Russian sea captain Dimitri Zinchenko has been steering ships through the pack ice of Antarctica for three decades and is waiting to see evidence of the global warming about which he has heard so much.

Zinchenko's vessel, the Spirit of Enderby, was commissioned in January last year to retrace the steps of the great Antarctic explorer Ernest Shackleton, marking the century of his Nimrod expedition of 1907-09.

Spirit of Enderby was blocked by a wall of pack ice at the entrance to the Ross Sea, about 400km short of Shackleton's base hut at Cape Royds. Zinchenko says it was the first time in 15 years that vessels were unable to penetrate the Ross Sea in January. The experience was consistent with his impression that pack ice is expanding, not contracting, as would be expected in a rapidly warming world. "I see just more and more ice, not less ice."

Two of the Arctic ice sites show April 16 ice at recent record levels. The Japanese site IJIS has a seven year April record going back to 2003, and reports 2009 levels at the highest extent on record for the date: 13,649,219 km2.

The Danish Meteorological Institute has a five year database, and also shows April 16 ice extent as the highest in their short record.

Ice is expanding in much of Antarctica, contrary to the widespread public belief that global warming is melting the continental ice cap.

The results of ice-core drilling and sea ice monitoring indicate there is no large-scale melting of ice over most of Antarctica, although experts are concerned at ice losses on the continent's western coast.

Antarctica has 90 per cent of the Earth's ice and 80 per cent of its fresh water. Extensive melting of Antarctic ice sheets would be required to raise sea levels substantially, and ice is melting in parts of west Antarctica. The destabilisation of the Wilkins ice shelf generated international headlines this month.

However, the picture is very different in east Antarctica, which includes the territory claimed by Australia.

East Antarctica is four times the size of west Antarctica and parts of it are cooling. The Scientific Committee on Antarctic Research report prepared for last week's meeting of Antarctic Treaty nations in Washington noted the South Pole had shown "significant cooling in recent decades".

Australian Antarctic Division glaciology program head Ian Allison said sea ice losses in west Antarctica over the past 30 years had been more than offset by increases in the Ross Sea region, just one sector of east Antarctica.

Denver - Hundreds of stranded travelers resumed their journeys Saturday after spending the night at shelters when a powerful spring storm walloped the Rocky Mountains and foothills west of Denver with more than 3 feet of snow.

Officials reopened an 80-mile stretch of Interstate 70 between Golden and Vail that had been closed Friday, said Colorado Department of Transportation spokesman Bob Wilson. Drivers were cautioned to expect heavy traffic and sloppy road conditions.

"It's not the I-70 you know in a June afternoon," Wilson said.

Storm warnings were dropped as the bulk of the storm moved east into Kansas.

About 15,000 homes and businesses were without power in Denver and areas north and west of the city. The heavy snow had weighed down power lines and tripped system circuit breakers. Piles of snow and closed roads were preventing crews from reaching some areas, Xcel Energy spokesman Joe Fuentes said, adding that crews hoped to restore power by 11 a.m. Sunday.

The study, being published Thursday in the journal Nature, suggests that a sudden rise of 6.5 feet to 10 feet occurred within a span of 50 to 100 years about 121,000 years ago, at the end of the last warm interval between ice ages.

"The potential for sustained rapid ice loss and catastrophic sea-level rise in the near future is confirmed by our discovery of sea-level instability" in that period, the authors write.

Yet other experts on corals and climate are faulting the work, saying that big questions about coastal risks in a warming world remain unresolved.

Among the most momentous and enduring questions related to human-caused global warming are how fast and how high seas may rise. Studies of past climate shifts, particularly warm-ups at the ends of ice ages, show that fast-melting ice sheets have sometimes raised sea levels worldwide in bursts of up to several yards in a century.

A question facing scientists is whether such a rise can occur when the world has less polar ice and is already warm, as it is now, and getting warmer.

Citing the evidence from fossil coral reefs, the authors of the new study say with conviction that the answer is yes.

The study focuses on a set of fossil reef remains exposed in excavations for channels at a resort and water park, Xcaret, about 35 miles south of Cancún on the east coast of the Yucatán Peninsula.

On these taxing days, when we become a defiantly bipartisan nation of whiners convinced that we are handing over to the Internal Revenue Service our blood and sweat and mother's milk, our pound of flesh and firstborn young, maybe it's time for a little perspective.

Legions before us have donated all these items and more to the public till, and not just metaphorically speaking, either. Benjamin Franklin was right to equate paying taxes with a deeply organic behavior like dying. It turns out that giving up a portion of one's income for the sake of the tribe is such a ubiquitous feature of the human race that some researchers see it as crucial to our species' success. Without ritualized taxation, there would be precious little hominid representation.

Moreover, plenty of nonhuman animals practice the tither's art, too, demanding that individuals remit a portion of their food, labor, comfort or personal fecundity for the privilege of group membership. And just as the I.R.S. depends on threat of audit as much as it does on anybody's sense of civic responsibility, so do other toll-collecting species ensure compliance by meting out swift punishment against tax cheats. For example, Marc Hauser of Harvard University has found that when a rhesus monkey is out foraging and comes upon a source of especially high-quality food, like, say, a batch of ripe coconuts, the monkey is expected to give a characteristic food call to alert its comrades to the find. "The bad thing about doing a food call is that it means others will come and take some of the food," said Laurie R. Santos, who studies the primates at Yale University. Yet a monkey who opts to keep mum about its discovery could face worse. Should other group members happen by while the private feast is under way, they will not only claim the food for themselves, but the most dominant among them will also beat the cheater indignantly.

The "albino" flowers lack the pigment that gives bluebells their traditional purplish blue colour.

They were found growing among a mass of blue flowers at Bluebell Wood in Ferry Meadows Country Park, Peterborough.

Ashley Wheal, ranger at the park, said: "We only have two white plants, so they are very special.

"It is very, very strange, probably only happening in one in every 10,000 bulbs.

Since April Fool's Day expired, there has been nothing but bad news about Earth's various ice shelves circulating through the news. Antarctica's Wordie and Larsen ice shelves? The first is simply gone, and the second is disappearing fast. How about the Connecticut-sized Wilkins shelf? It has fragmented into polar pieces after the ice tether holding it to the Antarctic peninsula snapped this week, signaling that the Earth is undergoing some profound changes.

So what do melting ice shelves a world away have to do with the rest of us? That is where the fools come in.

This intriguing image is being scrutinized by Italian scientists trying to unravel exactly how the Earth moved during Italy's devastating quake last week.

The picture shows shock waves radiating from the epicentre of the massive 6.3 seismic event in the medieval town of L'Aquila.

Its rainbow-coloured interference patterns were deduced using 'synthetic aperture radar' (SAR) data from the European Space Agency's (ESA) Envisat and the Italian Space Agency's COSMO-SkyMed satellites.

Some people think of bees as something to be feared. But without bees, humans would not be able to survive. It's not just that they provide us with honey and wax; they are also one of the world's most important pollinators. (In fact, bees native to Canada do not produce honey; honeybees are imports - and not all bees sting!)

Close to 90 per cent of the world's plants rely on pollinators for fertilization and reproduction - including many of the plants we use for food. Beyond providing food, plants anchor soil to prevent erosion and fuel the nutrient cycle by decomposing and absorbing nutrients. Bees aren't the only pollinators; butterflies, hummingbirds, and bats, among other animals, provide pollination. But bees are the most common pollinators. If we lose the bees, we lose the plants, and if we lose the plants, well...