The study is the first to provide a global estimate of maritime shipping's total contribution to air particle pollution based on direct emission measurements. The authors estimate ships emit about 1,100 tons of particle pollution globally each year.
Ship pollutants affect both global climate and the health of people living along coastlines, according to the study authors. The findings appear online the week of Feb. 23 in the Journal of Geophysical Research.
"Since more than 70 percent of shipping traffic takes place within 250 miles of the coastline, this is a significant health concern for coastal communities," said lead study author Daniel Lack, a researcher with the NOAA-supported CU Cooperative Institute for Research in Environmental Sciences based at NOAA's Earth System Research Laboratory in Boulder.
Earlier research by one of the study's co-authors, James Corbett of the University of Delaware, linked particle pollution to premature deaths among coastal populations.
Commercial ships emit both particle pollution and carbon dioxide, but they have opposite effects on the climate, said the researchers. The particles have a global cooling effect that is at least five times greater than the global warming effect from the ships' CO2 emissions.
The particles affect both climate and health, said the researchers. CO2 from ships makes up roughly 3 percent of all human-emitted CO2 and almost 30 percent of smog-forming nitrogen oxide gases.
During summer 2006, Lack and colleagues aboard the NOAA ship Ronald H. Brown analyzed the exhaust from over 200 commercial vessels, including cargo ships, tankers and cruise ships in the Gulf of Mexico, Galveston Bay and the Houston Ship Channel. The researchers also examined the chemistry of particles in ship exhaust to understand what makes ships such hefty polluters.
Ships emit sulfates, the same particles associated with diesel-engine cars and trucks and which have resulted in tighter regulations regarding on-road vehicle fuel standards, according to the research team. Sulfate emissions from ships vary with the concentration of sulfur in ship fuel, the authors found.
Globally, fuel sulfur content is capped under the International Convention for the Prevention of Pollution from Ships. As a result of the cap, some ships use "cleaner," low-sulfur fuels, while others continue to use the high-sulfur counterparts.
But sulfates make up just under half of shipping's total particle emissions, according to the NOAA-CU study. Organic pollutants and sooty, black carbon -- which make up the other half of emissions -- are not directly targeted by today's regulations. A 2008 study by Lack's team focused exclusively on soot.
Emissions of non-sulfate particles depend on the operating speed of the engine and the amount of lubricating oil needed to deal with wear and tear from burning less-refined fuels, according to the researchers. "Fortunately, engines burning 'cleaner,' low-sulfur fuels tend to require less complex lubricants," said Corbett. "So the sulfur fuel regulations have the indirect effect of reducing the organic particles emitted."
One surprising result of burning low-sulfur fuels was that while total particle emissions diminish, the time the remaining particles spend in the air appears to increase. It's while they're airborne that particles pose a risk to human health and affect climate, according to the study.
Lack and colleagues found that the organic and black carbon portion of ship exhaust is less likely to form cloud droplets. As a result, the particles remain suspended for longer periods of time before being washed to the ground through precipitation.
Daniel Lack | EurekAlert!
Further reports about: > Air Pollution > CO2 > CO2 emissions > Coastlines > Environmental Sciences > Global Climate > SHIP > Ship pollutants > black carbon > cargo ships > coastal communities > emission measurements > maritime shipping > maritime shipping's > particle pollution > premature death > premature deaths among coastal populations
Climate change weakens Walker circulation
20.10.2017 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen
Shallow soils promote savannas in South America
20.10.2017 | Senckenberg Forschungsinstitut und Naturmuseen
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research