July 2000 -- Here's a reminder for people worried that large blocks of ice breaking off Antarctica signal global warming: Ice melts in summer.

In March 2000, news reports buzzed with word that not one, but two, enormous icebergs the size of small states had broken off ice shelves around the southern continent.

News reports were quick to blame human-induced global warming. A Reuters story, for example, said "Researchers say large chunks are breaking off of Antarctica for several reasons, some due to global warming ... [they] stress human-induced global warming can speed the process."

The article continued that if Antarctica's ice sheets continue to shrink, "the process could not only help raise ocean levels but could help shift ocean circulation and weather patterns, bringing drought, severe storms and the wider spread of tropical diseases."

To make things worse, in May 2000 another three massive icebergs -- ranging in size from 107 to 41 miles long, and 20 miles wide, broke loose from Antarctica. But icebergs breaking off Antarctica is old news.

In October 1998 the U.S. National Ice Center in Maryland reported an iceberg larger than the state of Delaware had broken off the Ronne Ice Shelf in Antarctica. To this press release an Associated Press writer warned "[s]ome scientists believe the breaking off, or calving, of icebergs may be an indicator of global warming."

In spring 1995, an iceberg nearly as large as Rhode Island broke off an Antarctic ice shelf. However, this calving followed two abnormally cold winters there, reported the World Climate Review.

And before that, a "Delaware-sized" iceberg calved from an Antarctic ice sheet in October 1987, the National Ice Center reported. The largest reported iceberg was in 1956 and was more than twice the size of Connecticut, the center said.

Why is this happening?

The fact is that when it's winter in the northern hemisphere, it's summer in the southern. In fact, during Antarctica's summer more solar radiation reaches the surface at the South Pole than is received at the Equator in an equivalent period. As a result, shelf ice melts and icebergs break free in late summer in the southern hemisphere, during what is the late winter in the northern hemisphere.

When the bitter Antarctic winter settles in during the summer months in the northern hemisphere, the opposite happens. Then, in what the Chicago Tribune called "the world's biggest annual climatic event", frigid winds sweep across the ocean from Antarctica's interior, freezing some 20 to 30 square miles of sea water every minute.

The floating ice sheet grows from one million to 7.2 million square miles by September, then melting and drifting away during the summer that follows "down under". "The annual expansion and contraction of the Antarctic ice sheet -- 6 million square miles -- is almost twice the area of the U.S.," the Tribune reported.

"The biggest misconception that needs to be put to rest is that [the March 2000 iceberg calving] is some kind of effect of global warming, or that the ice shelf is unstable and Antarctica is breaking up," said Matthew Lazzara, a meteorologist at the Antarctic Meteorology Research Center at the University of Wisconsin in Madison, as reported by National Geographic News.

"This is a normal calving that is due or overdue," Lazzara said. "The Ross Ice Shelf needs to break off every 50 to 100 years to maintain itself. This is part of the natural hydrologic cycle, and it's providing us with a wonderful opportunity to take a closer look and actually watch it as it happens."

Nonetheless, media speculation continues on the effect of presumed man-made global warming on arctic regions. For example, in June 2000 a major newspaper reported that presumed global warming may finally open up the Holy Grail of the early North American explorers, the "Northwest Passage" from Europe to Asia.

"Global warming may soon provide what the early sailors sought in vain: a shortcut ocean route from Europe to the fabled riches of the East," wrote Ruth Walker in the Christian Science Monitor June 7. "With the polar ice cap in the Canadian Arctic melting ... [I]n the next couple of decades, commercial ships may start plying the Arctic route instead of going through the Panama Canal, a shortcut of more than 4,000 nautical miles."

For a different perspective on climate change, call The Greening Earth Society at (800) 529-4503, or visit their web site.