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Something peculiar is happening in the azure waters off the rocky cliffs of Ischia, Italy. There, streams of gas-filled volcanic bubbles rising up to the surface are radically changing life around them by making seawater acidic. Stanford researchers studying species living near these gassy vents have learned what it takes to survive in acidic waters, providing a glimpse of what future oceans might look like as they grow more acidic.

Volcanic carbon dioxide seeps from the ocean floor near Ischia, Italy [Credit: Pasquale Vassallo, Stazione Zoologica Anton Dohrn]

Their findings, published in Nature Communications, suggest that ocean acidification driven by human-caused carbon dioxide emissions could have a larger impact than previously thought.

"When an organism's environment becomes more acidic, it can dramatically impact not only that species, but the overall ecosystem's resilience, function and stability," said Stanford marine biologist Fiorenza Micheli, lead author on the paper. "These transformations ultimately impact people, especially our food chains."

A natural laboratory

Most ocean acidification studies to date have taken place in laboratories, making it impossible to assess how whole ecosystems comprised of multiple, interacting species would be affected. The real-life laboratory provided researchers an opportunity to examine dozens of species, from sea urchins to marine snails, that live in areas of different acidity along Ischia's volcanic carbon dioxide vents. In addition to studying how species diversity changed with acidification, they analyzed species traits, such as diet and growth, that influence how well the ecosystem performs. For example, sea snails were smaller in more acidic water, as their shells take longer to grow and are thinner and more brittle. These harmful effects on sea snails, a key food for animals higher up in the food chain, may affect fish populations.

Overall, the researchers found that the active venting zones with the most acidic waters were home to not only the least number of species, but also the lowest amounts of "functional diversity" – the range of ecosystem-support services or roles that each species can provide.

"Studying the natural carbon dioxide vents in Ischia allowed us to unravel which traits from different species, like snail shell strength, were more vulnerable to ocean acidification. These results illuminate how oceans will function under different acidification scenarios in the future," said lead author Nuria Teixidó, a marine biologist from Stazione Zoologica Anton Dohrn in Italy, who was a visiting researcher at Stanford during the research.

Acidification in the waters of Ischia displaced long-lived species, such as corals, that form habitat for other species – a process already often witnessed on reefs across the world. The researchers also found that high levels of carbon dioxide and more acidity favored species with short life spans and fast turnover as they are the only species that can resist these environmental conditions. This change could lead to further diversity loss and instability in the oceans, as biodiversity tends to increase an ecosystem's stability.

Biodiversity loss is mapped along a natural CO2 gradient [Credit: Nuria Teixidó, Stazione Zoologica Anton Dohrn]

A broader application

Localized case studies such as Ischia can shed light on how future global environmental conditions may affect ocean life. Beyond losing biodiversity, ocean acidification will threaten food security for millions of people who depend on seafood, along with tourism and other ocean-related economies.

"The effects of ocean acidification on whole ecosystems and their functioning are still poorly understood," said Micheli, a professor of biology. "In Ischia, we have gained new insights into what future oceans will look like and what key services, like food production and coastal production, will be lost when there is more carbon dioxide in the water."

Author: Nicole Kravec | Source: Stanford University [December 11, 2018]

NOAA's annual report card on the Arctic, released today at the American Geophysical Union fall meeting in Washington, D.C., measures the changing climate of the polar region including warmer air and ocean temperatures and declines in sea-ice that are driving shifts in animal habitats.

Eyeing the Arctic: The southern Greenland town of Narsaq. Photo taken during a NASA Operation IceBridge flight April 26, 2018 [Credit: NASA/Joe MacGregor]

Now in its 13th year, the 2018 Arctic Report Card is a peer-reviewed report that provides an annual status update on the region and compares these observations to the long-term record. It was compiled from the research of 81 scientists working for governments and academia in 12 nations. This information can be used to inform decisions by local, state and federal leaders as Arctic residents confront the challenges and opportunities posed by a rapidly changing climate and ecosystem.

"The environmental changes in the Arctic underscore why NOAA continues to invest in Arctic research and activities, which improve the nation's economic competitiveness, national security, and the sustainable management of natural resources," said retired Navy Rear Adm. Timothy Gallaudet, Ph.D., acting under secretary of commerce for oceans and atmosphere at NOAA, who led the news conference to release the report card. "This report will also help guide NOAA's priorities in better understanding the role of the Arctic in climate change and extreme weather; sustaining and growing fisheries; and supporting adaptation and economic opportunities in the region."


This year's report shows that the Arctic region experienced the second-warmest air temperatures ever recorded; the second-lowest overall sea-ice coverage; lowest recorded winter ice in the Bering Sea; and earlier plankton blooms due to early melting of sea ice in the Bering Sea.

In addition to annual updates on ocean temperature, snow cover, tundra greenness and melting on the Greenland Ice Sheet, the report card also includes reports on multi-year environmental changes, including a long-term population decline of the region's iconic wildlife species, the caribou. Other multi-year essays focused on the expansion northward of toxic harmful algae and significant concentrations of microplastic pollution that are transported by ocean currents into the Arctic Ocean from other parts of the global ocean.

Declining Arctic sea ice: The 2018 Arctic Report Card found the Arctic region had the second-lowest overall sea-ice coverage on record. The map shows the age of sea ice in the Arctic ice pack in March 1985 (left) and March 2018 (right) . Ice that is less than a year old is darkest blue. Ice that has survived at least 4 full years is white [Credit: Maps were provided by NOAA Climate.gov and based on data provided by Mark Tschudi./University of Colorado/ CCAR (NOAA Climate.gov)]

This report card is just one of many aspects of NOAA's role in the Arctic region. NOAA, alongside many partners, is monitoring Arctic conditions, pioneering innovative technologies, and creatively collecting data and other scientific information.

For example, new technology is revolutionizing our understanding of the Arctic's changing environment, beginning to fill critical gaps in ocean and atmospheric observations. This technology is unmanned, fast, cost-effective, sturdy enough to withstand icy temperatures, and able to collect quality data for lengthy periods. Further, NOAA Polar-orbiting satellites fly over the Arctic 28 times daily, collecting data vital to improve weather forecasts, help fisheries increase catch, and support safe, efficient navigation in challenging waters. Additionally, as Arctic waters become increasingly ice-free, and commerce and other interests grow, NOAA is working to update nautical charts and calculate tide and current predictions.

Source: National Oceanic and Atmospheric Administration (NOAA) [December 11, 2018]

Seventy percent of the current infrastructure in the Arctic has a high potential to be affected by thawing permafrost in the next 30 years. Even meeting the climate change targets of the Paris Agreement will not substantially reduce those projected impacts, according to a new study published in Nature Communications.

UAF researcher Vladimir Romanovsky poses near Fairbanks, Alaska in a place where permafrost has thawed, causing a surface disruption [Credit: University of Alaska Fairbanks]

"Much more needs to be done to prepare Alaska and Alaskans for the adverse consequences of coming changes in permafrost and climate," said Vladimir Romanovsky, a scientist with the University of Alaska Fairbanks Geophysical Institute who has been monitoring permafrost across Alaska for 25 years.

Permafrost is ground that is frozen year-round for a minimum of two years. When it thaws, it can change from solid earth into mud. In many cases, the ground will slump, leading to destructive failure in any structures erected there.

"These observations have led me to believe that the global warming is not a 'fake' but the reality," Romanovsky said. "And here, in Alaska, we are dealing already and will be dealing even more in the near future with this reality."

Romanovsky is one of the study's authors, along with researchers from Finland, Norway, Russia and Michigan. The research is the first to explicitly show the amount of fundamental infrastructure across the Northern Hemisphere that is at risk of structural failure from permafrost thaw caused by climate change.

The paper reports that by 2050, about three-quarters of the population now living on permafrost, about 3.6 million people, will be affected by damage to infrastructure from permafrost thaw. In Alaska, about 340 miles of the trans-Alaska oil pipeline traverses ground where near-surface permafrost may thaw by 2050.

"The results show that most fundamental Arctic infrastructure will be at risk, even if the Paris Agreement target is achieved," the authors write. However, after 2050, attaining the Paris Agreement goals would make a clear difference in potential damage to infrastructure.

The authors looked at measurements of ground temperature, annual thaw depth and other data to make their projections. They note that because of the uncertainties, the amount of infrastructure at risk from permafrost thaw is probably not much smaller than their estimate, but could be substantially larger.

Damage to industrial facilities such as pipelines could lead to major ecosystem disruption if it results in spills. Energy supplies, national security and general economic activity could be adversely affected as well, the authors write. The Yamal-Nenets region in northwestern Siberia is the source of more than one-third of the European Union's pipeline imports of natural gas, for example.

Many parts of the Arctic's infrastructure have relatively short lifespans. Planners and engineers need to know in detail where permafrost is most likely to thaw as they plan for replacements, upgrades and maintenance. This study mapped such areas at a resolution of 0.6 miles, allowing them to target mitigation where it is most needed.

Source: University of Alaska Fairbanks [December 11, 2018]

Small, local patches of habitat could be playing a much bigger role in conserving biodiversity than you think, according to new research.

Eastern rosella at Edithvale wetland [Credit Wayne Butterworth]

The global study just published in the Proceedings of the National Academy of Sciences looked at the conservation values of vegetation patches in 27 countries on four continents, and considered their size and distance to other habitat.

The results were surprising according to lead researcher Professor Brendan Wintle from Melbourne University.

"Compared to large and well connected habitat areas, small and isolated patches of habitat have generally been treated as not very important to conservation," said Professor Wintle. "What we have found, however, is that small and isolated habitat areas are very important to the survival of many rare and endangered species."

"The environment is suffering a death by a thousand cuts," Wintle continued. "We need to re-think vegetation management regulations and policies that allow small patches of vegetation to be destroyed."

Co-author Dr. Sam Veloz, Climate Adaptation Group Director at Point Blue Conservation Science, added "We have many existing processes in place to fund restoration or conservation activities that are largely focused on large patches of habitat. While it's important to continue these efforts, our paper emphasizes that small but important habitat patches should be included in an overall conservation portfolio."

An example from the paper explored suitable habitat for four songbird species in California and Oregon (the streaked horned lark, savannah sparrow, Western meadowlark and the Oregon vesper sparrow). Research showed that highly fragmented parts of the study areas for each species contain habitat patches of very high conservation value. And the four species studied have ranges primarily in those small, isolated patches.

Dr. Heini Kujala from the University of Melbourne, another co-author, said that once you start considering how much habitat is left for a species, small patches can be very valuable.

"Small habitat patches can sometimes be the last pieces of a once widespread habitat. For species that rely on this type of habitat that makes them very important," said Dr. Kujala.

"Definitely we are not saying that it is an improvement to cut up big habitat areas into smaller pieces, rather that many of the small pieces that we have left are really important for conservation."

The study's authors hope that the research will raise awareness among planners, land managers, scientists, and the community about the value of small vegetation patches.

Source: University of Melbourne [December 11, 2018]

The future of the world's coral reefs is uncertain, as the impact of global heating continues to escalate. However, according to a study published in Nature Climate Change, the response of the Great Barrier Reef to extreme temperatures in 2017 was markedly different to one year earlier, following two back-to-back bouts of coral bleaching. Remarkably, corals that bleached and survived 2016 were more resistant in 2017 to a recurrence of hot conditions.

Researchers found that the response of corals to heat stress during the second of two unprecedented back-to-back bleaching events on the Great Barrier Reef was markedly different from the first [Credit: Tane Sinclair-Taylor]

"Dead corals don't bleach for a second time. The north lost millions of heat-sensitive corals in 2016, and most of the survivors were the tougher species. As a result of bleaching, the mix of species is changing very rapidly," said lead author Prof Terry Hughes, Director of the Australian Research Council Centre of Excellence for Coral Reef Studies (Coral CoE), headquartered at James Cook University.

"We were astonished to find less bleaching in 2017, because the temperatures were even more extreme than the year before," he said.

The new research highlights the extent of damage, or "geographic footprint" of multiple coral bleaching events across the 2,300 km length of the world-heritage listed area.

The back-to-back heatwaves bring the total number of mass bleaching events on the Great Barrier Reef to four over the past two decades (in 1998, 2002, 2016 and 2017). The scientists found that only 7% of the Great Barrier Reef escaped bleaching entirely since 1998, and after the 2017 event, 61% of reefs have now been severely bleached at least once.

During an underwater survey, a researcher records the bleaching severity of a massive Porites coral colony on the Great Barrier Reef [Credit: Justin Marshall]

"We found, using the National Oceanic and Atmospheric Administration's (NOAA) satellite-based coral bleaching tools, that corals in the north of the Great Barrier Reef were exposed to the most heat stress in 2016. A year later, the central region saw the most prolonged heating," said co-author Dr Mark Eakin, from NOAA's Coral Reef Watch program, in Maryland, USA.

The southern third of the Great Barrier Reef was cooler in both years due to local weather conditions, and escaped with only minor bleaching.

"It's only a matter of time before we see another mass-bleaching event, triggered by the next marine heatwave, driven by global heating," said co-author Dr Andrew Hoey of Coral CoE at James Cook University. "One of the worst possible scenarios is we'll see these southern corals succumb to bleaching in the near future."

"The outcome in 2017 depended on the conditions experienced by the corals one year earlier. We called that 'ecological memory,' and show that these repeating events are now acting together in ways that we didn't expect," said Prof Hughes.

"We've never seen back-to-back mass coral bleaching before on the Great Barrier Reef, in two consecutive summers. The combined footprint has killed close to half of the corals on two-thirds of the world's largest reef system," said Dr Hoey.

"We need urgent global action on greenhouse emissions to save the world's coral reefs. Australia should be -- but regrettably isn't -- at the forefront of tackling global heating," said Prof Hughes.

Source: ARC Centre of Excellence in Coral Reef Studies [December 10, 2018]

The new study, which detected bacteria from humans in the genus Salmonella and Campylobacter in Antarctic and Subantarctic marine birds, reveals the fragility of polar ecosystems and warns about the risk of massive deaths and extinctions of local fauna populations due pathogens.

These zoonotic agents, which cause common infections in humans, are caught by scavenger marine birds in contact with humans or livestock, and spread around the southern ocean [Credit: Jacob González-Solís/University of Barcelona-IRBio]

Reverse zoonosis: when the human species infects other living beings

Explorers, whalers, scientists -and lately, tourists-, are examples of human collectives that moved to the furthest regions of the planet. Some studies have claimed for years that there had been cases of reverse zoonosis, that is, infections humans give to other living beings. Despite some previous signs, scientific studies on zoonotic agents in the Antarctic and Subantarctic areas have been fragmented. Therefore, evidence is spread and not completely convincing in this field.

The new study, published in the journal Science of the Total Environment, studies the potential transmission of bacteria from humans to marine bird populations in four areas of the Antarctic and Subantarctic ecosystems. "Chronology and potential pathways for reverse zoonosis in these ecosystems are complex and difficult to study, but it seems they can be clearly related to the proximity of the fauna to inhabited areas and the presence of research stations", says Professor Jacob González-Solís, from the Department of Evolutionary Biology, Ecology and Environmental Sciences of the UB and IRBio.

Antibiotic-resistant bacteria in polar ecosystems

The study confirms the first evidence of reverse zoonosis related to the presence of human-origin bacteria Salmonella and Campylobacter in polar fauna. One of the warning signs was, in particular, the identification of Campylobacter strains, which are resistant to ciprofloxacin and enrofloxacin (common antibiotics in medicine and veterinary).

"Finding common Campylobacter genotypes in human species or livestock was the definite hint to prove that humans can be introducing pathogens in these regions", says Marta Cerdà-Cuéllar, researcher at the IRTA-CReSA. "These Salmonella and Campylobacter strains, which are a common cause for infections in humans and livestock, do not usually cause death outbreaks in wild animals. However, the emerging or invasive pathogens that arrive to highly sensitive populations -such as the Antarctic and Subantarctic fauna- could have severe consequences and cause the local collapse and extinction of some populations".

Northen and Southern Hemisphere: migrating route for marine birds and pathogens

The study shows the risk of reverse zoonosis is higher in areas that are closer to inhabited areas, such as the Flakland Islands, and probably the Tristan da Cunha archipelago. In this situation, the biological connectivity between Antarctic and Subantarctic communities through marine birds is a factor that would speed up the circulation of zoonotic agents among the ecosystems from different latitudes.

"This could be the case, for instance, of the Subantarctic parasite Stercorarius antarcticus: a scavenger marine bird could get the pathogen and spread it from Subantarctic latitudes to the Antarctica", says González-Solís.

Polar areas: not all the biodiversity is protected

The Antarctic Treaty protocol on Environmental Protection sets a series of principles that can be applied to human activity in Antarctica to reduce the human footprint in the white continent. However, some Subantarctic areas -which are also the habitat of birds such as the brown skua or the giant petrel- are not protected by the protecting regulation and could become the entrance for pathogen agents in polar ecosystems.

"Our results show it is easier for humans to introduce pathogen agents in the pristine areas in the Antarctica. As a result, pathogens entering the furthest ecosystems in the Southern Hemisphere could be a serious threat for the future of wildlife. Therefore, it is essential to adopt biosecurity measures to limit the human impacts in the Antarctica", notes Jacob González-Solís.

Source: University of Barcelona [December 10, 2018]

Dolphins in the northern Adriatic contain high levels of PCBs – highly toxic chemicals banned in the 1970s and 1980s – and are passing the pollutant to their young, according to new research led by a marine scientist at the University of St Andrews.

Credit: Tilen Genov/ University of St Andrews

An international team of researchers evaluated PCB and other organochlorine contaminants in bottlenose dolphins (Tursiops truncatus) living in the Gulf of Trieste (northern Adriatic Sea), the northernmost part of the Mediterranean Sea and one of the most human-impacted areas in the Mediterranean.

They found that, overall, 87.5% of dolphins had PCB concentrations above the toxicity threshold for the onset of physiological effects in marine mammals, while 65.6% had concentrations above the highest threshold published for marine mammals based on reproductive impairment in seals. Such high contaminant levels are of concern, particularly in combination with other threats to dolphins, including bycatch in fisheries, disturbance by boat traffic, and prey depletion.

The research, published in the journal Science of the Total Environment, involved Morigenos – Slovenian Marine Mammal Society (Slovenia), the Sea Mammal Research Unit at the University of St Andrews (UK), the Zoological Society of London's Institute of Zoology (UK), the Centre for Environment, Fisheries and Aquaculture Science (CEFAS, UK) and the Institute of Marine Sciences of the Italian National Research Council (Italy).

Credit: Genov et al, Morigenos – Slovenian Marine Mammal Society (Slovenia)

Tilen Genov, lead author of the study and a Ph.D. student at the University of St Andrews, said:

"We have been studying these dolphins for over 16 years, so we know most of them well. Through long-term re-sighting histories of identified individuals, we were able to link PCB levels in individual dolphins to parameters such as sex, reproductive output and social group membership.

"The research showed that males have significantly higher pollutant concentrations than females. This is because females offload a substantial amount of their toxicological burden to their young through gestation and lactation.

Credit: Tilen Genov/ University of St Andrews

"That is also why females that have not yet had calves had significantly higher concentrations than those that had previously produced at least one calf. Such results are expected based on our knowledge of mammal physiology, but it is not very common to demonstrate this phenomenon in wild whales and dolphins."

Dr. Paul Jepson, co-author of the study and specialist wildlife veterinarian at the Zoological Society of London's Institute of Zoology, said:

"This is another study showing high or very high levels of a very toxic and persistent pollutant – PCBs – in European dolphins. PCBs have the ability to cause diseases like cancer and can also suppress reproduction."

Source: University of St Andrews [December 10, 2018]

New NASA research has found that increases in the rate at which Arctic sea ice grows in the winter may have partially slowed down the decline of the Arctic sea ice cover.

The sun setting over the Arctic sea ice pack, as observed during the Beaufort Gyre Exploration Project in October 2014 [Credit: NASA/Alek Petty]

As temperatures in the Arctic have warmed at double the pace of the rest of the planet, the expanse of frozen seawater that blankets the Arctic Ocean and neighboring seas has shrunk and thinned over the past three decades. The end-of-summer Arctic sea ice extent has almost halved since the early 1980s. A recent NASA study found that since 1958, the Arctic sea ice cover has lost on average around two-thirds of its thickness and now 70 percent of the sea ice cap is made of seasonal ice, or ice that forms and melts within a single year.

But at the same time that sea ice is vanishing quicker than it has ever been observed in the satellite record, it is also thickening at a faster rate during winter. This increase in growth rate might last for decades, a new study accepted for publication in Geophysical Research Letters found.

This does not mean that the ice cover is recovering, though. Just delaying its demise.

"This increase in the amount of sea ice growing in winter doesn't overcome the large increase in melting we've observed in recent decades," said Alek Petty, a sea ice scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study. "Overall, thickness is decreasing. Arctic sea ice is still very much in decline across all seasons and is projected to continue its decline over the coming decades. "

Petty and his team used climate models and observations of sea ice thickness from the European Space Agency's CryoSat-2 satellite to explore sea ice growth variability across the Arctic. The climate model results compared well both with CryoSat-2's measurements and the results of another commonly used Arctic sea ice model, giving the authors confidence in the climate model's ability to capture Arctic sea ice variability.

"The global climate model seems to do a good job of capturing the Arctic sea ice state and shows that most of the thickness change in the central Arctic is from thermodynamics, that is, ice formation and ice melt, although around the Arctic sea ice edge dynamics, which is ice transport, can play a bigger role," Petty said.

These model simulations showed that in the 1980s, when Arctic sea ice was on average 6.6 feet thick in October, about 3.3 extra feet of ice would form over the winter. That rate of growth has increased and may continue to do so for several more decades in some regions of the Arctic; in the coming decades, we could have an ice pack that would on average be only around 3.3 feet thick in October, but could experience up to 5 feet of ice growth over the winter.

It seems counterintuitive: how does a weakening ice cover manage to grow at a faster rate during the winter than it did when the Arctic was colder and the ice was thicker and stronger?

"Our findings highlight some resilience of the Arctic sea ice cover," Petty said. "If we didn't have this negative feedback, the ice would be declining even faster than it currently is. Unfortunately, the positive feedback loop of summer ice melt and increased solar absorption associated with summer ice melting still appears to be dominant and continue to drive overall sea ice declines."

Nonetheless, the increased rate of sea ice thickening in winter has other implications. As ice forms at the ocean surface, it releases a lot of the salty and dense water from which it originated, which sinks and increases the mixing of waters in the upper ocean. The more ice formation that takes place, the more mixing we expect to see in the upper ocean. Increases in this ice formation and mixing during winter may help mitigate the strong freshening of the Arctic Ocean's surface waters that has been observed in recent decades due to increased summer melt.

"This is altering the seasonal balance and the salinity distribution of the upper ocean in the Arctic; it's changing when we have fresh water, when we have salty water and how deep and seasonal that upper oceanic mixed layer is," Petty said. "And that's all going to mean that local micro-organisms and ecosystems have to adapt to these rapidly evolving conditions."

Petty's projections found that, by the middle of the century, the strong increases in atmospheric and oceanic temperatures will outweigh the mechanism that allows ice to regrow faster, and the Arctic sea ice cover will decline further. The study predicted that the switch will happen once the sea ice is less than 1.6 feet thick at the beginning of winter, or its concentration -the percentage of an area that is covered in sea ice- is less than 50 percent.

"This negative feedback mechanism increasing ice growth is unlikely to be sufficient in preventing an ice-free Arctic this century," Petty and his colleagues concluded.

Author: Maria-José Viñas | Source: NASA's Goddard Space Flight Center [December 06, 2018]

Surface melting across Greenland's mile-thick ice sheet began increasing in the mid-19th century and then ramped up dramatically during the 20th and early 21st centuries, showing no signs of abating, according to new research published in the journal Nature. The study provides new evidence of the impacts of climate change on Arctic melting and global sea level rise.

Large rivers form on the surface of Greenland each summer, rapidly moving meltwater from the ice sheet to the ocean [Credit: Sarah Das, Woods Hole Oceanographic Institution]

"Melting of the Greenland Ice Sheet has gone into overdrive. As a result, Greenland melt is adding to sea level more than any time during the last three and a half centuries, if not thousands of years," said Luke Trusel, a glaciologist at Rowan University's School of Earth & Environment and former post-doctoral scholar at Woods Hole Oceanographic Institution, and lead author of the study. "And increasing melt began around the same time as we started altering the atmosphere in the mid-1800s."

"From a historical perspective, today's melt rates are off the charts, and this study provides the evidence to prove this" said Sarah Das, a glaciologist at Woods Hole Oceanographic Institution (WHOI) and co-author of the study. "We found a fifty percent increase in total ice sheet meltwater runoff versus the start of the industrial era, and a thirty percent increase since the 20th century alone."

Ice loss from Greenland is one of the key drivers of global sea level rise. Icebergs calving into the ocean from the edge of glaciers represent one component of water re-entering the ocean and raising sea levels. But more than half of the ice-sheet water entering the ocean comes from runoff from melted snow and glacial ice atop the ice sheet. The study suggests that if Greenland ice sheet melting continues at "unprecedented rates" -- which the researchers attribute to warmer summers -- it could accelerate the already fast pace of sea level rise.

"Rather than increasing steadily as climate warms, Greenland will melt increasingly more and more for every degree of warming. The melting and sea level rise we've observed already will be dwarfed by what may be expected in the future as climate continues to warm," said Trusel.


To determine how intensely Greenland ice has melted in past centuries, the research team used a drill the size of a traffic light pole to extract ice cores from the ice sheet itself and an adjacent coastal ice cap, at sites more than 6,000 feet above sea level. The scientists drilled at these elevations to ensure the cores would contain records of past melt intensity, allowing them to extend their records back into the 17th century. During warm summer days in Greenland, melting occurs across much of the ice sheet surface. At lower elevations, where melting is the most intense, meltwater runs off the ice sheet and contributes to sea level rise, but no record of the melt remains. At higher elevations, however, the summer meltwater quickly refreezes from contact with the below-freezing snowpack sitting underneath. This prevents it from escaping the ice sheet in the form of runoff. Instead, it forms distinct icy bands that stack up in layers of densely packed ice over time.

The core samples were brought back to ice core labs at the U.S. National Science Foundation Ice Core Facility in Denver, Colo., WHOI in Woods Hole, Mass., Wheaton College in Norton, Mass., and the Desert Research Institute in Reno, Nev. where the scientists measured physical and chemical properties along the cores to determine the thickness and age of the melt layers. Dark bands running horizontally across the cores, like ticks on a ruler, enabled the scientists to visually chronicle the strength of melting at the surface from year to year. Thicker melt layers represented years of higher melting, while thinner sections indicated years with less melting.

Combining results from multiple ice cores with observations of melting from satellites and sophisticated climate models, the scientists were able to show that the thickness of the annual melt layers they observed clearly tracked not only how much melting was occurring at the coring sites, but also much more broadly across Greenland. This breakthrough allowed the team to reconstruct meltwater runoff at the lower-elevation edges of the ice sheet -- the areas that contribute to sea level rise.

Study lead author and WHOI post-doc Dr. Luke Trusel (now at Rowan University) takes field measurements of a section of ice core from Greenland before packing it for transport home [Credit: Sarah Das, Woods Hole Oceanographic Institution]

Ice core records provide critical historical context because satellite measurements -- which scientists rely on today to understand melting rates in response to changing climate -- have only been around since the late 1970s, said Matt Osman, a graduate student in the MIT-WHOI Joint Program and co-author of the study.

"We have had a sense that there's been a great deal of melting in recent decades, but we previously had no basis for comparison with melt rates going further back in time," he said. "By sampling ice, we were able to extend the satellite data by a factor of 10 and get a clearer picture of just how extremely unusual melting has been in recent decades compared to the past."

Trusel said the new research provides evidence that the rapid melting observed in recent decades is highly unusual when put into a historical context.

"To be able to answer what might happen to Greenland next, we need to understand how Greenland has already responded to climate change," he said. "What our ice cores show is that Greenland is now at a state where it's much more sensitive to further increases in temperature than it was even 50 years ago."

One noteworthy aspect of the findings, Das said, was how little additional warming it now takes to cause huge spikes in ice sheet melting.

"Even a very small change in temperature caused an exponential increase in melting in recent years," she said. "So the ice sheet's response to human-caused warming has been non-linear." Trusel concluded, "Warming means more today than it did in the past."

Additional co-authors are: Matthew B. Osman, MIT/WHOI Joint Program in Oceanography; Matthew J. Evans, Wheaton College; Ben E. Smith, University of Washington; Xavier Fettweis, University of Leige; Joseph R. McConnell, Desert Research Institute; and Brice P. Y. Noël and and Michiel R. van den Broeke Utrecht University.

This research was funded by the US National Science Foundation, institutional support from Rowan University and Woods Hole Oceanographic Institution, the US Department of Defense, the Netherlands Organization for Scientific Research, the Netherlands Earth System Science Center, and the Belgian National Fund for Scientific Research.

Source: Woods Hole Oceanographic Institution [December 05, 2018]

Global carbon emissions are set to hit an all-time high in 2018 - according to researchers at the University of East Anglia (UEA) and the Global Carbon Project.

A coal-fired power plant in Bergheim. Germany. Coal use in power stations is a major source of CO2 emissions [Credit: EPA-EFE]

A projected rise of more than 2 per cent has been driven by a solid growth in coal use for the second year in a row, and sustained growth in oil and gas use.

The news is a further call to action for governments at the UN Climate Change Conference (COP 24) in Katowice this week.

But the research team say energy trends are changing and that there is still time to address climate change if efforts to curb carbon emissions rapidly expand in all sectors of the economy.

The new data for 2018, published today simultaneously in the journals Nature, Earth System Science Data and Environmental Research Letters, reveals that global emissions from burning fossil fuels are expected to reach 37.1 billion tonnes of CO2 in 2018.

CO2 emissions have now risen for a second year, after three years of little-to-no growth from 2014 to 2016. The rise this year is projected at 2.7 per cent (+1.8 to +3.7 per cent). In 2017 it was 1.6 per cent.

The 10 biggest emitters in 2018 are China, the US, India, Russia, Japan, Germany, Iran, Saudi Arabia, South Korea, and Canada. The EU as a whole region of countries ranks third.

Lead researcher Prof Corinne Le Quéré, Director of the Tyndall Centre for Climate Change Research and Professor of Climate Change Science and Policy at UEA, said: "We are seeing a strong growth of global CO2 emissions once again.

"Emissions need to peak and rapidly decrease to address climate change. With this year's growth in emissions, it looks like the peak is not yet in sight.

"To limit global warming to the Paris Agreement goal of 1.5°C, CO2 emissions would need to decline by 50 per cent by 2030 and reach net zero by around 2050. We are a long way from this and much more needs to be done because if countries stick to the commitments they have already made, we are on track to see 3°C of global warming.

"This year we have seen how climate change can already amplify the impacts of heatwaves worldwide. The California wildfires are just a snapshot of the growing impacts we face if we don't drive emissions down rapidly."

What is driving the rise?

This year's rising emission figures are largely due to solid growth in coal use, but coal still remains below its historical high in 2013. Coal use may soon exceed this 2013 peak if current growth continues.

Oil use is growing strongly in most regions, with a rise in emissions from cars and lorries, including in the US and Europe. Flights have also contributed to the oil rise. Gas use has grown almost unabated in recent years.

Prof Le Quéré said: "The growing global demand for energy is outpacing decarbonisation for now. This needs to change, and change quickly to address climate change.

"We need strong policy and economic support for rapid deployment of low carbon technologies to cut emissions across the energy and transport sectors, from buildings and from industry.

Global carbon emissions are set to hit an all-time high in 2018 -- according to researchers at the University of East Anglia and the Global Carbon Project. A projected rise of more than 2 per cent has been driven by a solid growth in coal use for the second year in a row, and sustained growth in oil and gas use [Credit: Global Carbon Project]

"Energy trends are changing rapidly, with coal use decreasing in many parts of the world and still below its 2013 level globally, and an explosion in wind and solar energy. But while renewables are rising fast, it is not yet enough to reverse global emissions trends.

"The rapid actions needed to address climate change also need to be fair to all generations," she added.

Dr Glen Peters, a Research Director at the CICERO Center for International Climate Research in Oslo, who led the emissions analysis, said: "Global commitments made in Paris in 2015 to reduce emissions are not yet being matched by proportionate actions.

"Despite rapid growth in low carbon technologies such as solar and wind power, electric vehicles, and batteries, not nearly enough is being done to support policies that limit the amount of carbon dioxide that is put into the atmosphere.

"The rise in emissions in 2017 could be seen as a one-off, but the growth rate in 2018 is even higher, and it is becoming crystal clear the world is so far failing in its duty to steer onto a course consistent with the goals set out in the Paris Agreement in 2015."

CO2 emissions from deforestation and other human activities on land contributed an additional 5 billion tonnes of CO2 this year, bringing total CO2 emissions to 41.5 billion tonnes of CO2. The global trends in those emissions are unclear due to large uncertainties in the data.

Concentrations of carbon dioxide (CO2) in the atmosphere are set to increase by around 2.3 parts per million on average in 2018 in response to continued CO2 emissions, to reach about 407 parts per million over the year. This is 45 per cent above pre-industrial levels. The rise of CO2 in the atmosphere is the main cause of climate change.

The good news

Countering rising global emissions are 19 countries where emissions have reduced and their economy has grown. Aruba, Barbados, the Czech Republic, Denmark, France, Greenland, Iceland, Ireland, Malta, the Netherlands, Romania, Slovakia, Slovenia, Sweden, Switzerland, Trinidad and Tobago, the UK, the US, and Uzbekistan have all decreased their emissions over the past decade (2008-2017).

Deployment of renewable energy worldwide is accelerating exponentially, with electricity generation growing at 15 per cent per year on average over the last decade. But this has not been enough to offset the growth in fossil energy because renewables are growing from a low base. This is changing rapidly.

Christiana Figueres, Mission 2020 campaign group leader and lead author of the Nature Commentary, said: "Global CO2 emissions must start to fall from 2020 if we are to meet the temperature goals of the Paris agreement, but this is within our grasp. We have already achieved things that seemed unimaginable just a decade ago.

"Exponential progress in key solutions is happening and on track to displace fossil fuels. Renewable energy technology costs have dropped by 80 per cent in a decade, and today, over half of all new energy generation capacity is renewable. Before 2015 many people thought the Paris Agreement was impossible, yet thousands of people and institutions made the shift from impossible to unstoppable. The same is true of decarbonizing the economy. Propelled by the pursuit of clean air, jobs and energy-independence among other benefits, the intrepid, collective efforts of young people, civil society, businesses, investors, cities and states are charting the course to net zero emissions by 2050."

How different countries compare

Almost all countries have contributed to the rise in global emissions, either through growth in emissions or through reductions that are slower than expected. China's emissions account for 27 per cent of the global total, having grown an estimated 4.7 per cent (+2 per cent to +7.4 per cent) in 2018 and reaching a new all-time high. The growth in emissions is linked to construction activity and economic growth, part of which may be due to temporary stimulus-driven credit growth. Energy from renewables is growing by 25 per cent per year, but from a low base.

Emissions in the US account for 15 per cent of the global total, and look set to have grown about 2.5 per cent (+0.5 per cent to +4.5 per cent) in 2018 after several years in decline. The new rise is due to robust growth in oil use of about 1.4 per cent, associated with an increase in car journeys, and gas of about 7.6 per cent. Emissions from coal use look set to have decreased by around -2.1 per cent in 2018, continuing a shift away from coal, with a 40 per cent decrease in CO2 emissions from coal since 2007, mainly towards gas, and more recently also towards renewables for power generation.

EU emissions account for 10 per cent of global emissions and a small decline of around -0.7 per cent is projected, well below the declines of ?2 per cent per year in the decade up to 2014. Estimated declines in coal and gas use due to the growth in renewable energy have been partially offset by a growth in oil use. The amount of fuel used for road transport and flights has surged by around 4 per cent in the EU. Overall EU emissions are still near or above their 2014 levels.

India's emissions, accounting for 7 per cent of the global total, have continued to grow by around 6.3 per cent, as their economy booms. Wind and solar are growing fast, albeit from a low base.

Emissions in the rest of the world, the remaining 42 per cent of global emissions, are expected to grow about 1.8 per cent (+0.5 per cent to +3.0 per cent) this year. The five countries contributing most to the rest-of-the-word growth in global emissions in the last decade are Saudi Arabia, Iran, Turkey, Iraq and South Korea.

Source: University of East Anglia [December 05, 2018]

With rapid efficiency, a mysterious parasite is seeking out and killing a giant species of clam found only in the Mediterranean Sea. Unless scientists can find a way of stopping it soon, they say the mollusk could go extinct.

A diver observes a pen shell on the seabed in the Aegean Sea [Credit: Yiannis Issaris/AP]

For thousands of years, the emblematic noble pen shell has been intrinsically connected to human civilization. The largest bivalve in the Mediterranean can grow to more than a meter (three feet) long and has provided food and one of the world’s rarest materials: sea silk spun from fibers it uses to secure itself to the seabed. The mollusk also contributes to clear water by filtering out organic particulates.

The pen shell, Pinna nobilis, has been on the European Union’s protected species list for decades because of overfishing, pollution and the destruction of its natural habitat, meaning any fishing is banned. But the ban is often poorly enforced, with the animal harvested for food or for its shell, which is used for decorative purposes.

A pen shell stands on the seabed of the Aegean Sea [Credit: Yiannis Issaris/AP]

The pen shells, which have a life span of several decades and take years to reach reproductive age, were already dying faster than they could be replaced. So the spread of the microscopic parasite, which first appeared in the western Mediterranean in late 2016 and was identified just this year as a new species, has alarmed experts.

Exactly how the parasite kills isn’t completely clear, although scientists have found it attacks the pen shell’s digestive system. The infected animal is also unable to close its shell, incapacitating its defense against predators. Once infected, death is almost certain.

Yiannis Issaris, marine ecologist and research associate at the Hellenic Center for Marine Research, holds a dead noble pen shell, or Pinna nobilis, in Anavyssos, south of Athens [Credit: Thanassis Stavrakis/AP]

“In less than a year it wiped out (the pen shell population of) the Spanish coast,” said Maria del Mar Otero of the International Union for Conservation of Nature.

Soon parts of France, Malta, Tunisia and Italy were affected. In recent weeks, tests confirmed the same parasite, Haplosporidium pinnae, is responsible for pen shell die-offs in parts of Greece, and researchers have reported mass mortality as far east as Turkey and Cyprus.

Pen shells stand on the seabed in the Aegean Sea [Credit: Yiannis Issaris/AP]

Scientists are now racing to understand how the parasite spreads and its life cycle — essential information for a successful rescue program. One theory is that it could be spreading through phytoplankton, the bivalve’s food source, but nobody knows for certain.

“We cannot be sure of anything at this point,” said Pantelis Katharios, senior researcher at the Institute of Marine Biology, Biotechnology and Aquaculture of the Hellenic Center for Marine Research, or HCMR.

A dead pen shell stands open in a seagrass meadow in the Aegean Sea's Saronic Gulf [Credit: Elena Becatoros]

“What we know now is that the Pinnas are dying, that the cause is this parasite, and we know that it’s spreading very, very rapidly,” he said. “And that is going to be a huge problem (for) the ecology and the balance of the ecosystem in the Mediterranean.”

Yiannis Issaris, marine ecologist at the HCMR’s Institute of Oceanography, initially noticed widespread pen shell death off the coast of Anavyssos, southeast of Athens, in mid-summer. He suspected the culprit could be the same one causing mortality in Spain — and testing proved him right.

A pen shell stands anchored in the seabed of the Aegean Sea [Credit: Yiannis Issaris/AP]

Now the question is how to tackle the outbreak.

“This is very fresh for the scientific community,” Issaris said. “We’re still at the stage of recording where it has spread to.”

Yiannis Issaris, marine ecologist and research associate at the Hellenic Center for Marine Research, takes measurements of a dead noble pen shell, or Pinna nobilis, in Anavyssos, south of Athens [Credit: Thanassis Stavrakis/AP]

Some parts of Greece still have healthy populations of the mollusks, he noted, whereas in other areas they have been wiped out.

Protecting the pen shell in its natural habitat — sandy seabeds or seagrass meadows — appears “difficult to impossible,” Issaris said, particularly without knowing how the parasite spreads. In Spain, some healthy individuals were moved to aquariums.

Yiannis Issaris, marine ecologist and research associate at the Hellenic Center for Marine Research, takes measurements of a dead noble pen shell, or Pinna nobilis, in Anavyssos, south of Athens [Credit: Thanassis Stavrakis/AP]

Although tests are pending in some Mediterranean countries witnessing mass die-offs, experts have little doubt what the results will show.

“It’s very, very, very likely” to be the same parasite, Otero said. “There’s almost no question.”

Christina Pavloudi, foreground, post-doctoral researcher at the Hellenic Center for Marine Research laboratory on the Greek island of Crete, and Georgia Sarafidou, a student at the same facility, carry out tests on samples of noble pen shells stricken by a new parasite [Credit: Thanassis Stavrakis/AP]

One thing’s clear: the parasite is very particular in its choice of victim. A smaller, related species, the Pinna rudis, which also exists outside the Mediterranean, is unaffected.

“We don’t know how it has appeared in the Mediterranean... We only know that it causes mortality only in the Pinna nobilis,” Issaris said.

Yiannis Issaris, marine ecologist and research associate at the Hellenic Center for Marine Research, holds a dead noble pen shell, or Pinna nobilis, in Anavyssos, south of Athens [Credit: Thanassis Stavrakis/AP]

In the clear, shallow waters south of the Greek capital, dozens of dead pen shells lie scattered in a seagrass meadow, testament to the devastation.

Peering through a microscope at the tissue of an infected individual in his office in Crete, Katharios points out the culprit: small, oval-shaped parasites spread throughout the sample.

Scientists are puzzling over why an organism would be so lethal to the very species it depends on for its own survival.

Pantelis Katharios, senior researcher at the Institute of Marine Biology, Biotechnology and Aquaculture of the Hellenic Center for Marine Research on the Greek island of Crete, checks microscope imaging of a new parasite killing  the noble pen shell, or Pinna nobilis [Credit: Elena Becatoros]

“Normally parasites in nature do not have any benefit from harming the host, because they depend on the host,” Katharios explained. “But once in a while we may come across incidents like this, where we have massive mortalities.”

This could just be a natural phenomenon in which the parasite will eventually be wiped out along with its host, he said. Another possibility is that it originated in a different species and for some reason jumped to the pen shell. A third is that the pen shell’s immune system has been compromised by factors such as pollution, climate change or water temperature fluctuations.

“It’s extremely, extremely difficult to find the truth at this stage,” Katharios said.

Author: Elena Becatoros | Source: Associated Press [December 04, 2018]