2008 tied with 2001 as the eighth warmest year on record, and climate change dominated polar news during the month of January.

A new comprehensive synthesis of past Arctic climates shows that temperature change is happening at a greater rate there than other places in the Northern Hemisphere. This warming is expected to continue, leading to glacier and ice-sheet melting, sea-ice retreat, coastal erosion, and sea level rise. An increasingly ice-free Arctic ocean raises the possibility of increased activity and necessitates new considerations in international cooperation among Arctic nations. Just before leaving office, outgoing President Bush released security directives about American military, economic, and diplomatic priorities in the region. A new Canadian documentary explores the activities of Russia, Canada, the United States, Denmark, and others to explore, map, and assert control over the area.

Climate change in the Arctic may also contribute to the advance of the treeline into areas previously characterized as tundra, the subject of a large-scale research effort in Canada.

Antarctica, too, is warming, despite a longstanding belief that a large part of the continent was cooling. A new study indicates that on average, the continent is warming at a rate comparable to the rest of the world even though East and West Antarctica are warming at different rates.

The melting of ice sheets in Antarctica and Greenland has the potential to raise sea level, but models and studies have suggested a wide range of possible increases. A new study using past climate records from annual growth rings of trees and ice cores suggests that the ocean could rise one meter within the next 100 years, three times higher than predictions from the IPCC report. Researchers explain that ice sheets have been observed to react to warming much more quickly than believed just a few years ago, and that studies from the ice age confirm that such rapid melting is possible.

Scientists are also finding new ways to collect data and improve climate models. Researchers have recently reported that bacterial levels in ice cores vary in response to climate conditions, a finding that might add a new and unique indicator to the physical and chemical benchmarks currently used. Over the next three years, a series of five flights of the HIAPER Pole-to-Pole Observations mission will allow for global, real-time sampling of greenhouse gases across a wide range of altitudes in the atmosphere and in some of the world’s most inaccessible regions. In Antarctica, NASA and the National Science Foundation have successfully launched a new super pressure balloon prototype that will enable new high-altitude scientific research. The final product will be a 22 million cubic foot balloon that can carry a one-ton instrument to an altitude of more than 110,000 feet. Using such a balloon costs much less than a satellite, and allows for retrieval and re-use of the scientific instruments.

 Climate change’s effect on polar bears has been well publicized, and now it seems that Antarctica’s iconic species may also be in jeopardy. Researchers from the Woods Hole Oceanographic Institution used mathematical models to predict the effect of climate change on emperor penguin populations. The models predict that sea ice continues to decline at the rates published in the latest IPCC report, the median population size of a large emperor penguin colony will likely shrink from 3,000 to 400 breeding pairs by the end of the century. This type of decline would put the population at serious risk of extinction.

Finally, researchers analyzing temperature data have noted that the seasons have shifted nearly two days earlier. The scientists explain that the difference between summer and winter land temperatures has decreased over a 50-year period, and that peak summer and low winter temperatures occur earlier in the calendar year. More research is needed to explain this shift, though researchers say that human-generated greenhouse gases may be a cause.

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