Smeltingen av Vest-Antarktis skyter fart. Området er på størrelse med Texas og smelter raskere fordi den ligger under vann. Hvis den skulle smelte vil havet stige med 25 centimeter.
Climatic changes appear to be destabilizing vast ice sheets of western Antarctica that had previously seemed relatively protected from global warming, researchers reported yesterday, raising the prospect of faster sea-level rise than current estimates.
90 prosent av verdens is finnes i Antarktis. Temperaturer og nedbør har ikke forandret seg . Det er havtemperaturen og strømmene som har endret seg og påvirker Vest-Antarktis fordi isen ligger under vann.
The Antarctic ice sheet is shrinking despite land temperatures for the continent remaining essentially unchanged, except for the fast-warming peninsula.
The cause, Rignot said, may be changes in the flow of the warmer water of the Antarctic Circumpolar Current that circles much of the continent. Because of changed wind patterns and less-well-understood dynamics of the submerged current, its water is coming closer to land in some sectors and melting the edges of glaciers deep underwater.
«Something must be changing the ocean to trigger such changes,» said Rignot, a senior scientist with NASA’s Jet Propulsion Laboratory. «We believe it is related to global climate forcing.»
«Both Greenland and the West Antarctic ice sheet are huge bodies of ice and snow, which are sitting on land,» said Rajendra Pachauri, chief of the IPCC, the United Nations’ scientific advisory group. «If, through a process of melting, they collapse and are submerged in the sea, then we really are talking about sea-level rises of several meters.» (A meter is about a yard.) Last year, the IPCC tentatively estimated that sea levels would rise by eight inches to two feet by the end of the century, assuming no melting in West Antarctica.
Escalating Ice Loss Found in Antarctica
Sheets Melting in an Area Once Thought to Be Unaffected by Global Warming
Washington Post-art er fra 14. januar, men BBC World Service hadde en melding i natt om økt smelting, faktisk en tidobliing i forhold til tidligere.