Dr. Mark Serreze received his M.S. degree from the University of Massachusetts, Amherst, and his PhD from the University of Colorado, Boulder, in 1989. He is at the Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO, and the National Snow and Ice Data Center, a unit of CIRES sponsored by NASA, NOAA, and NSF. His current research areas are Arctic hydro-climatology, synoptic variability (changes on a scale of days), and sea-ice variability. One of his finest achievments is having a brother who's an immunologist. |
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“We've put a hit on the system and we are in the midst of a grand global experiment. We will have to live with the outcome.”
The most defining feature of the Arctic Ocean is its floating sea-ice cover, which has traditionally ranged from a maximum extent of about 16 x 106 km2 in March to a minimum extent of 7 x 106 km2 at the end of the summer melt season in September. Consistent satellite-derived monthly time series of sea-ice extent are provided by the Nimbus-7 Scanning Multichannel Microwave Radiometer (October 1978 to August 1987) and the Defense Meteorological Satellite Program Special Sensor Microwave/Imager (1987 to present). Based on regression analysis of the combined record over the period 1979 to 2006, ice extent has declined for every month, most rapidly for September, for which the trend is –8.6 ± 2.9% per decade or about 100,000 km2 per year.
The sea ice was a record minimum in the satellite era since 1979 and probably in the last century. Compared to where it should have been, you've lost an area roughly twice the size of Texas.
Data for the past few years suggest an accelerating decline in winter sea-ice extent. “Something has fundamentally changed here, and the best answer is warming.”
I think what it’s [the decline in sea ice in 2006] really telling us is that this decline that we’ve seen in the Arctic sea ice covers starting back at least in 1979 since we’ve had good satellite records, and it appears much longer, is not at this point just a feature of inter-annual variability, a feature of natural variability; what we’re starting to see is a longer term change that can only be explained by the fact that the Arctic is strongly warming, at least in part due to the effects of greenhouse gases. So, it’s something that has us really concerned at this point.
To summarize, the observed sea-ice loss can in part be connected to arctic warming over the past several decades. Although this warming is part of a global signal suggesting a link with greenhouse gas (GHG) loading, attribution is complicated by a suite of contributing atmospheric and oceanic forcings. Given the agreement between models and observations, a transition to a seasonally ice-free Arctic Ocean as the system warms seems increasingly certain. The unresolved questions regard when this new arctic state will be realized, how rapid the transition will be, and what will be the impacts of this new state on the Arctic and the rest of the globe.
I see things going in a downward spiral. We might lose the Arctic sea ice cover in summer, maybe around the year 2060, maybe a little later, it depends on how things pan out. In the lifetime of some of our children, we’ll find the Arctic to be a radically different place. One with much less ice cover, and of course, this is going to have ramifications on the rest of the planet. So, I’m not too hopeful with where things stand right now; we’re seeing these radical changes in the Arctic now, it appears that they’re going to continue and get worse in the future. —Sources: Quotations from Mark Serreze's writings and interviews.
Recommended resources
The New York Times has produced a 5-episode video report on recent changes in the Arctic ice cap and their regional and global consequences. You can see it here; on the Channels list on the left, click "science" and then "The Big Melt."
Much interesting data, some of it technical, can be accessed from a NSIDC web site here.
Arctic polar sea ice cover maps can be viewed and compared here.
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