Americas News
50 Mile North American ECA "Would Be Just as Effective"
Independent environmental and energy consultant Dr. Ranajit (Ron) Sahu says the decision to make the North American Emissions Control Area (ECA) extend 200 nautical miles from the coast was "not based on very solid science," and when the 0.10 percent sulfur cap for marine fuel comes into effect in 2015, a 50 mile ECA zone would be equally effective.
Speaking to delegates who had gathered for the GreenTech 2013 conference in Vancouver, Canada last week, Sahu called on regulators to reconsider the legislation, saying they had failed to take into account the impact on short-sea shipping in their decision making process.
"When it came to the 200 mile requirement of the North American ECA," said Sahu, "what was the technical basis for that? Why 200?"
"It is not based on very solid science. And I say that categorically."
Global vs Local
Sahu explained that it was important to distinguish between local and global emissions, and to not "lump all pollutants into the same bucket."
For local pollutants, such as the sulfur dioxide (SOx) targeted by the current ECA rules, the key thing to understand is the distance between where they are emitted and where their impact will be felt, he explained.
For global pollutants such as carbon dioxide (CO2), that distance is not important, as the goal is to reduce the global average.
"You don't want to be doing good on local emissions and then inadvertently drive up [global emissions]," he said. "You want to have both objectives being met."
Unlike other shipping sectors, almost all short-sea shipping voyages are within the ECA, which means their cost of compliance is higher.
Sahu argued that cost could cause a modal shift to land based transport, inadvertently raising global greenhouse gas emission levels.
50 = 200?
Sahu said he made a dispersion model to establish if a smaller ECA zone could have the equivalent benefits on land as the current 200 nautical mile ECA.
In his model, Sahu found that the further out to sea that pollutants were emitted, the lower their recorded concentration level was on the shore.
However the relationship between concentration and distance was not linear, and that the drop off was "dramatic."
"You don't have to go too far, you certainly don't have to go 200 miles, before the shore based concentrations are negligible," he said.
Based on his data, Sahu determined that a 50 nautical mile ECA would be as equally effective as a 200 mile ECA.
"If you use ECA fuel which is 0.1 percent sulfur...you have a sulfur dioxide concentration which is about 1 percent of your national average ambient air quality standard."
"If you take 1 percent sulfur at 80km [50 miles] on that same shore based receptor, you have 0.55 percent concentration of the national ambient air quality standard."
"You have equal to or better then ECA performance where it matters, which is at the receptor sitting on the shore."
"Why wouldn't you then allow people to use 1 percent at 80 km?" he asked, "because the outcomes are the same or better for where it matters at the shore, or anywhere beyond."
Sahu concluded that he supports the 2015 0.10 percent North American ECA sulfur cap at a distance of 50 miles, and a 1.00 percent sulfur cap out to 200 nautical miles.
"And there's precedent for that - the Caribbean has a boundary of 50 miles," he noted.
Regulatory Decisions
Responding to the presentation, a Senior Program Engineer from Environment Canada, Richard Holt, said the modelling undertaken by the Canadian Government did in fact show impacts "well inland" from pollutants emitted "right up to the 200 mile limit."
Discussing the dispersion model used by Sahu, Holt said it only accounted for the movements of a single ship, and that "we typically wouldn't use that kind of model for any regulatory decision."
Holt also noted the dispersion model only looked at SOx, and did not take into account other factors such as particulate matter formation.
