| Dear
EarthTalk: I’ve heard about the die-off
of coral reefs due to global warming. I’ve also read
that coral reefs themselves store carbon dioxide (CO2),
one of the main global warming gases. So if coral reefs
are dying out, isn’t that a double whammy that increases
the CO2 in the atmosphere?
-- Tom Ozzello, Maplewood, MN
According
to marine scientists, the world’s coral reefs—those
underwater repositories for biodiversity that play host
to some 25 percent of all marine life—are in big trouble
as a result of global warming. Data collected by the international
environmental group WWF (formerly World Wildlife Fund) show
that 20 percent of the world’s coral reefs have been
effectively destroyed and show no immediate sign of recovery,
while about 50 percent of remaining reefs are under imminent
or long-term threat of collapse.
Most
scientists now agree that global warming is not a natural
phenomenon but a direct result of the continual release
of excessive amounts of CO2 and other “greenhouse”
gases into the atmosphere by human industrial and transportation
activity. And the small but prolonged rises in ocean temperature
that result cause coral colonies to expel the symbiotic
food-producing algae that sustain them. This process is
called “bleaching,” because it turns the reefs
white as they die.
But
researchers working with the Coral Reef Alliance have found
that while coral reefs do store CO2 as part of photosynthesis,
they tend to release most of it back into the ocean (so
they are not what are known as “carbon sinks”).
As such, the release of CO2 from dying coral reefs is not
a major concern.
Of
course, the ocean itself is a large carbon sink, storing
about a quarter of what would otherwise end up in the atmosphere.
Landmasses (and their plants) soak up another quarter of
all the CO2 emanating from the Earth’s surface, while
the rest rises up into the atmosphere where it can wreak
havoc with our climate.
Recent
findings indicate that the Antarctic Ocean is getting less
efficient at storing CO2, and this raises serious questions
about the ability of our oceans to handle everything we
throw at them. The study’s authors fear that “such
weakening of one of the Earth’s major carbon dioxide
sinks will lead to higher levels of atmospheric carbon dioxide
in the long-term.”
Not
everyone is forecasting gloom and doom. Some Australian
researchers believe that coral reefs around the world could
expand in size by up to a third due to increased ocean warming.
“Our finding stands in stark contrast to previous
predictions that coral reef growth will suffer large, potentially
catastrophic, decreases in the future,” says University
of New South Wales oceanographer Ben McNeil, who led the
controversial 2004 study that was published in the peer-reviewed
scientific journal, Geophysical Research Letters. “Our
analysis suggests that ocean warming will foster considerably
faster future rates of coral reef growth that will eventually
exceed pre-industrial rates by as much as 35 per cent by
2100,” he adds.
In
spite of such theories, the majority of marine scientists
remain pessimistic about the future of coral reefs in a
warmer world. One can only hope that the optimists are right.
CONTACTS:
WWF;
Coral
Reef Alliance; “Coral
reefs may grow with global warming,” New Scientist.
Dear
EarthTalk: Short of buying a new hybrid or
other “green” car, are there ways I can make
my existing vehicle more eco-friendly? I bought my car recently
and am not quite ready to give it up.
-- Bettie Hilliker, Lansing, MI
Choice of vehicle
may well be the biggest factor in determining the environmental
impact of your automobile-based travels. But a considerable
amount of energy is used—and pollutants emitted—in
the production of any new vehicle, including hybrids and
other more fuel-efficient options. As a result, many environmentalists
believe that practicing good driving habits and performing
adequate maintenance on an older car are probably better
options for the environment than causing the production
of a new vehicle.
According to
the website GreenerCars.org, there are many ways to green
up one’s driving habits. Obeying speed limits, utilizing
cruise control and avoiding jackrabbit starts will maximize
fuel economy and minimize tailpipe emissions while also
preventing unnecessary wear-and-tear. Staying off roads
during rush hours is also advisable, as stop-and-go driving
burns excess gasoline and promotes smog. Opening vents and
windows to cool off instead of using the air conditioner,
an inherently inefficient appliance that consumes more fuel
and leads to more emissions, is also good advice.
Drivers can also
help minimize their environmental impact by keeping their
cars well maintained. According to GreenerCars.org, getting
regular tune-ups—where a qualified mechanic changes
fluids and checks for and corrects problems such as worn
spark plugs, under inflated tires, dragging brakes, misaligned
wheels and clogged filters—can significantly improve
fuel economy and minimize harmful emissions. GreenerCars.org
also recommends seeking out low-rolling-resistance (LRR)
replacement tires, which are specifically designed to improve
a vehicle’s fuel economy, when the original ones wear
out.
Beyond regular
maintenance, a handful of small companies now sell green-friendly
fuel additives that purport to increase fuel efficiency
while reducing emissions. Such products—including
Bluestar Environmental’s Omstar D-1280X gas additive
and Suntec Bio-Energy’s diesel additive—are
normally targeted at fleets of vehicles, but individuals
are free to use them as well. Owners beware, though: Use
of such products could invalidate automakers’ warranties,
so read the fine print in your owner’s manual before
pouring anything out-of-the-ordinary into your fuel tank.
Of course, getting
out of your car altogether—or most of the time—is
a far greener choice than driving even a well-maintained
new or old car conscientiously. Some employers now offer
federally-subsidized “commuter choice” incentives
whereby workers can derive financial benefits by telecommuting
(working from home), or by walking, biking, using public
transit or carpooling to and from the office.
Another option
is to join a car sharing service like Zipcar or Flexcar,
whereby you pay a modest monthly membership fee and can
then rent cars parked nearby by the hour only when needed.
The companies operate on both U.S. coasts, as well as in
major Midwestern and Canadian cities.
CONTACTS:
GreenerCars.org
“Green Driving Tips,”; Bluestar
Environmental ; Suntec
Bio-Energy; Zipcar;
Flexcar. |
