We have reported on the role of black carbon (soot) as a major non-greenhouse gas human climate forcing in the Arctic; e.g. see

New Study On The Role Of Soot Within the Climate In The Higher Latitudes And On “Global Warming

where an article in Scientific American by David Biello based on a study by Charlie Zender, a climate physicist at the University of California, Irvine stated

““…. on snow—even at concentrations below five parts per billion—such dark carbon triggers melting, and may be responsible for as much as 94 percent of Arctic warming”.

Now we have yet another human climate forcing that was reported by Rex Dalton of Nature News in the article

How aircraft emissions contribute to warming – Aviation contributes up to one-fifth of warming in some areas of the Arctic.

The article includes the text

“The first analysis of emissions from commercial airline flights shows that they are responsible for 4–8% of surface global warming since surface air temperature records began in 1850 — equivalent to a temperature increase of 0.03–0.06 °C overall.

The analysis, by atmospheric scientists at Stanford University in Palo Alto, California, also shows that in the Arctic, aircraft vapour trails produced 15–20% of warming.”

The photo in the news release has the caption

“Aircraft emissions could be having a dramatic effect on the warming of the Arctic”.

Clearly, as we summarized in our EOS article

Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell, W. Rossow, J. Schaake, J. Smith, S. Sorooshian, and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union

the human role in the climate system is much more than the human emissions of CO2 and a few other greenhouse gases.