The effects of rerouting aircraft around the arctic circle on arctic and global climate

[FloridaJohn]

The paper can be found here

Abstract:

Climate data suggest greater warming over the Arctic than lower latitudes, and the most abundant direct source of black carbon and other climate-relevant pollutants over the Arctic is cross-polar flights by international aviation. A relevant question is whether rerouting cross-polar flights to circumnavigate the Arctic Circle reduces or enhances such warming. To study this issue, a model accounting for subgrid exhaust plumes from each individual commercial flight worldwide was used with 2006 global aircraft emission inventories that treated cross-polar flights and flights rerouted around the Arctic Circle (66.56083 °N), respectively. Rerouting increased fuel use by 0.056 % in the global average, mostly right outside the Arctic Circle, but most of the associated black carbon and other emissions were removed faster because they were now over latitudes of greater precipitation and lesser stability. Rerouting also reduced fuel use and emissions within the Arctic Circle by 83 % and delayed pollutant transport to the Arctic. The Arctic reduction in pollutants, particularly of black carbon, decreased Arctic and global temperature and increased Arctic sea ice over 22 years. Although the slight increase in total CO₂ emissions due to rerouting may dampen the benefit of rerouting over more decades, rerouting or even partial rerouting (allowing cross-polar flights during polar night only) may delay the elimination of Arctic sea ice, which will otherwise likely occur within the next 2–3 decades due to global warming in general. Rerouting may increase worldwide fuel plus operational costs by only ~$99 million/yr, 47–55 times less than an estimated 2025 U.S.-alone cost savings due to the global warming reduction from rerouting.

[Vergent]

The paper can be found here

Abstract:

Climate data suggest greater warming over the Arctic than lower latitudes, and the most abundant direct source of black carbon and other climate-relevant pollutants over the Arctic is cross-polar flights by international aviation. A relevant question is whether rerouting cross-polar flights to circumnavigate the Arctic Circle reduces or enhances such warming. To study this issue, a model accounting for subgrid exhaust plumes from each individual commercial flight worldwide was used with 2006 global aircraft emission inventories that treated cross-polar flights and flights rerouted around the Arctic Circle (66.56083 °N), respectively. Rerouting increased fuel use by 0.056 % in the global average, mostly right outside the Arctic Circle, but most of the associated black carbon and other emissions were removed faster because they were now over latitudes of greater precipitation and lesser stability. Rerouting also reduced fuel use and emissions within the Arctic Circle by 83 % and delayed pollutant transport to the Arctic. The Arctic reduction in pollutants, particularly of black carbon, decreased Arctic and global temperature and increased Arctic sea ice over 22 years. Although the slight increase in total CO₂ emissions due to rerouting may dampen the benefit of rerouting over more decades, rerouting or even partial rerouting (allowing cross-polar flights during polar night only) may delay the elimination of Arctic sea ice, which will otherwise likely occur within the next 2–3 decades due to global warming in general. Rerouting may increase worldwide fuel plus operational costs by only ~$99 million/yr, 47–55 times less than an estimated 2025 U.S.-alone cost savings due to the global warming reduction from rerouting.

Interesting, though I doubt that rerouting aircraft would help. With the foreseen increase in trans arctic shipping, where the fuel and carbon savings are enormous globally, but a great increase for the arctic. Rerouting aircraft might offset some of the arctic increases from shipping, but I do not think it could reverse it.

[mempho]

Interesting, though I doubt that rerouting aircraft would help. With the foreseen increase in trans arctic shipping, where the fuel and carbon savings are enormous globally, but a great increase for the arctic. Rerouting aircraft might offset some of the arctic increases from shipping, but I do not think it could reverse it.

Globalization is the cause of climate change.

Sent from my Milestone X 2

[TerryM]

Wasn't there something like a 2C rise in temperature over the US when air traffic was halted after 9/11. Could it be that the jet trails have been protecting the Arctic from even higher summer temperatures? Perhaps routing them away from the Arctic in winter allowing more radiation to escape, then back in the summer to ease insolation would help.

Terry

[FloridaJohn]

Wasn't there something like a 2C rise in temperature over the US when air traffic was halted after 9/11.

About 1.8°C according to this paper here (pdf, 1 page).

What the orginal paper (of this thread) seems to be saying, is that the exhaust from the planes overflying the arctic is settling on the ice, darkening it, which makes it melt faster. By re-routing the planes, the ice stays whiter, and melts slower.

But then it also says that the increasing temperatures will erase that effect in short order, so re-routing the jets is only a short-term solution. Plus, you have the effect of more fuel being used to fly a further distance, which helps to increase warming faster, which reducing the time this solution would work.

I chalk it up as something that is interesting, but the rewards are not great enough to make any changes.

On the other hand, the paper I linked to in this post, seems to imply that even more flights over the arctic will keep the temperatures lower, slowing the melting of the ice. Like I said, interesting.