Amazing Science

According to data just now available, the total surface area of the summertime Arctic Sea that is covered in ice has reached the lowest point ever recorded.

Every (northern) summer the sea ice in the Arctic melts to some degree, reaching a minimum around the middle of September. Over the last several years, the amount of ice at this minimal point has been lower than previously recorded. Accurate records go back only a few decades, so this shift in ice cover reflects only the most recent period of Anthropocentric Global Warming (AGW).

Harvard scientists have discovered that intense summer storms can force water vapor into the dry and cold stratosphere through a process called convective injection. The presence of such water vapor, which normally stops at the tropopause (the boundary between the troposphere and the stratosphere), changes the threshold temperature at which ozone is destroyed by chemistry dependent on manmade chlorofluorocarbons (CFCs), which are still present in the atmosphere despite an international ban on their use. The chemical reactions that destroy ozone typically occur only at very cold temperatures. The presence of water vapor raises the temperature at which ozone loss takes place, to the point that threshold conditions for ozone destruction are routinely crossed during the summer above the United States and possibly elsewhere. The frequency and intensity of these summer storms is expected to increase with climate forcing due to increasing levels of heat-trapping atmospheric carbon dioxide and methane. Reductions in stratospheric ozone would allow more DNA-damaging ultraviolet radiation to reach Earth, with potential biological effects on human beings, animals, and plants.

How did the Earth get its oceans? The primordial Earth was a seething ball of magma, so the water that it began with would have evaporated into space. As a result, planetary scientists have long debated which of two types of objects, comets or asteroids, were more responsible for delivering Earth’s water.

A new study says that asteroids were the source. The authors analyzed the isotopic abundances of nitrogen and hydrogen in 86 primitive meteorites, and found that they coordinate with Earth’s. Asteroids had already been the favored source. Studies of solar system dynamics suggest that there was a period of time around 3.9 billion years ago, called the Late Heavy Bombardment, during which the Earth would have been barraged, mostly by asteroids.

Japanese could become extinct in 1,000 years if current population trends continue, according to researchers. Researchers at Tohoku University Graduate School of Economics in Sendai unveiled a population clock — available on the university's website — that showed the nation ending up with no children aged under 15 by May 18, 3011.

The calculation is based on the fact that the current population of children aged up to 14 — 16.6 million — is shrinking at the rate of one every 100 seconds, Agence France-Presse reported. The researchers reportedly did not take into account potential disasters, wars, or other global changes. "If the rate of decline continues, we will be able to celebrate the Children's Day public holiday on May 5, 3011 as there will be one child," AFP cited Hiroshi Yoshida, an economics professor at Tohoku University, as saying. "But 100 seconds later there will be no children left. The overall trend is towards extinction, which started in 1975 when Japan's fertility rate fell below two."

The eastern edge of the Namib Desert of southwestern Africa (the pro-Namib) is home to a mysterious phenomenon called “fairy circles”–nearly circular barren patches within a sparse matrix of small short-lived grass species.

In Namibia of southwestern Africa, the sparse grasslands that develop on deep sandy soils under rainfall between 50 and 100 mm per annum are punctuated by thousands of quasi-circular bare spots, usually surrounded by a ring of taller grass. The causes of these so-called “fairy circles” are unknown, although a number of hypotheses have been proposed.

A pair of NASA satellite images taken just four days apart tells a potentially worrying story of melting ice in the polar summer.

The first, snapped from orbit on July 8, shows about 40 percent of the Greenland ice sheet shaded in pink or red to illustrate probable or confirmed surface melting. The second photo, taken on July 12, shows nearly the entire land mass — 97 percent — blotched in a red hue.

In a typical year, only about half of the Greenland ice sheet undergoes this kind of melting before it later refreezes. But the rapidity and extent of the July change is what has caught scientists off guard, said Thomas Mote, a professor at the University of Georgia, who helped confirm the data from three satellites.

Scientists note that besides covering a large area, the melting is happening at the top of the ice cap, where temperatures are coldest. They blame a massive heat dome parked over the island that has set up perfect conditions for melting high-altitude snow and ice.

Alarming? "I wouldn't use that word," say Mote. "We know from looking at ice cores that melt at the highest levels of elevation in Greenland has occurred in the past — not in our lifetimes, and not since the era of satellites, but it certainly has occurred." The last time it happened was about 150 years ago, in 1889, according to ice core records. But the Greenland melt roughly coincides with a giant chunk of ice described as "twice the size of Manhattan," breaking off the Petermann Glacier in northern Greenland.