will
alter population trajectories of the two pack-ice penguins of the
Antarctic, the Emperor (Aptenodytes forsteri) and Adélie (Pygoscelis
adeliae). Using a subset of IPCC AR4 climate model output for emission
scenario SRES A1B (doubling of CO2 from 360 and stabilizing at 720
after 2100), we identify the time period at which global temperature
will have increased by 2°C above pre-industrial levels. Using this
benchmark, rather than an arbitrary year, allowed removal of some of
the biases and uncertainties associated with the differing model
sensitivities.
We, then, for the Antarctic, considered criteria and identified a
subset of the “better” IPCC AR 4 climate model outputs. The “best”
four — GFDL-CM2.1, GFDL-CM2.0, MIROC3.2(hires), and MRI-CGCM2.3.2a —
were composited into an ENSEMBLE, which was then examined to look at
conditions at the year of 2°C warming. Care was taken to evaluate the
individual models that comprise the ENSEMBLE, as errors in different
models tend to cancel one another often leading to an unjustified
faith in the collective predictions. The ENSEMBLE output provided
indicators of sea-ice coverage, wind speeds, and air temperatures for
the Southern Ocean. These indicators of physical conditions were then
used to assess the impacts of a 2°C global warming on penguins’
habitat and ultimately their populations.
On the basis of the ENSEMBLE output, we concluded that 50% of Emperor
colonies (40% of population) and 75% of Adélie colonies (70% of
population) that currently exist at latitudes north of 70°S are in
jeopardy of marked decline or disappearance, largely because of severe
decreases in pack-ice coverage and, particularly for Emperors, ice
thickness as well (especially in the eastern Ross and Weddell seas).
Included are colonies on both sides of the northern Antarctic
Peninsula and in East Antarctica. To
some degree, Adélie Penguins would be able to colonize areas where
pack ice currently is too concentrated or where disintegrating ice
shelves will be exposing coastline and providing new breeding habitat.
However, this capacity will be importantly limited by the decreased
persistence of pack ice in areas north of the Antarctic Circle, as
this species seeks pack ice during winter where there is also
daylight.==============================www.birding-aus.org
birding-aus.blogspot.com
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