| Dear
EarthTalk: Recent NASA photos showed the opening
of the Northwest Passage and that a third of the Arctic’s
sea ice has melted in recent years. Are sea levels already
starting to rise accordingly, and if so what effects is
this having?
-- Dudley Robinson, Ireland
| |
An
iceberg off Antarctica. According to Robin Bell of
Columbia University‚s Earth Institute, if the
West Antarctic ice sheet were to disappear, sea level
would rise almost 19 feet; the ice in the Greenland
ice sheet could add 24 feet to that; and the East
Antarctic ice sheet could add yet another 170 feet
to the level of the world‚s oceans.
© Getty Images |
Researchers
were astounded when, in the fall of 2007, they discovered
that the year-round ice pack in the Arctic Ocean had lost
some 20 percent of its mass in just two years, setting a
new record low since satellite imagery began documenting
the terrain in 1978. Without action to stave off climate
change, some scientists believe that, at that rate, all
of the year-round ice in the Arctic could be gone by as
early as 2030.
This
massive reduction has allowed an ice-free shipping lane
to open through the fabled Northwest Passage along northern
Canada, Alaska and Greenland. While the shipping industry—which
now has easy northern access between the Atlantic and Pacific
oceans—may be cheering this “natural”
development, scientists worry about the impact of the resulting
rise in sea levels around the world.
With
about a third of the world’s population—and
25 percent of Americans—living within 300 feet of
an ocean coastline, sea level rise is a big deal. According
to the Intergovernmental Panel on Climate Change, made up
of leading climate scientists, sea levels have risen some
3.1 millimeters per year since 1993.
The
World Wildlife Fund (WWF) reports that low-lying island
nations, especially in equatorial regions, have been hardest
hit by this phenomenon, and some are threatened with total
disappearance. Rising seas have already swallowed up two
uninhabited islands in the Central Pacific. On Samoa, thousands
of residents have moved to higher ground as shorelines have
retreated by as much as 160 feet. And islanders on Tuvalu
are scrambling to find new homes as salt water intrusion
has made their groundwater undrinkable while increasingly
strong hurricanes and ocean swells have devastated shoreline
structures.
WWF
says that rising seas throughout tropical and sub-tropical
regions of the world have inundated coastal ecosystems,
decimating local plant and wildlife populations. In Bangladesh
and Thailand, coastal mangrove forests—important buffers
against storms and tidal waves—are giving way to ocean
water.
Unfortunately,
even if we curb global warming emissions today, these problems
are likely to get worse before they get better. According
to marine geophysicist Robin Bell of Columbia University’s
Earth Institute, sea levels rise by about 1/16” for
every 150 cubic miles of ice that melts off one of the poles.
“That
may not sound like a lot, but consider the volume of ice
now locked up in the planet’s three greatest ice sheets,”
she writes in a recent issue of Scientific American. “If
the West Antarctic ice sheet were to disappear, sea level
would rise almost 19 feet; the ice in the Greenland ice
sheet could add 24 feet to that; and the East Antarctic
ice sheet could add yet another 170 feet to the level of
the world’s oceans: more than 213 feet in all.”
Bell underscores the severity of the situation by pointing
out that the 150-foot tall Statue of Liberty could be completely
submerged within a matter of decades.
CONTACTS:
Intergovernmental Panel on
Climate Change (IPCC); World
Wildlife Fund (WWF); Earth
Institute at Columbia University.
Dear
EarthTalk: What’s available now in lawnmowers
that are easier on the environment? My yard is too big for
one of those “reel” mowers, and I’m no
longer a spring chicken, so I have to buy something that
runs on more than human power. What’s out there?
-- Joel Klein, Albany, NY
| |
For
those ready to take the electric mower plunge, there
are many models now available from Black & Decker,
Craftsman, Homelite, Neuton, Remington and Worx. Pictured
here is Neuton's top of the line battery-powered CE
6.2 mower.
© Neuton Power |
According to
the U.S. Environmental Protection Agency (EPA), traditional
gas-powered lawnmowers are a public nuisance to say the
least. Using one of them for an hour generates as many volatile
organic compounds—dangerous airborne pollutants known
to exacerbate human respiratory and cardiovascular problems—as
driving a typical car for 350 miles. The EPA estimates that,
with some 54 million Americans mowing their lawns on a weekly
basis, gas lawnmower emissions account for as much as five
percent of the nation’s total air pollution. Beyond
that, homeowners spill some 17 million gallons of gasoline
every year just refueling their lawnmowers.
So what’s
a green-minded property owner to do about keeping the grass
down? Go electric, of course!
Electric mowers,
which either plug into a wall outlet via a long cord or
run on batteries charged up from the grid, create no exhaust
emissions and run much cleaner than their gas-powered counterparts.
They also need less maintenance, with no spark plugs or
belts to worry about, and are easier to use, as they tend
to be smaller and come with push-button starters. The icing
on the cake might be the fact that electric mowers are cheaper
to run, using about as much electricity as an ordinary toaster.
Most electric mower owners spend about $5 a year on electricity
to keep their grass trimmed just right. The non-profit Electric
Power Research Institute reports that replacing half of
the 1.3 million or so gas mowers in the U.S. with electric
models would save the equivalent amount of emissions of
taking two million cars off the road.
But going electric
has some minor trade-offs. Electric mowers tend to cost
up to $150 more than their gas-powered counterparts, and
the plug-in varieties can only go 100 feet from the closest
outlet without an extension cord. And the cordless models
last only 30-60 minutes on a charge, depending on battery
size and type, though that’s plenty sufficient for
the average lawn (just remember to re-charge it in time
for the next mow).
And, of course,
just because electric mowers don’t consume fossil
fuels or spew emissions directly doesn’t mean they
are totally green-friendly. Most people derive their household
electricity from coal-fired power plants, the dirtiest of
all energy sources. Of course, running an electric mower
on electricity generated from clean and renewable sources
(solar, wind or hydro power) would be the greenest of all
possibilities, and those days may be upon us soon.
For those ready
to take the electric mower plunge, the Greener Choices website,
a project of Consumer Reports, gives high marks to Black
& Decker’s corded ($230) and cordless ($400) models
for their efficiency, reliability and ease-of-use. Corded
models from Worx and Homelite (both around $200) also fared
well, along with cordless offerings from Craftsman, Homelite,
Remington and Neuton ($300-450).
CONTACTS:
Black & Decker;
Remington;
Homelite;
Worx;
Neuton;
Greener
Choices. |
A
SYNDICATED COLUMN ONLY ON AMERICAJR.COM
|
