It is time to crack down on the emissions and destructive
development caused by vast container vessels that pollute the air and seas,
write Zheng Wan and colleagues (Zheng Wan, Mo Zhu, Shun Chen& Daniel
Sperling).
On
26 April 1956, US entrepreneur Malcom McLean watched a converted oil tanker
leave Port Newark in New Jersey carrying 58 of his inventions: the modular
shipping container. By 2015, the largest container ship in the world, with a
deck the area of 3.5 soccer fields, could carry about 20,000 of the units.
Ever-bigger
container ships carry 90% of global consumer goods such as clothes and food
(non-bulk cargo)1. The seaborne container trade has grown from 100 million
tonnes in 1980 to about 1.6 billion tonnes in 2014. Standardized 20-foot
(6-metre) containers are moved using automated systems that connect seaports,
airports and train stations2. Bigger ships carry more containers, ideally
consuming less oil and releasing fewer pollutants for each unit of goods
carried.
Nonetheless,
the human and environmental costs of shipping are vast. Low-grade marine fuel
oil contains 3,500 times more sulfur than road diesel. Large ships pollute the
air in hub ports, accounting for one-third to half of airborne pollutants in
Hong Kong, for example3. Particulates emitted from ships cause 60,000
cardiopulmonary and lung-cancer deaths each year worldwide4. Expanding harbours
to take vast ships destroys coastal ecosystems. And scrapping fleets of
obsolete smaller ships pollutes seas and soils, and damages workers' health,
especially in the developing world5.
The
industry is at a crossroads. The expected profits from larger ships are being
undermined by excess capacity, slowing trade and plunging transport prices. In
2015, container freight rates for the world's busiest shipping route — between
Asia and northern Europe — dropped by nearly 60% in three weeks. A dozen
shipping companies went bankrupt, including Denmark's Copenship and China's
Nantsing. Even the giant container-conveying Danish conglomerate Maersk
announced that it would lay off 4,000 employees by 2017 and delayed or
cancelled orders to build mega-ships.
Companies
face a dilemma. If they buck the trend of scaling up, they risk being less
competitive. Yet running mega-ships only part full wipes out the benefits of
economies of scale. Ships use more fuel per container when half-loaded than for
a full cargo.
The
future is green shipping: efficient marine transport with minimal health and
ecological damage6. Cleaner practices — especially on ship scrapping, emission
control and port management — are needed. Achieving this will require heroic
efforts by the industry and its engineers in collaboration with regulators,
port authorities and communities. Environmental impacts should be considered in
determining optimal routes and modes for delivery of goods.
Pollution problem
Shipping
is the most energy-efficient way to move large volumes of cargo. Yet ships emit
nitrogen oxides (NOx), sulfur oxides (SOx), carbon dioxide and particulate
matter (PM) into the atmosphere. Worldwide, from 2007 to 2012, shipping
accounted7 for 15% of annual NOx emissions from anthropogenic sources, 13% of
SOx and 3% of CO2. In Europe in 2013, ships contributed 18% of NOx emissions,
18% of SOx and 11% of particles less than 2.5 micrometres in size (PM2.5). For
road transport, the figures were 33%, 0% and 12%, respectively. Aviation, by
contrast, accounted for only 6%, 1% and 1%, respectively, and rail just 1%, 0%
and 0%.
Shipping
policies must be applied worldwide to be effective. Shipping and aviation
emissions are not addressed by global climate-change agreements, including the
deal made in Paris last December. The International Maritime Organization
(IMO), which regulates international shipping, is engaging — slowly. Releases
into the oceans of oils, noxious liquids, harmful substances, sewage and
garbage have been restricted since the 1980s by the International Convention
for the Prevention of Pollution from Ships (MARPOL), following a spate of
oil-tanker accidents. Air-pollution limits for shipping were adopted in 1997
but came into force only in 2005.
Energy
efficiency is the IMO's present focus. Starting in 2013, its Energy Efficiency
Design Index and Ship Energy Efficiency Management Plan aim to lower CO2
emissions from shipping through tighter technical requirements on engines and
equipment, maintenance regimes and voyage plans. No absolute
emissions-reduction targets were set. Unfortunately, long-term expansion in
global trade and growing ship numbers mean that even if these measures are
fully implemented, total shipping emissions are projected to quadruple from
1990 to 20508.
The
IMO has set up four 'emission-control areas' — the Baltic Sea, the North Sea,
the US Caribbean and the coastal waters of Canada and the United States — where
ships are required to minimize emissions mainly of SOx and NOx. These regions
exclude the world's ten largest container ports, such as the Chinese ports of
Shanghai, Shenzhen, Hong Kong and the South Korean port of Busan, which are all
in Asia (see 'The dirty ten'). We estimate that these ten sites alone
contribute 20% of port emissions worldwide.
A
few developed countries, including the United States, the United Kingdom and
Norway, limit the sulfur content of marine fuel in their national waters to
within 1,000 parts per million (p.p.m.). Most developing countries, including
India and China, permit dirtier fuels with 35,000 p.p.m. of sulfur. The
European Union fuel standard for cars is 10 p.p.m.
Ship
scrapping is heavily polluting. Asbestos, heavy metals and oils are toxic.
Workers are exposed to hazardous fumes. The EU has laws requiring that ships
registered in Europe be broken up only in licensed yards that meet strict
guidelines. But it is easy to change a ship's registration and demolish it in a
country with a more lax approach to labour and environmental protection.
India,
Bangladesh, and Pakistan are popular for ship scrapping9. In Bangladesh for
example, 40,000 mangroves — trees that stabilize many tropical coasts and are
habitats and breeding grounds for many species — were chopped down in 2009
alone to accommodate shipbreaking yards. The pollution from scrapping there has
caused an estimated 21 fish and crustacean species to become extinct. And
reportedly, each week one worker dies and seven are injured in the scrap yards
of Bangladesh.
Congestion
adds to pollution and disruption. Large volumes of cargo overwhelm ports,
surrounding roads and waterways. Hasty expansion or construction of berths and
canals to take more large ships can be environmentally disastrous. Where the
water in existing harbours is too shallow, port authorities may reclaim land
from the sea or build artificial islands in deeper waters.
Coastal
changes destroy ecosystems. Over the past three decades, about 75% of mangroves
have disappeared from Shenzhen, following port expansion and land reclamation.
Plans for the Porto Sul port in Brazil — slated to open in 2019 — identified 36
potential environmental impacts, including driving away dolphins and whales and
killing seabed fauna.
Traditional
shipping routes cannot keep up. The Panama Canal, which connects the Pacific
and Atlantic oceans, can currently handle vessels carrying only up to about
5,000 standard containers. A project to expand it to accept ships with 13,000
containers (the 'New Panamax' class) should be completed by May. But the
largest mega-ships, such as Maersk's E-class and Triple E-class (with
capacities between 14,000 and 18,000 containers), will still be unable to cross
(see 'Supersize ships'). In the meantime, heavy traffic at Panama, complicated
navigation and constant maintenance have led to a ten-day delay in voyage
times.
To
take advantage of the business opportunity, construction is scheduled to start
this year on a 280-kilometre-long canal through Nicaragua. This US$50-billion
project, funded by a billionaire-owned Hong Kong company, could destroy almost
400,000 hectares of tropical forests and wetlands, home to threatened and
endangered wildlife and indigenous communities10.
Public
concern about the pollution and health impacts of shipping remains muted
because the industry is a backbone of the global economy, and its activities
happen far from where most people live and often beyond the jurisdiction of
local regulators. We cannot rely only on new ship designs and engine innovation
to minimize the ecological footprint of shipping: today's ships might be in use
for another 20 years or more. Several issues must be addressed together to make
the industry greener.
Green shipping
Implementing
the following recommendations could save thousands of lives each year, ensure
cleaner coastal air and reduce ecological damage from shipping.
Clean
up ship scrapping. The IMO adopted the Hong Kong International Convention for
the Safe and Environmentally Sound Recycling of Ships in 2009, but only Norway,
Congo and France have acceded as of February 2016. The IMO's priority should be
to ensure that the principal scrappers — India, Bangladesh and Pakistan —
adhere to these guidelines. The first step is to set up local offices in these
countries to collect and analyse monitoring data independently and to propose
improvements to local governments. International loan or aid programmes to
these countries, sponsored by the World Bank or the Asian Development Bank, for
example, should demand clean ship-scrapping practices as an incentive. To
discourage transfer of scrapping elsewhere, a watch list of poorly performing
countries needs to be updated by IMO regularly until an international
convention enters into force.
Control
emissions. Stricter IMO emissions regulations are needed, including a cleaner
worldwide standard for sulfur released by combustion of marine fuel. A 97% cut
in SOx can be achieved by reducing the sulfur content from 35,000 p.p.m. to
1,000 p.p.m. fuel oil. Today's low oil price provides a great opportunity for
this transition to happen. The current cost of 1,000-p.p.m.-grade fuel oil
(around US$300 per tonne in Singapore, for example) is less than half of that
of the cheapest dirty fuel four years ago.
Marine
fuel is a sideline for oil refineries — only 2–4% of the total fuel market.
Stricter emissions standards will stimulate demand for high-quality fuel.
Incentive programmes (tax rebate and subsidies for producers) will be needed to
ensure a reasonable profit margin to recover the initial high investment in
developing countries, where there is little current capacity. Government
interventions will be needed in countries with state-run oil companies, such as
in China and India.
An
alternative is to install scrubbers for exhaust-gas cleaning on ships. Scrubber
units blend the exhaust gas with water or caustic soda to remove up to 99% of
SOx and 98% of particulate matter from high-sulfur fuel. At the moment, scrubbers
are expensive, costing $2 million for one ship. But China, for instance, could
equip its entire container fleet in one year by funding a 50% subsidy for
scrubbers. The total cost? Just 0.5% of the $150 billion per year it has spent
since 2013 to fight pollution. Shipping companies could recoup the other 50% in
one year from fuel savings. With a stricter emissions standard, the demand for
scrubbers would go up, and the costs down, as production scales.
Improve
port management. Port authorities should review the environmental impact of
their previous construction and disclose information on their future
development plans to demonstrate responsible management of public assets. They
should coordinate with transport-planning bureaus to seek the most economical
and environmentally friendly strategy to dispatch goods; the optimal capacities
of its terminals; and how to assist ships to load and unload quickly. Making
port-business statistics and the results of environmental-impact studies
accessible will allow the research community to be involved in the
decision-making process. Environmental non-governmental organizations should
campaign to increase public awareness of port development.
After
decades of loose oversight, it is time for shipping to get a whole lot greener.
Source: nature. 17 February 2016
