What was done
The authors note that state-of-the-art climate models predict "the effect of any present and future global climatic change will be amplified in the polar regions as a result of feedbacks in which variations in the extent of glaciers, snow, sea ice and permafrost, as well as atmospheric greenhouse gases, play key roles."  However, they say that Polyakov et al. (2002a,b) have "presented updated observational trends and variations in Arctic climate and sea-ice cover during the twentieth century, which do not support the modeled polar amplification of surface air-temperature changes observed by surface stations at lower latitudes," and that "there is reason, therefore, to evaluate climate dynamics and their respective impacts on high-latitude glaciers."  Consequently, they did just that for the Archipelago of Svalbard, focusing on Spitsbergen (the Archipelago's main island) and the Longyearbreen glacier located in its relatively dry central region at 78°13'N latitude.

What was learned
In reviewing what was already known about the region, Humlum et al. report that "a marked warming around 1920 changed the mean annual air temperature (MAAT) at sea level within only 5 years from about -9.5°C to -4.0°C," which change, in their words, "represents the most pronounced increase in MAAT documented anywhere in the world during the instrumental period."  Then, they report that "from 1957 to 1968, MAAT dropped about 4°C, followed by a more gradual increase towards the end of the twentieth century."

With respect to the Longyearbreen glacier, their own work reveals it "has increased in length from about 3 km to its present size of about 5 km during the last c. 1100 years," and they say that "the meteorological setting of non-surging [our italics] Longyearbreen suggest this example of late-Holocene glacier growth represents a widespread phenomenon in Svalbard and in adjoining Arctic regions," which they describe as a "development towards cooler conditions in the Arctic" that "may explain why the Little Ice Age glacier advance in Svalbard usually represents the Holocene maximum glacier extension."

What it means
Climate change in Svalbard over the 20th century was a real rollercoaster ride, with temperatures rising more rapidly in the early 1920s than has been documented anywhere else before or since, only to be followed by a nearly equivalent temperature drop four decades later, both of which climatic transitions were totally out of line with what climate models suggest should have occurred.  In addition, the current location of the terminus of the Longyearbreen glacier suggests that, even now, Svalbard and "adjoining Arctic regions" are still experiencing some of the lowest temperatures of the entire Holocene or current interglacial, and at a time when atmospheric CO2 concentrations are higher than they have likely been for millions of years, both of which observations are also at odds with what climate alarmists claim about the strong warming power of atmospheric CO2 enrichment.  Hence, there is little reason to put much faith in their claims, or to get too excited if the Arctic were to warm a bit ... or even substantially and at a rapid rate.  It's done so before, and it will likely do so again.  In fact, it's only to be expected, seeing the region has a long way to go to recover from some of the coldest temperatures of the entire interglacial.

References
Polyakov, I., Akasofu, S.-I., Bhatt, U., Colony, R., Ikeda, M., Makshtas, A., Swingley, C., Walsh, D. and Walsh, J.  2002a.  Trends and variations in Arctic climate system.  EOS, Transactions, American Geophysical Union 83: 547-548.

Polyakov, I.V., Alekseev, G.V., Bekryaev, R.V., Bhatt, U., Colony, R.L., Johnson, M.A., Karklin, V.P., Makshtas, A.P., Walsh, D. and Yulin, A.V.  2002b.  Observationally based assessment of polar amplification of global warming.  Geophysical Research Letters 29, 1878, 25-1 - 25-4.