Slowing cargo ships cuts pollution near ports by more than half, study
finds.
http://www.environmentalhealthnews.org/ehs/news/2012/ship-speeds
Slowing cargo vessels near coastlines by 10 to 15 miles per hour could
dramatically cut ships’ air pollution, according to a new study. But
only a few U.S. ports have initiated such efforts. A speed limit of 14
mph, down from the current cruising speeds of 25 to 29 mph, would cut
nitrogen oxides – a main ingredient of smog – by 55 percent and soot
by almost 70 percent. It also would reduce carbon dioxide – a potent
greenhouse gas and key contributor to climate change – by 60 percent.
With 100,000 ships carrying 90 percent of the world’s cargo, air
pollution is a heavy burden for people living near ports, so slowing
ships could improve their health, researchers say.
By Brett Israel
Staff writer
Environmental Health News
Nov. 19, 2012
Slowing cargo vessels near coastlines by 10 to 15 miles per hour could
dramatically cut ships’ air pollution, according to a new study. But
only a few U.S. ports have initiated such efforts.
A speed limit of 14 mph, down from the current cruising speeds of 25
to 29 mph, would cut nitrogen oxides – a main ingredient of smog – by
55 percent and soot by almost 70 percent, according to the University
of California, Riverside study. It also would reduce carbon dioxide –
a potent greenhouse gas and key contributor to climate change – by 60
percent.
With 100,000 ships carrying 90 percent of the world’s cargo, air
pollution is a heavy burden for people living near ports, so slowing
ships could improve their health, researchers say.
In the study, the ships traveled at speeds already used at the ports
of Los Angeles/Long Beach and New York-New Jersey as part of voluntary
programs.
“Vessel speed reduction does significantly reduce emissions, and
that's why we have had a vessel speed reduction program in place at
our port for several years,” said Arley Baker, a spokesperson for the
Port of Los Angeles. “It’s both a feasible and practical way to reduce
vessel emissions.”
But setting a speed limit on cargo ships has been an elusive goal for
port cities because shipping traffic is regulated internationally.
All ocean-going vessels, when they are within 10 nautical miles of a
U.S. port, must slow down, to typically 14 mph. The voluntary programs
in Los Angeles/Long Beach and New York-New Jersey slow them farther
out, up to 40 miles offshore.
A ship’s fuel consumption and emissions increase exponentially with
speed, so burning low-grade oil at traditional cruising speeds emits
more air pollution than slower ships, according to the study, led by
environmental engineer David Cocker.
"Speed reductions, which are known to reduce emissions, would need to
be maintained over a very long-term period in order to produce
regional air quality benefits," said James Corbett, a professor of
marine policy at the University of Delaware, who has studied the
impact of the shipping industry on human health. Corbett was not
involved with the new study.
The new study measured the emissions of two container vessels
traveling between California's Ports of Los Angeles and Long Beach and
the Port of Oakland. Emissions were measured near the ports and in
international waters.
In international waters, ships burn heavy fuel oil. As it burns, large
amounts of particulate matter, sulfur oxides and nitrogen oxides are
released.
Studies worldwide have linked particulate matter – soot – to deaths
from respiratory disease and heart attacks. Particulates specifically
from ocean-going vessels have been linked to an increased number of
premature deaths, according to a 2007 study by Corbett published in
the journal Environmental Science and Technology.
In addition, the shipping industry is responsible for 3 percent of the
world's carbon dioxide emissions, according to the International
Maritime Organization, a United Nations agency responsible for marine
safety and pollution. Shipping emissions are expected to grow 2 to 3
percent every year over the next three decades [PDF] as shipping
traffic grows, according to the IMO.
The industry has dodged tax strategies and international treaties,
such as the Kyoto Protocol. The International Maritime Organization
has failed to set a cap on greenhouse gas emissions at international
meetings in previous years. Under the World Port Climate Initiative,
some of the world’s leading ports have committed to reducing their
greenhouse gas emissions.
Some states and local pollution agencies are stepping in. California
has banned ships from burning dirty kinds of fuel, and is rolling out
other clean port initiatives.
Since 2001, the Ports of Los Angeles and Long Beach – the nation’s two
busiest shipping ports – have offered financial incentives to shippers
that voluntarily reduce their speeds to 14 mph. Baker said it has led
to 90 percent compliance.
Smog-causing nitrogen oxides from the Los Angeles port’s ships
declined 30 percent between 2005 and 2011, while particulate matter
decreased about 70 percent. Carbon dioxide was not reported.
"I think it has been quite effective," said Sam Atwood of the South
Coast Regional Air Quality Management District, the local air
pollution agency that monitors the side-by-side ports of Los Angeles
and Long Beach.
In August, the Port of New York and New Jersey approved several
initiatives to reduce emissions, including a voluntary speed reduction
program similar to the Ports of Los Angeles and Long Beach.
Ocean-going vessels that reduce their speed to no more than 10 knots
(11.5 mph) starting 20 nautical miles from the entrance to the New
York-New Jersey harbor earn financial incentives and recognition.
Shippers might not want to slow down because “hours lost in transit
can cost carriers and their shipping customers dearly," said Aaron
Ellis of the American Association of Port Authorities.
An industry group, the U.S. Shippers Association, noted that there are
other ways to clean up the industry.
“Speed limits are only one, and not necessarily the most effective,
way to reduce greenhouse gas emissions. Vessel owners should be
encouraged to implement as many options as possible to meet and exceed
emission reduction standards,” said Beverly Altimore, executive
director of the U.S. Shippers Association.
In Southern California, one other solution has been to supply
shore-side power so that ships can plug into the electric grid while
docked rather than idling their engines, Atwood said.
The authors of the new study warned that emissions reductions near
ports could be negated if the ships travel faster than normal cruising
speeds outside of the slow zones.
“It is important to note that vessels speeding up to make up for lost
time at the slower speeds in the [vessel speed reduction] zone could
have an overall increase in CO2 and other emissions,” the researchers
wrote.
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"Whatever is inconsistent with the facts must be discarded
or revised." -- Dr. Carl Sagan