The flaring of natural gas is contributing more than 40 percent of the sooty black carbon in the Arctic, a level that raises new concerns about the link between energy production and ice melt, according to a new study.
The findings in Atmospheric Chemistry and Physics underscore the importance of environmental regulations in the remote region as oil and gas production continues, according to analysts. They also reveal the unique conditions of the Arctic, considering that the contribution of gas flaring to black carbon concentrations is smaller in other areas of the globe, according to the study's co-author, Zbigniew Klimont, a research scholar at the Austria-based International Institute for Applied Systems Analysis.
"Development of further oil and gas production capacity in areas close to the Arctic needs stronger environmental legislation assuring that uncontrolled venting and flaring of gas is minimized," said Klimont.
Previously, there was little understanding of the role of gas flaring in black carbon in the Arctic, partially because there was an assumption that its role was smaller than other factors like combustion from cookstoves, he said. Inventories of black carbon in the past, for instance, did not consider flaring to be of "high relevance."
"It has been long thought that the major sources of black carbon, and pollution in general, to the Arctic were industrial (non-flaring) emissions in Northern Europe and Asia," said Patricia Quinn, a scientist at the National Oceanic and Atmospheric Administration who did not participate in the research. She said the paper was a "well-done" study that could be significant for targeting emission reductions.
Flaring emissions are close by and rising
The flaring emissions are relatively close to the Arctic, so they are more likely to be deposited on snow and ice than higher-altitude aerosol plumes coming from farther away, she said. Emission inventories for flaring by the oil industry are relatively new, she noted.
Sooty black carbon is generated from the incomplete combustion of fuels like wood and dung, and drives ice melt by darkening the surface and lowering its ability to reflect sunlight. Natural gas is a byproduct of oil production, and is often burned off in remote locations where there is little piping infrastructure.
The research team tapped satellite data showing the volumes and locations of flared gas globally. They compared those numbers to national estimates of volumes of flared gas.
The gas volume numbers were then plugged into a model that estimated black carbon emissions and distribution. An additional model calculated concentrations of the sooty substance in the Arctic, taking weather patterns and seasonal variations into consideration.
Natural gas flaring in high latitudes caused roughly 42 percent of annual mean black carbon concentrations between 2008 and 2010, the researchers said. In March, the number rose to 52 percent.
Globally, flaring contributes about 3 percent of black carbon emissions, according to the study.
There is a good possibility that improved measurements will show an even higher contribution to black carbon levels from flaring in the Arctic, considering that flaring emissions are still poorly understood, said Klimont.
Russia is the major emitter
Much of the black carbon is coming from oil and gas operations in Russia, said Andreas Stohl, a researcher at the Norwegian Institute for Air Research and study co-author. For that reason, black carbon concentrations in the Russian north can be about 10 times higher than in other Arctic regions, he said.
The remaining 58 percent of black carbon in the Arctic is coming from a combination of transportation emissions, fires, biomass, and residential combustion via stoves and boilers, said Klimont.
He said the incorporation of flaring -- along with improved measurements of residential combustion -- brought the team's modeling much closer to ground measurements of black carbon at six monitoring stations in Alaska, Canada, Finland, Norway and Greenland. The team assessed how residential emissions changed throughout the year, rather than using an average.
"None of the [earlier] models could successfully simulate the black carbon seasonal cycle observed at measurement stations, and all models strongly underestimated concentrations in winter and early spring," he said.
Black carbon levels measured at ground stations in Canada, Alaska and Greenland have been going down, but it is still not clear what the broader trends are elsewhere in the Arctic, according to Quinn. Measurements at higher latitudes -- which typically are gathered via aircraft campaigns -- are "sporadic," she said.
Time for an Arcticwide rule?
Flaring of gas dropped globally by about 18 percent between 2005 and 2011, according to the Global Gas Flaring Reduction Partnership, part of the World Bank. However, production in places such as the Bakken oil play helped reverse that trend in 2011. The long-term trend could also shift with oil production in Brazil, Iraq and the United States, the partnership said in a recent newsletter.
Ellen Baum, a senior scientist at the Clean Air Task Force, said the study could "move the dial" and spur discussions about an Arcticwide standard on flaring. There may need to be a re-evaluation of the common assumption that flaring is the "climate friendly alternative" to venting of natural gas, because flaring destroys methane.
"There are climate risks we need to be more aware of," she said. Reinjection of gas is one of several options to curb flaring, she said.
Many Arctic nations such as Norway have good regulations, but there is still a long way to go across the region generally with new flaring limits and enforcement of existing rules, she said. The Arctic's remoteness makes operations difficult for many oil and gas companies, but that may change with the ongoing decline in ice, she said.
"At some point, there will be a jump in production," she said.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500
