Science Daily

Shark populations in the Mediterranean are highly divided, an international team of scientists has shown. The study used genetic techniques to investigate the population structure of the small-spotted shark, Scyliorhinus canicula. The species is common throughout Europe and has been eaten since ancient times, as documented in Roman mosaics.

Instead of carbon dioxide being like a blanket that slowly warms the planet, after about a decade most warming comes from melting ice and snow and a more moist atmosphere, which both cause Earth to absorb more shortwave radiation from the sun.

Researchers use robotic ocean gliders to study how warm water is making its way to Antarctic ice sheets -- and how this warming ultimately leads to rising ocean levels.

Biogeochemical signals in 2.5-billion-year-old carbonate rocks from Brazil reveal that sulfur-consuming bacteria were active at a time when ocean sulfur levels were low. Geologists focused on sulfur isotopes in ancient carbonate rocks. The study sheds light on Earth's early atmospheric chemistry.

Human-set fires by a small Polynesian population in New Zealand about 750 years ago may have caused fire-vulnerable forests to shift to shrub land over decades, rather than over centuries, as previously thought.

Researchers have drawn parallels between decline of Assyrian civilization and today's situation in Syria and Iraq. There's more to the decline of the once mighty ancient Assyrian Empire than just civil wars and political unrest. Archaeological, historical, and paleoclimatic evidence suggests that climatic factors and population growth might also have come into play.

Scientists have provided the first systematic examination of the social information polar bears may glean from scent left in the paw prints of other polar bears. The authors also suggest that scent communication in polar bears may be compromised if climate-change driven sea ice losses in the Arctic intensify.

A geologist has demonstrated that earthquakes -- not climate change, as previously thought -- affect the rate of landslides in Peru. "Geologic records of landslide activity offer rare glimpses into landscapes evolving under the influence of tectonics and climate," says a researcher whose expertise includes geomorphology and tectonics. "Because deposits from individual landslides are unlikely to be preserved, it's difficult to reconstruct landslide activity in the geologic past. Therefore, we've developed a method that measures landslide activity before and after the last glacial-interglacial climate transition in Peru."

A mechanism that could turn out to be a big contributor to warming in the Arctic region and melting sea ice has been identified by scientists. They found that open oceans are much less efficient than sea ice when it comes to emitting in the far-infrared region of the spectrum, a previously unknown phenomenon that is likely contributing to the warming of the polar climate.

Heinrich events, in which large masses of icebergs rapidly broke free from ice sheets during the last ice age, are thought to have influenced global climate by interrupting ocean circulation patterns with a large influx of freshwater. However, new research suggests the variations in the height of the ice sheet that happen in these events might also influence global climate.