On 25 February 2010 20:07, Tony Wright <ton...@tpg.com.au> wrote: > Meanwhile: > > I had a look at David Connors sent link: > http://earthobservatory.nasa.gov/Features/WorldOfChange/sea_ice_south.php > and it should be pointed out that this refers to sea ice and whether that > has an impact on increasing sea levels. > > I looked another link on this site: > http://earthobservatory.nasa.gov/Features/WorldOfChange/sea_ice.php > which refers to sea ice in the northern hemisphere, which has been melting > at a faster rate than down south. > > This is all consistent with what the Australian Antarctic Division have > said. > > Again from the NASA site supplied: > "Since 1978, satellites have monitored sea ice growth and retreat, and they > have detected an overall decline in Arctic sea ice. The rate of decline > steepened after the turn of the twenty-first century. In September 2002, > the > summer minimum ice extent was the lowest it had been since 1979. Although > the September 2002 low was only slightly below previous lows (from the > 1990s), it was the beginning of a series of record or near-record lows in > the Arctic. This series of record lows, combined with poor wintertime > recoveries starting in the winter of 2004-2005, marked a sharpening in the > rate of decline in Arctic sea ice. Sea ice did not return to anything > approaching the long-term average (1979-2000) after 2002." > > > But sea ice actually doesn't have anywhere near as much of an impact as > land-based ice does on sea level. It is analogous to ice cubes floating in > a > glass. When sea ice melts, it doesn't increase the volume (much). However, > if land ice melts, and the water flows into the sea, the sea level does > rise. > > However, what it does do is decrease our overall albedo. Whether ice is land or sea, its reflectance is the same.
> -- Meski "Going to Starbucks for coffee is like going to prison for sex. Sure, you'll get it, but it's going to be rough" - Adam Hills
