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The
North Pole moves as ice sheets melt
The
North Pole’s surprise trip toward Greenland is due to Earth's
rapidly melting ice sheets, a new study finds.
15
May, 2013
The
distribution of mass across the planet determines the position of
Earth's poles. Because Earth is a bit egg-shaped, the North Pole is
always slightly off-center. It's also been slowly drifting south,
responding to long-term changes since the last Ice Age, as the
enormous ice sheets that once covered large swaths of the planet
melted and parts of the Earth rebounded from the lost weight.
But
in 2005, the pole suddenly started making a beeline east for
Greenland, moving a few centimeters eastward each year. The cause?
Rapid melting of the Greenland Ice Sheet, finds a study published
Monday in the journal Geophysical Research Letters. Ice loss and the
associated sea-level rise account for more than 90 percent of the
polar shift, Nature News reported.
Melting
ice moves mass around by adding water to the oceans and lightening
the load on ice-covered crust. Although global ice melt plays a role
in the pole's shift, Greenland itself is the primary contributor to
the eastward movement, the researchers found. "Both of (those
factors) are contributing, but now we can say glacial melting in
Greenland produces an observable polar motion," said Clark
Wilson, a study co-author at the University of Texas, Austin.
The
change is small, dwarfed by the pole's broad wandering circles, which
are caused by Earth's bulging midriff (the 14-month Chandler wobble)
and an annual wobble related to seasonal shifts. However, "if
you remove those effects, you'll see a long-term drift," Wilson
told LiveScience.
Using
data from NASA's GRACE satellite, which measures Earth's gravity
field, the researchers tested whether Greenland's ice loss changed
the pole position. The data can track how water and ice shift across
the planet. "Mass is moving around all the time," Wilson
said.
Knowing
the precise location of the North Pole has become a critical part of
modern life. It's the foundation of GPS, which guides people with
mapping apps, as well as military systems and planes
A
little over 2 years ago the headlines were full of Climategate,
in which climate scientist were accused of fraud by the skeptics,
including over the melting of the Himalaya glaciers
Mount
Everest’s glaciers are melting
Climate
change is believed to be the reason why the Mount Everest glaciers
are melting, reducing the frozen layer around the mountain. NBC’s
Brian Williams reports.
Natural
Disasters Have Cost The Global Economy $2.5 Trillion Since 2000
Economic
losses from disasters since 2000 are in the range of $2.5 trillion, a
figure at least 50 per cent higher than previous international
estimates, according to a U.N. report released Wednesday.
15
May, 2013
The
U.N. Office for Disaster Risk Reduction warned in the 246-page report
that economic losses from floods, earthquakes and drought will
continue to escalate unless businesses take action to reduce their
exposure to disaster risks.
U.N.
Secretary-General Ban Ki-moon launched the report saying the review
of disaster losses in 56 countries clearly demonstrates that
“economic losses from disasters are out of control” and can only
be reduced in partnership with the private sector.
“Our
startling finding is that direct losses from floods, earthquakes and
drought have been underestimated by at least 50 per cent,” Ban
said. “So far this century, direct losses from disasters are in the
range of $2.5 trillion. This is unacceptable when we have the
knowledge to reduce the losses and benefit from the gains.”
For
too many years, the secretary-general said, financial markets have
placed greater value on short-term returns than on sustainability and
resilience, which in the long-term are far more attractive and can
save millions of dollars.
“In
the years ahead, trillions of dollars will be invested in
hazard-exposed regions,” Ban said. “If that money fails to
account for natural hazards and vulnerabilities, risk will increase.
Where such spending does address underlying risk factors, risk will
go down.”
The
report said recent major disasters such as Hurricane Sandy in 2012,
the 2011 floods in Thailand and the 2011 Japanese earthquake and
tsunami put a spotlight on the growing impact of disasters on the
private sector.
The
report says increasing globalization, the search for lower costs and
higher productivity, and quick delivery “are driving business into
hazard-prone locations with little or no consideration of the
consequences on global supply chains.”
For
example, it said Toyota lost $1.2 billion in product revenue from the
Japanese quake due to parts shortages that caused 150,000 fewer cars
to be manufactured in the United States and a 70 per cent reduction
in production in India and a 50 per cent reduction in China.
On
the other hand, Orion, which owns and operates one of the largest
electricity distribution networks in New Zealand, invested $6 million
in seismic protection that saved the company $65 million in the 2010
and 2011 earthquakes, the report said. And preventive investments by
fishermen in Mexico saved each individual entrepreneur US$35,000
during Hurricane Wilma in 2005, it said.
But
Margareta Wahlstrom, the U.N. special representative for disaster
risk reduction, said: “In a world of ongoing population growth,
rapid urbanization, climate change and an approach to investment that
continually discounts disaster risk, this increased potential for
future losses is of major concern.”
A
new global risk model developed by the U.N. office demonstrates that
average losses just from earthquake and cyclonic wind damage are
expected to be about $180 billion per year throughout this century —
and this figure doesn’t include damage from floods, landslides,
fires and storms, the report said.
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