| Dear
EarthTalk: Are the recent cyclones and droughts
in Australia and elsewhere more evidence of global warming?
--Billy Hulkower, Los Angeles, CA
Scientists
can’t blame individual storms or droughts on climate
change, but many believe that human-induced global warming
is increasing the severity and frequency of such weather “anomalies.”
Indeed, on February 2, 2007 scientists with the Intergovernmental
Panel on Climate Change (IPCC) released a long-awaited 21-page
report confirming “with 90 percent certainty”
that increases in man-made greenhouse gases since the mid-20th
century are raising the planet’s temperature and destabilizing
the climate.
Besides
hurricanes like Katrina that have affected the northern hemisphere,
a number of high-impact tropical cyclones and typhoons have
occurred around the world in just the last few years, with
Australia’s mammoth Cyclone Larry topping the list in
terms of intensity. That March 2006 storm battered the northern
Queensland coast with 180 mile-per-hour winds, causing hundreds
of millions of dollars in property damage and virtually wiping
out Australia’s banana crop. Thanks to Australia’s
top-notch weather forecasting and emergency preparedness,
however, unlike Katrina, Larry claimed no human lives.
Meanwhile,
higher global temperatures have at least worsened if not outright
caused drought conditions around the world, and Australia
has been no exception. A 2003 report by the Australia chapter
of the World Wildlife Fund found global warming to be a key
factor in the severity of the country’s 2002 drought,
one of four especially harsh droughts in just the last 50
years. The 2002 drought, which many scientists consider to
be still in effect, was particularly memorable as Australians
endured higher daytime temperatures than had ever been recorded
during any March-November winter season. Besides causing countless
bush fires in the Australian Outback, the drought has led
to a significant drop in agricultural production, causing
hundreds of millions of dollars in economic losses, according
to government data.
An
original 1997 signatory to the landmark Kyoto Protocol calling
for reduced greenhouse gas emissions, Australia’s government
nevertheless has refused to ratify and adhere to the terms
of the treaty. Prime Minister John Howard has taken a position
similar to that of U.S. President George W. Bush, who considers
the terms of Kyoto bad for industry.
But
just because Australia hasn’t ratified Kyoto doesn’t
mean it has refused to acknowledge the potential environmental
impacts of global warming. The country has pledged $300 million
over three years to implement various strategies to reduce
greenhouse gas emissions. It has also signed onto the Asia-Pacific
Partnership on Clean Development and Climate, an agreement
with India, Japan, China, South Korea and the U.S. to develop
technology that helps reduce greenhouse gas emissions. Whether
such an agreement has enough teeth to take a bite out of global
warming is anybody’s guess, but it and other endeavors
to fight global warming will undoubtedly pick up momentum
with the release of the landmark IPPC report.
CONTACTS:
World Wildlife Fund Australia
drought report; Intergovernmental
Panel on Climate Change, ; Asia-Pacific
Partnership on Clean Development and Climate
PHOTO
COURTESY OF GETTY IMAGES
Food
containers like these, along with many other kinds of plastics,
may soon be made mostly from corn and other plant-based materials.
Dear EarthTalk:
Dairy products like yogurt always seem to come in packages
of low recyclabilty (labeled “5,” which our town
won’t take). Why aren’t these containers more
recyclable? And isn’t there a more eco-friendly container
these companies could use?
-- John Marble, Portland, ME
The ability to
recycle a plastic item rests with many factors, including
its material, its usability in new products once it has been
broken down into its original components, and whether or not
a market is in place that can facilitate transactions of the
recycled materials from sellers to buyers.
Recycling polypropylene
(designated with a “5”), the material used in
many food containers, is technically possible. The challenge
is in separating it from other plastics, including its own
many variations, once it arrives at the waste station and
beyond. Because of the difficulty and expense of sorting,
collecting, cleaning and reprocessing plastics of all kinds,
in many places it is only economically viable to recycle a
few select types. These usually include polyethylene terephthalate
(PETE, designated with a “1”), high-density polyethylene
(HDPE, “2”), and sometimes polyvinyl chloride
(PVC, “3”).
According to the
Society of the Plastics Industry, polypropylene is a “thermoplastic
polymer,” meaning that it has the density and resins
that give it a high melting point, enabling it to tolerate
hot liquid without breaking down. As such, it is used in a
wide range of food packaging applications in which the product
initially goes into the container hot or is later microwave
heated in the container. It is also used to make bottle caps,
computer disks, straws and film packaging. Its toughness,
strength, ability to be a barrier to moisture, and resistance
to grease, oil and chemicals also make it a very attractive
material for many uses.
Environmentally
friendly alternatives to polypropylene and other plastics
are beginning to be developed, however. NatureWorks, a division
of Cargill, has developed a corn-based plastic called polylactic
acid (PLA). While it looks and functions like other plastics
PLA is fully biodegradable, given that it is derived from
plant-based materials. Whether it is composted or landfilled,
it will biodegrade into its constituent organic parts, though
there are debates as to how long that process takes.
Another pioneering
company is Massachusetts-based Metabolix, which has partnered
with corporate giant, Archer Daniels Midland, to make corn
plastics that the company claims will “biodegrade benignly
in a wide range of environments, including marine and wetlands.”
A handful of natural
foods companies and retailers, including Newman’s Own
Organics, Del Monte Fresh Produce and Wild Oats Markets, are
already using corn plastic for some of their packaging, though
not yet to replace heat-resistant polypropylene. Analysts
expect such plant-based alternatives to come on stronger and
stronger in the days ahead as petroleum becomes more expensive
and more politically unstable. Even Coca-Cola has started
experimenting with replacing its traditional plastic soda
bottles with a corn-based alternative. And last October, as
part of its “green” overhaul, Wal-Mart announced
it would replace 114 million plastic produce containers a
year with PLA varieties, sparing about 800,000 barrels of
oil annually.
CONTACTS:
NatureWorks;
Metabolix; The
Society of the Plastics Industry |
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