Annals of science about the effect of global warming on the Arctic has been described in part one of a three-part series. The Alaskan village of Shishmaref sits on an island known as Sarichef, 5 miles off the coast of the Seward Peninsula. In the early 1990s, seal hunters began to notice that the sea ice was changing it was forming later in the fall and breaking up earlier in the spring. this caused the island to become more vulnerable to storm surges. In 2002 the entire village voted to move to the mainland. The National Academy of Sciences undertook its first rigorous study of global warming in 1979 mentions studies by Syukuro Manabe and James Hansen. The Ad Hoc Study Group on Carbon Dioxide and Climate, headed by Jule Charney, found that if carbon dioxide emissions continued to increase, the climate changes would be severe. It’s now 25 years since that report was issued, and, in this period, carbon-dioxide emissions have increased from 5 billion a year to 7 billion and the earth’s temperature has steadily risen. The world is now warmer than it has been at any point in the last 2 millennia. The impacts of global warming are no longer just hypothetical. Nearly every major glacier in the world is shrinking. The oceans are becoming not just warmer but more acidic; the difference between day and night time temperatures is diminishing; and plants are blooming weeks earlier than they used to. These are the warning signs that the Charney panel cautioned against waiting for. The most dramatic changes are occurring in the Arctic, which is melting. Most of the land in the Arctic is underlaid by zones of permafrost. The writer visited Fairbanks and Deadhorse, Alaska, with University of Alaska geophysicist ad permafrost expert Vladimir Romanovsky describes signs that the permafrost which has existed for 120,000 years-is melting. Writer observed Romanovsky collecting data from some of his 60 electronic monitoring stations. Rising temperature can cause the organic material that has been frozen for millennia to break down, giving off carbon dioxide or methane. In 1997, the Des Groseilliers expedition found that the Arctic sea-ice depth had declined significantly. Donald Perovich, of the Cold Regions Research and Engineering Laboratory (CRREL), studies the interaction of solar radiation with sea ice. Anything that changes the earth’s albedo changes how much energy the planet absorbs, with dire consequences. The ice-albedo feedback is thought to be a major reason why the Arctic is warming so rapidly mentions the Madison Boulder. Antarctic ice cores show that carbon-dioxide levels today are significantly higher than they’ve been in the last 420,000 years. Some of the climate models Perovich has assembled predict that the perennial sea-ice cover in the Arctic will disappear entirely by 2080. In 1859, British physicist John Tyndall identified the natural greenhouse effect. Greenhouse gases absorb infrared radiation and then remit it; if these gas levels increase, the earth’s temperature will also rise, mentions Svante Arrhenius. Swiss Camp is a research station set on Greenland’s ice sheet, which is the second largest on earth mentions Konrad Steffen, Swiss Camp’s director. Much of what’s known about the earth’s climate over the last 100,000 years comes from ice cores drilled in central Greenland. Ten years ago, Jay Zwally, a NASA scientist, installed G.P.S. receivers around Swiss Camp to study changes in the ice sheet’s elevation. While discussing the rise in sea levels due to global warming thermohaline circulation mentions that no nation has a keener interest in climate change than Iceland. Oddur Sigurdsson heads the Icelandic Glaciological Society, which surveys the country’s 300 glaciers, which have been rapidly declining. The glacier S6Iheimajokull has shrunk by 1100 feet in the last decade discusses last fall’s Reykjavik symposium on global warming. The study found that temperatures in the Artic were rising at a surprising rate and that humans had become the “dominant factor” influencing the climate mentions oceanographer Robert Corell.