| Dear
EarthTalk: The U.S. got socked with several
major storms this past winter. Local weather reports never
mentioned this as odd. But is it a sign of global warming?
-- R.A. Forbes, via e-mail
| |
We
must keep in mind the difference between climate and
weather. Climate is the average of weather over at
least three decades, which means that specific storms
or even individual snowy winters, let alone other
types of extreme weather, cannot be considered evidence
of either the existence or nonexistence of global
warming.
© Tanya Liu, courtesy Flickr |
Weather
patterns and trends are notoriously unpredictable, varying
due to a great many different inputs. While it’s true
that snowier, stormier winters could be the result of global
warming, many meteorologists believe that El Nino—a
climate pattern involving warmer-than-usual sea temperatures
across the tropical Pacific that affects weather all over
the globe—is mainly to blame for this past winter’s
ongoing white misery.
According
to Joe Bastardi, a meteorologist with the Pennsylvania-based
AccuWeather forecasting service, the current El Nino—they
occur once every three to seven years—has been “very
strong, prompting many major blizzards for the mid-Atlantic
region.” By altering the intensity of the atmospheric
jet stream, El Nino can force cold air from Northern Canada
to push down into the United States, converting the moisture
in clouds into falling snow as temperatures drop.
Bastardi
believes that El Nino is exacerbating an already ongoing
trend of cooling in the Pacific that is part of natural
cyclical patterns of heating and cooling unrelated to global
warming. “When you get an El Niño with a cold
Pacific, you get crazy winters in the East,” he told
National Geographic News.
Of
course, global warming could also be playing a role, according
to Amanda Staudt, a climate scientist with the National
Wildlife Federation. “It’s hard to determine
global warming’s effect on any particular storm, but
it’s highly unusual to have these really large winter
storms in one winter,” she says. “Oddball winter
weather is yet another sign of how uncontrolled carbon pollution
amounts to an unchecked experiment on people and nature.”
Staudt reports that warmer temperatures cause more water
to evaporate off the oceans and settle in clouds in the
sky, where it eventually falls back to the Earth’s
surface as rain or, if temperatures are low enough, snow.
The
same types of atmospheric conditions have conspired at times
to dump multiple feet of snow in the Great Lakes of the
Midwest at unseasonable times. A 2003 study in the Journal
of Climate found that as global temperatures have risen;
the winter ice cover over the Great Lakes has decreased,
leading in turn to more moisture in the atmosphere and snowier
winters throughout the region. This is sometimes referred
to as the “lake effect.”
Whether
or not this past winter’s storms were exacerbated
by global warming, scientists maintain that we must keep
in mind the difference between climate and weather. According
to the National Oceanic and Atmospheric Administration (NOAA),
climate is the average of weather over at least three decades,
which means that specific storms or even individual snowy
winters, let alone other types of extreme weather, cannot
be considered evidence of either the existence or nonexistence
of global warming.
CONTACTS:
Accuweather;
National Wildlife Federation,
Journal of
Climate; National Oceanic
and Atmospheric Administration (NOAA).
Dear
EarthTalk: I‘ve been hearing about the
popularity of milk sold in bags (as opposed to plastic or
cardboard cartons) in India, Europe and Canada. What are
the environmental advantages to milk in bags, and do you
think it will catch on in the U.S.? And what other options
are out there for milk drinkers trying to be green?
-- Paul Howe, San Francisco, CA
| |
Plastic
milk bags are popular in many parts of Europe, Latin
America and India and are catching on in Canada, South
Africa and China. They use 75 percent less plastic
than similar capacity plastic jugs, are made of easily
recycled high-density polyethylene, and can be rinsed
out and tossed in with other recycling. Pictured:
an Israeli plastic milk bag.
© Ilan Costica, Wikipedia |
It‘s true
that plastic milk bags—not the cartons or jugs we
are used to here in the U.S.—are de rigueur in many
parts of Europe, Latin America and India and are catching
on fast in Canada, South Africa, China and elsewhere. They
typically hold a liter of milk and are sold in three-packs.
Most people snip off a corner of the milk bag and keep it
upright in a pitcher in the fridge. When the last drop has
been used up, the bags, which are made out of easily recycled
high-density polyethylene, can be rinsed out and tossed
in with other recycling. Best of all, they use 75 percent
less plastic than similar capacity plastic milk jugs.
The fact that
milk bags are easy to recycle and use much less plastic
(and as such are inexpensive) may be a big part of the reason
for their popularity all over the world. They are more popular
than ever in Great Britain today amid concerns that plastic
milk jugs there are not being recycled at adequate levels.
At least two of the UK‘s largest grocery chains have
switched over to milk bags in the last two years.
Of course, detractors
point out that milk bags are not as sturdy as plastic jugs—they
can puncture or burst if too much pressure is applied. Also,
they do not stand upright like harder containers and cannot
be sealed once snipped open—and are thus more prone
to spilling. Perhaps for these reasons, milk bags are losing
market share in many regions of the former Soviet bloc,
where they were for years the most common packaging for
milk. Some analysts cite the so-called “lower shelf
appeal” of milk bags as the reason, which might have
something to do with why U.S. supermarkets haven‘t
yet been eager to embrace them.
Of course, paper/cardboard
(half-gallon) milk containers are also relatively friendly
to the environment, especially if the empty boxes are worked
into compost either at the residential or municipal level,
or rinsed well and recycled. They tend to be more expensive
than plastic jugs, though, as they cost more to make. Several
companies are working on ways to employ recycled paper and
cardboard into larger milk jugs while keeping costs comparable
to inexpensive plastic jugs. And while most of us no longer
employ milk delivery services to our homes, the glass bottles
that they use (yes they still exist!)—and take back
for reuse—may be the ultimate in eco-friendly milk
storage, although driving the milk around and washing all
the glass bottles are not the most eco-friendly activities.
Perhaps the modern-day
version of the milkman is the herd share, whereby regular
folks contribute annually or monthly to a local dairy farm
in exchange for a gallon of milk fresh from the cow every
week. Many of the herd shares offered these days feature
organic milk from grass-fed cows, giving eco-conscious consumers
a way to help keep small farmers alive while enjoying milk
they know is safe and healthy. To find a herd share to join
in your area, check out the Local Chapters website page
of the Weston A. Price Foundation, a charity that works
to disseminate the research of whole foods nutrition pioneer
Dr. Weston Price.
CONTACTS:
Weston
A. Price Foundation; Farm-to-Consumer
Legal Defense Fund. |
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