Science Daily

Humans migrated out of Africa as the climate shifted from wet to dry about 60,000 years ago, according to new paleoclimate research. What the northeast Africa climate was like when people migrated from Africa into Eurasia between 70,000 and 55,000 years ago is still uncertain. The new research shows around 70,000 years ago, the Horn of Africa climate shifted from a wet phase called 'Green Sahara' to even drier than the region is now.

The significant scale of human impact on our planet has changed the course of Earth history, an international team of scientists.

Currently, winter has still a firm grip on Antarctica. At this time of the year, the Weddell Sea usually is covered with a thick layer of sea ice. In spite of the icy temperatures in the region, satellite images depict a large ice-free area in the middle of the ice cover.

Ancient DNA extracted from fossil bones and museum specimens has shed new light on the mysterious loss of the Tasmanian tiger (thylacine) from Australia's mainland.

Investigations to predict changes in sea levels and their impacts on coastal systems are a step closer, as a result of a new international collaboration.

A new iceberg calved from Pine Island Glacier -- one of the main outlets where ice from the interior of the West Antarctic Ice Sheet flows into the ocean.

A team of researchers has collected new data that shows a significant decrease in snow precipitation close to the ground in Antarctica, which has an impact on the ice sheet surface mass balance.

For the first time, researchers have been able to use mud deposited on the depths of the ocean floor to measure changes in the speed of deep-sea currents. Using mud as a current meter could help scientists to identify fluctuating patterns in ocean current speeds stretching back into prehistory, enabling climate change researchers to get a better sense of how currents behave over time.

The onset of the last ice age may have forced some bird species to abandon their northerly migrations for thousands of years, says new research led by an ornithologist. The study challenges a long-held presumption that birds merely shortened their migratory flights when glaciers advanced south to cover much of North America and northern Europe about 21,000 years ago.

DNA in lake sediment forms a natural archive displaying when various fish species colonized lakes after the glacial period. Scientists' analyses of the prevalence of whitefish DNA in sediment reveal that the whitefish came to Lake Stora Lögdasjön in Västerbotten already 10,000 years ago, whereas Lake Hotagen in Jämtland had its whitefish only 2,200 years ago.

Gravity waves form in the atmosphere as a result of destabilizing processes. The effects of gravity waves can only be taken into consideration by including additional special components in the models.

Researchers are exploring the changing chemistry of the Arctic's atmosphere to help answer the question of what happens as snow and ice begin to melt.

Arctic sea ice appeared to have reached its yearly lowest extent on Sept. 13, scientists have reported. Analysis of satellite data showed that at 1.79 million square miles (4.64 million square kilometers), this year's Arctic sea ice minimum extent is the eighth lowest in the consistent long-term satellite record, which began in 1978.

Studies of craters in the Baltics (Estonia) are giving insights into the many impacts that have peppered the Earth over its long history. In southeastern Estonia, scientists have dated charcoal from trees destroyed in an impact to prove a common origin for two small craters, named Illumetsa. A third submarine crater located on the seabed in the Gulf of Finland has been measured and dated with with precision.

This September, the extent of Arctic sea ice shrank to roughly 4.7 million square kilometres, scientists have determined.

Evidence of wildfires dating back 20,000 years was recently discovered in the Massif du Queyras, in the heart of the French Alps, 2,240 meters above sea level. This discovery echoes the recent wildfires in the Arctic tundra, where the presence of trees have become increasingly common.

Researchers have made a discovery that could create roads that melt off ice and snow during winter storms. Their secret? Adding a little paraffin wax to the road's concrete mix.

Bristlecone pine and limber pine trees in the Great Basin region of the western United States are like two very gnarled, old men in a slow-motion race up the mountaintop, and climate change is the starting gun, according to a new study. The study shows that the tree line has been steadily moving upslope over the past 50 years in the Great Basin.

A kauri tree trapped in a New Zealand swamp for 30,000 years may have overturned the idea that a slowdown in ocean currents in the North Atlantic may be entirely responsible for Dansgaard-Oeschger events and the characteristic bi-polar see-saw, which sees the Antarctica cool while the Arctic warms during glacial periods. The research reveals a mechanism that generates a 20,000 km long atmospheric bridge, reaching from Antarctica to the Arctic.

By studying climate changes that took place thousands of years ago, we can better understand the global climate system and predict Earth's future climate. A multi-organization research team has discovered evidence of rapid climate changes on a millennial-to-centennial scale that occurred 780 to 760 thousand years ago.