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
Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute
Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences
07.12.2016 | Health and Medicine