Archaeology News Online

In a new study, scientists found that aerosol particles released into the atmosphere from the burning of fossil fuels are a primary driver of changes in rainfall patterns across the globe. Top map: Spatial distribution of the annual-mean precipitation averaged from 1979-2008. Bottom: Time series of the  annual mean precipitation anomaly relative to the 1971-2000 climatology over the Sahel region of Africa  [Credit: Top: Global Precipitation Climatology Project (GPCP) data set. Bottom: Global Historical  Climatology Network (GHCN) data set. Background image: Drought - George Safonov] The results of the climate system-model simulations conducted by researchers Brian Soden and Eui-Seok Chung from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science revealed that changes in clouds, as a result of their interaction with these human-made aerosols in the atmosphere, are driving large-scale shifts in rainfall and temperature on Earth. A southward shift of the tropic

New research published in Nature Climate Change has revealed how strengthening winds on the opposite side of Antarctica, up to 6000kms away, drive the high rate of ice melt along the West Antarctic Peninsula. The path of the Kelvin waves that interact with the Antarctic Circumpolar Current and push warmer waters under  the ice shelves of the West Antarctic Peninsula. These waves are generated by strengthening winds,  6000km away, on the opposite side of the Antarctic [Credit: Ryan Holmes/NCI] Researchers from the ARC Centre of Excellence for Climate System Science found that the winds in East Antarctica can generate sea-level disturbances that propagate around the continent at almost 700 kilometers per hour via a type of ocean wave known as a Kelvin wave. When these waves encounter the steep underwater topography off the West Antarctic Peninsula they push warmer water towards the large ice shelves along the shoreline. The warm Antarctic Circumpolar Current passes quite close to the co

Climate change leads to loss of biodiversity worldwide. However, ecosystems with a higher biodiversity in the first place might be less affected a new study in Science Advances reports. An international research team found that when they experimentally warmed meadows, the diversity of nematode worms living in the soil went down in monocultures, whereas the opposite was true for meadows with many different herbaceous plant species. A predatory female nematode of the genus Clarkus under the microscope [Credit: Marcel Ciobanu] The last month was recorded as the warmest June ever in many parts of the world. Last year, 2016, was the warmest year in the modern temperature record. Our planet is constantly heating up. This poses direct threats to humans, like extreme weather events and global sea-level rise, but scientists are concerned that it may also affect our well-being indirectly via changes in biodiversity. The variety of life, from plants and animals to microorganisms, is the basis of

Land mammals and reptiles in the Pacific islands facing extinction due to habitat loss, hunting and other threats could be decimated by climate change, a study published Thursday said. Climate change poses a serious threat to Pacific island wildlife, such as on the Marshall Islands,  pictured in March 2016 when the islands flooded, from storms [Credit: AFP] Ocean-bound wildlife is particularly vulnerable to environmental pressures, especially endemic species living on only one or a handful of islands. Among other things, this remoteness makes migrating to another land mass nearly impossible. Dozens of species -- especially birds -- have also been wiped out over the last century by invasive species and disease brought by human settlers. For most Pacific island vertebrates -- animals with a backbone -- the current risk of extinction has been measured and catalogued in the Red List of threatened species, maintained by the International Union for the Conservation of Nature (IUCN). Scientis

Populations of endangered species reach a critical point in their life where they either survive or evolve towards extinction. Therefore, efforts to predict and even prevent the extinction of biological species require a thorough understanding of the underlying mechanisms. The Siberian tiger is an Endangered (EN) tiger subspecies. Three tiger subspecies are already extinct  [Credit: WikiCommons] In a new study published in EPJ B , Hatem Barghathi and colleagues from Missouri University of Science and Technology, USA, have investigated how environmental disturbance at random times could cause strong fluctuations in the number of individuals in biological populations. This, in turn, makes extinction easier, even for large populations. They found that environmental disorder can lead to a period of slow population increase interrupted by sudden population collapses. These findings also have implications for solving the opposite problem when attempting to predict, control and eradicate popu

A one trillion tonne iceberg -- one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice, monitored by the Swansea University-led MIDAS project, finally completed its path through the ice. Animation of the growth of the crack in the Larsen C ice shelf, from 2006 to 2017, as recorded  by NASA/USGS Landsat satellites [Credit: NASA/USGS Landsat] The calving occurred sometime between Monday 10th July and Wednesday 12th July, when a 5,800 square km section of Larsen C finally broke away. The final breakthrough was detected in data from NASA's Aqua MODIS satellite instrument, which images in the thermal infrared at a resolution of 1km. The iceberg, which is likely to be named A68, weighs more than a trillion tonnes. Its volume is twice that of Lake Erie, one of the Great Lakes. The iceberg weighs more than a trillion tonnes (1,000,000,000,000 metric tonnes), but it was already floating before it calved away so has no immedi

The Greenland ice sheet is often seen as a pristine environment, but new research has revealed that may not be the case. The Greenland ice sheet is often seen as a pristine environment, but new research has revealed that may not be the case  [Credit: IOP Publishing] A Danish-led study, published today in the journal Environmental Research Letters , examined how microbes from the ice sheet have the potential to resist and degrade globally-emitted contaminants such as mercury, lead, PAH and PCB. Dr Aviaja Hauptmann, from the University of Greenland, led the research. She said: "Globally emitted contaminants accumulate in the Arctic and are stored in the frozen environments of the cryosphere, essentially meaning they have become reservoirs of toxic chemicals. "Our understanding of how biological processes interact with contamination in the Arctic is limited, which is why we hope our study represents a large step forward in the understanding and solving of this problem." The

No bells tolled when the last Catarina pupfish on Earth died. Newspapers didn't carry the story when the Christmas Island pipistrelle vanished forever. Tropical forest logging has contributed to population declines in many animals,  including the Bornean gibbon, known for its whooping call  [Credit: Gerardo Ceballos] Two vertebrate species go extinct every year on average, but few people notice, perhaps because the rate seems relatively slow -- not a clear and present threat to the natural systems we depend on. This view overlooks trends of extreme decline in animal populations, which tell a more dire story with cascading consequences, according to a new study that provides the first global evaluation of these population trends. "This is the case of a biological annihilation occurring globally, even if the species these populations belong to are still present somewhere on Earth," said co-author Rodolfo Dirzo, a professor of biology. Mapping loss A 2015 study co-authored b

The orangutan population on the island of Borneo has shrunk by a quarter in the last decade, researchers said Friday, urging a rethink of strategies to protect the critically-endangered great ape. Borneo's orangutans are under threat from farming, climate change, and being hunted for food  [Credit: AFP/Bay Ismoyo] The first-ever analysis of long-term orangutan population trends revealed a worrying decline, they said. An international team of researchers used a combination of helicopter and ground surveys, interviews with local communities, and modelling techniques to draw a picture of change over the past ten years. Previous counts have largely relied on estimations based on ground and aerial surveys of orangutan nests. Some suggested that Bornean orangutan numbers were in fact increasing. The new findings, the team said in a statement, are "a wake-up call for the orangutan conservation community and the Indonesian and Malaysian governments who have committed to saving the spe

If there is anywhere for carbon dioxide to disappear in large quantities from the atmosphere, it is into the Earth’s oceans. There, huge populations of plankton can soak up carbon dioxide from surface waters and gobble it up as a part of photosynthesis, generating energy for their livelihood. When plankton die, they sink thousands of feet, taking with them the carbon that was once in the atmosphere, and stashing it in the deep ocean. MIT climate scientists have found that the ocean’s export efficiency, or the fraction of total plankton growth  that is sinking to its depths, is decreasing, due mainly to rising global temperatures [Credit: MIT News] The oceans, therefore, have served as a natural sponge in removing greenhouse gases from the atmosphere, helping to offset the effects of climate change. But now MIT climate scientists have found that the ocean’s export efficiency, or the fraction of total plankton growth that is sinking to its depths, is decreasing, due mainly to rising glob

A new analysis of Greenland's past temperatures will help scientists figure out how fast the island's vast ice sheet is melting, according to a new report from University of Arizona atmospheric scientists. Taken from the International Space Station in 2016, this picture of the southern tip of Greenland shows the island's vast  ice sheet fringed by glaciers that flow into the sea. The glaciers and ice sheet of Greenland cover a land area greater  than the European countries of Germany, France, Spain and Italy combined. If all Greenland's ice melted,  sea levels would rise by about 7 meters (23 feet) [Credit: NASA] The ice sheet has been shrinking since 1900 and the yearly loss of ice has doubled since 2003, other researchers have shown. The accelerated melting of the Greenland ice sheet is contributing to sea level rise. The glaciers and ice sheet of Greenland cover a land area greater than the European countries of Germany, France, Spain and Italy combined. If all Green

In a new study, scientists found that aerosol particles released into the atmosphere from the burning of fossil fuels are a primary driver of changes in rainfall patterns across the globe. Top map: Spatial distribution of the annual-mean precipitation averaged from 1979-2008. Bottom: Time series of the  annual mean precipitation anomaly relative to the 1971-2000 climatology over the Sahel region of Africa  [Credit: Top: Global Precipitation Climatology Project (GPCP) data set. Bottom: Global Historical  Climatology Network (GHCN) data set. Background image: Drought - George Safonov] The results of the climate system-model simulations conducted by researchers Brian Soden and Eui-Seok Chung from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science revealed that changes in clouds, as a result of their interaction with these human-made aerosols in the atmosphere, are driving large-scale shifts in rainfall and temperature on Earth. A southward shift of the tropic

New research published in Nature Climate Change has revealed how strengthening winds on the opposite side of Antarctica, up to 6000kms away, drive the high rate of ice melt along the West Antarctic Peninsula. The path of the Kelvin waves that interact with the Antarctic Circumpolar Current and push warmer waters under  the ice shelves of the West Antarctic Peninsula. These waves are generated by strengthening winds,  6000km away, on the opposite side of the Antarctic [Credit: Ryan Holmes/NCI] Researchers from the ARC Centre of Excellence for Climate System Science found that the winds in East Antarctica can generate sea-level disturbances that propagate around the continent at almost 700 kilometers per hour via a type of ocean wave known as a Kelvin wave. When these waves encounter the steep underwater topography off the West Antarctic Peninsula they push warmer water towards the large ice shelves along the shoreline. The warm Antarctic Circumpolar Current passes quite close to the co

Climate change leads to loss of biodiversity worldwide. However, ecosystems with a higher biodiversity in the first place might be less affected a new study in Science Advances reports. An international research team found that when they experimentally warmed meadows, the diversity of nematode worms living in the soil went down in monocultures, whereas the opposite was true for meadows with many different herbaceous plant species. A predatory female nematode of the genus Clarkus under the microscope [Credit: Marcel Ciobanu] The last month was recorded as the warmest June ever in many parts of the world. Last year, 2016, was the warmest year in the modern temperature record. Our planet is constantly heating up. This poses direct threats to humans, like extreme weather events and global sea-level rise, but scientists are concerned that it may also affect our well-being indirectly via changes in biodiversity. The variety of life, from plants and animals to microorganisms, is the basis of

Land mammals and reptiles in the Pacific islands facing extinction due to habitat loss, hunting and other threats could be decimated by climate change, a study published Thursday said. Climate change poses a serious threat to Pacific island wildlife, such as on the Marshall Islands,  pictured in March 2016 when the islands flooded, from storms [Credit: AFP] Ocean-bound wildlife is particularly vulnerable to environmental pressures, especially endemic species living on only one or a handful of islands. Among other things, this remoteness makes migrating to another land mass nearly impossible. Dozens of species -- especially birds -- have also been wiped out over the last century by invasive species and disease brought by human settlers. For most Pacific island vertebrates -- animals with a backbone -- the current risk of extinction has been measured and catalogued in the Red List of threatened species, maintained by the International Union for the Conservation of Nature (IUCN). Scientis

Populations of endangered species reach a critical point in their life where they either survive or evolve towards extinction. Therefore, efforts to predict and even prevent the extinction of biological species require a thorough understanding of the underlying mechanisms. The Siberian tiger is an Endangered (EN) tiger subspecies. Three tiger subspecies are already extinct  [Credit: WikiCommons] In a new study published in EPJ B , Hatem Barghathi and colleagues from Missouri University of Science and Technology, USA, have investigated how environmental disturbance at random times could cause strong fluctuations in the number of individuals in biological populations. This, in turn, makes extinction easier, even for large populations. They found that environmental disorder can lead to a period of slow population increase interrupted by sudden population collapses. These findings also have implications for solving the opposite problem when attempting to predict, control and eradicate popu

A one trillion tonne iceberg -- one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice, monitored by the Swansea University-led MIDAS project, finally completed its path through the ice. Animation of the growth of the crack in the Larsen C ice shelf, from 2006 to 2017, as recorded  by NASA/USGS Landsat satellites [Credit: NASA/USGS Landsat] The calving occurred sometime between Monday 10th July and Wednesday 12th July, when a 5,800 square km section of Larsen C finally broke away. The final breakthrough was detected in data from NASA's Aqua MODIS satellite instrument, which images in the thermal infrared at a resolution of 1km. The iceberg, which is likely to be named A68, weighs more than a trillion tonnes. Its volume is twice that of Lake Erie, one of the Great Lakes. The iceberg weighs more than a trillion tonnes (1,000,000,000,000 metric tonnes), but it was already floating before it calved away so has no immedi