First Flower Seeds from Dinosaur Era Discovered

The world may never know if dinosaurs stopped to smell the flowers, but scientists have uncovered a few more clues about the ancient blossoms that grew alongside ankylosaurs

Various fruits and seeds of Early Cretaceous flowering plants, reconstructed from synchrotron radiation X-ray tomographic microscopy (SRXTM) scans.

 and iguanadons. Recently, researchers discovered tiny Cretaceous flower seeds dating back 110 million to 125 million years, the oldest-known seeds of flowering plants. These puny pips offer a glimpse into the biology powering the ancient predecessors of all modern flowers.

The seeds are miniscule — the largest was no more than 0.1 inch (2.5 millimeters) in diameter — and unusually well-preserved, in such good condition that their internal cell structures were still visible. For the first time, scientists were able to detect seed embryos, the part of the seed where a new plant grows and emerges, and food storage tissues surrounding them. These structures offered a rare glimpse into how the Cretaceous seeds grew, and how they compare with plants alive today.

Else Marie Friis, lead author of the study and professor emerita at the Swedish Museum of Natural History, has analyzed some of these fossil remains of angiosperms — flowering plants — preserved in soils in Portugal and North America. She and her colleagues used a relatively new visualization technique — synchrotron radiation X-ray tomographic microscopy (SRXTM), which allowed them to explore the delicate fossils without damaging or destroying them. They imaged 250 seeds spanning 75 different species (some were also different genera), revealing the embryos and nutrient structures inside the seeds in exquisite detail. 

Fossils of one of the oldest flowering plants on Earth date back to the early Cretaceous period, approximately 125 million to 130 million years ago. The ancient plant, Montsechia vidalii, lived underwater and is raising new questions about the planet's first flowering plants. [Read full story about the ancient plant fossils]

Aquatic plant

Montsechia vidalii had long shoots and small leaves and likely bloomed underwater. (Credit: David Dilcher, Indiana U

niversity)

Ancient blooms

The fossilized remains of Montsechia vidalii show long- and short-leaved forms of the flowering plant. (Credit: David Dilcher, Indiana University)
Fossilized remains

The intact fossil of the aquatic plant Montsechia vidalii that grew in freshwater lakes. (Credit: David Dilcher, Indiana University)
Underwater pollination

Researchers said the plant appears to have relied on water currents alone to move its pollen about. (Credit: David Dilcher, Indiana University)
Location and distribution

Montsechia vidalii fossils were found in what is now northeastern Spain. (Credit: David Dilcher, Indiana University)
Ancient find

The ancient plant is about 125 million to 130 million years old, and lived in the early Cretaceous period. (Credit: David Dilcher, Indiana University)

Just a nudge could collapse West Antarctic Ice Sheet, raise sea levels 3 meters

NASA/MARIA-JOSÉ VIÑAS

Two Antarctic ice shelves on the verge of collapsing—the Pine Island Glacier (shown) and the Thwaites Glacier—will cause the ultimate collapse of the entire West Antarctic Ice Sheet, a new study shows.

It won’t take much to cause the entire West Antarctic Ice Sheet to collapse—and once it starts, it won’t stop. In the last year, a slew of papers has highlighted the vulnerability of the ice sheet covering the western half of the continent, suggesting that its downfall is inevitable—and probably already underway. Now, a new model shows just how this juggernaut could unfold. A relatively small amount of melting over a few decades, the authors say, will inexorably lead to the destabilization of the entire ice sheet and the rise of global sea levels by as much as 3 meters.

Previous models have examined the onset of the collapse in detail. In 2014, two papers, one in Science and one in Geophysical Review Letters, noted that the Thwaites Glacier, which some scientists call the “weak underbelly” of the West Antarctic Ice Sheet, has retreated dramatically over the past 2 decades. Most Antarctic researchers chalk this up to warm seawater melting the floating ice shelves at their bases; seawater temperatures there have risen since the 1970s, in part because of global temperature increases. Right now, an underwater ledge is helping anchor the glacier in place. But when the glacier retreats past that bulwark, it will collapse into the ocean; then seawater will intrude and melt channels into the ice sheet, setting the juggernaut in motion.

Scientists agree that this is going to happen, says Eric Rignot of the University of California, Irvine, lead author of the Geophysical Review Letters paper. “The real central question is the time scale.”

But most models have focused on short-term timescales, decades or a few centuries at most, says Anders Levermann, a climate scientist at the Potsdam Institute for Climate Impact Research in Germany and co-author of the new paper. He and climate scientist Johannes Feldmann, also of the Potsdam climate center, wanted to examine how the destabilization would progress in the longer term, over hundreds to thousands of years. “The big question was how far [the instability] would reach inland,” Levermann says.

To study this, they ran computer simulations focusing on the dynamic forces that would act on the ice over time, from frozen inland ice to fast-flowing ice streams to floating ice shelves. They used the model first to simulate existing, observed subsurface melting within the Amundsen Sea, a region of West Antarctica that includes two vulnerable glaciers, Thwaites and the Pine Island Glacier. The model simulated current observations of enhanced, rapid melting until it recreated the current positions of the glaciers. Then they turned down the heat: They returned the model’s ocean and atmosphere conditions to those existing in the later 20th century, rather than the current 21st century conditions that have been causing rapid melting. “We wanted to show [how] it unfolds without us pushing it anymore,” Levermann says.

What they found was that local destabilization of the Amundsen Sea region of West Antarctica ultimately causes the entire ice sheet to fall into the ocean over several centuries to several thousands of years, gradually adding 3 meters to global sea levels, they report online today in the Proceedings of the National Academy of Sciences. The model shows that “there’s no holding back,” Levermann says: Just a few decades of melting leads to “thousands of years of ice motion.” More than 150 million people globally live within just 1 meter of the sea; in the United States, a sea level rise of 3 meters would inundate many of the East Coast’s largest cities, including New York and Miami.

One of the most startling results, he adds, was the knock-on effects of the melting. In an earlier study, the team found that the neighboring Filchner-Ronne and Ross ice shelves would not collapse on their own; the seafloor topography would keep them anchored in place and prevent the destabilizing inward rush of seawater. But when the Amundsen Sea region is destabilized, the model showed, the entering seawater was able to erode those ice shelves from the inside out.

“This paper does confirm what we hypothesized, that knocking out the Pine Island Glacier and Thwaites takes down the rest of the West Antarctic Ice Sheet,” says Ian Joughin, a glaciologist at the University of Washington, Seattle, who co-authored last year’s Sciencepaper. He adds, however, that the model’s weakness is its resolution; it shows the destabilization of the glaciers occurring roughly 60 years from now, whereas present observations suggest that collapse is already underway. As a result, Joughin says, the model’s time scale for the collapse is probably too long. “It’s more likely measured in centuries rather than millennia.”

Indeed, “the jury is still out” on whether Feldmann and Levermann’s study got the time scale right, Rignot says. The long-term evolution of an ice sheet “is a very complex modeling problem. Some of the variables controlling the models are not all that well known,” he adds, including forces such as winds, ocean circulation, and how icebergs calve. “There is not a model out there that is getting it right, because they all have caveats. I think the discussion is ongoing, and is only going to be more interesting with time.”

Posted in Climate, Environment

Underlying causes of Delhi’s air pollution problems

A new study "Air Pollution Challenges for developing megacities like Delhi" published today inAtmospheric Environment has described how Delhi suffers a toxic blend of geography, growth, poor energy sources and unfavourable weather that perpetuates and propagates its dangerously high levels of air pollution.

A team of researchers led by the University of Surrey assessed how Delhi's landscape, weather, energy consumption culture, and growing urban population combines to elevate concentrations of air pollutants, including ultrafine particles, the most harmful to human health.

"Air pollution has been placed in the top ten health risks faced by human beings globally. Delhi has the dubious accolade of being regularly cited as the most polluted city in the world, with air pollution causing thousands of excess deaths in a year in this growing megacity, explained Dr Prashant Kumar of the University of Surrey.

" Whilst it might be easy to blame this on increased use of vehicles, industrial production or a growing population, the truth is that Delhi is a toxic pollutant punchbowl with myriad ingredients, all which need addressing in the round."

Delhi is one of the largest population centres in the world. Classed as the world's fifth 'megacity', it has a population of 25.8 million, which continues to grow. With this growth, our research predicted that the number of road vehicles will increase from 4.7 million in 2010 to nearly 26 million by 2030. Total energy consumption in Delhi has risen 57% from 2001 to 2011.

As a landlocked megacity Delhi has limited avenues for flushing polluted air out of the city. Coastal megacities such as Mumbai have at least a chance to 'replace' polluted air with relatively unpolluted sea breezes, whereas Delhi's surrounding regions are sometimes even more polluted than the city. For example, most of the brick kilns used for making bricks are not located in the city, but in predominantly upwind surrounding industrial areas.

These outside pollutants can be attributed to use of low-quality fuels such as raw wood, agricultural and plastic waste in industrial settings, cow dung for cooking stoves and widespread use of diesel generators due to unreliable infrastructure. These sources release fine particle pollutants, the most dangerous to human health.

In Delhi fine particle pollution rates are ten times higher than that of Chennai, which has ten times more cars but is coastally located, without the surrounding industrial areas.

Coupled with Delhi's densely packed architecture, and varying building heights the 'breathability' of the city is inhibited by its weather conditions. The city's decreasing temperature (attributed to the effects of pollution) draws outside polluted air into the city centre, whilst windy, dusty conditions during summer exacerbate this problem.

"The picture of Delhi's pollution problem is complicated and is aggravated by some factors that are out of human control," continued Dr Kumar. "However, in this growing city it is important that the population is protected in whatever ways they can be from health-endangering pollutants. Simple remedies such as 'greening' unpaved roadside areas through a natural or artificial grass canopy could possibly help in limiting coarse dust particles during dry and windy seasons. Natural measures, such as the development of wetlands and trees are also effective."

"There is also a cultural context here. Even the best science and technology will not succeed in reducing emissions and improving air quality if it is not considered in a broader framework of economic development of the country, rising awareness of public health risks and a change in attitudes and regulation towards poor quality fuels. It is a complicated, pick-and-mix of problems that will prove difficult to combat without innovative, encompassing and quick action."

Storage advance may boost solar thermal energy potential

An advance in the storage of concentrated solar thermal energy may reduce reduce its cost and make it more practical for wider use.

Credit: Graphic by Kelvin Randhir, courtesy of the University of Florida

Engineers at Oregon State University have identified a new approach for the storage of concentrated solar thermal energy, to reduce its cost and make it more practical for wider use.

The advance is based on a new innovation with thermochemical storage, in which chemical transformation is used in repeated cycles to hold heat, use it to drive turbines, and then be re-heated to continue the cycle. Most commonly this might be done over a 24-hour period, with variable levels of solar-powered electricity available at any time of day, as dictated by demand.

The findings have been published in ChemSusChem, a professional journal covering sustainable chemistry. The work was supported by the SunShot Initiative of the U.S. Department of Energy, and done in collaboration with researchers at the University of Florida.

Conceptually, all of the energy produced could be stored indefinitely and used later when the electricity is most needed. Alternatively, some energy could be used immediately and the rest stored for later use.

Storage of this type helps to solve one of the key factors limiting the wider use of solar energy -- by eliminating the need to use the electricity immediately. The underlying power source is based on production that varies enormously, not just night and day, but some days, or times of day, that solar intensity is more or less powerful. Many alternative energy systems are constrained by this lack of dependability and consistent energy flow.

Solar thermal electricity has been of considerable interest because of its potential to lower costs. In contrast to conventional solar photovoltaic cells that produce electricity directly from sunlight, solar thermal generation of energy is developed as a large power plant in which acres of mirrors precisely reflect sunlight onto a solar receiver. That energy has been used to heat a fluid that in turn drives a turbine to produce electricity.

Such technology is appealing because it's safe, long-lasting, friendly to the environment and produces no greenhouse gas emissions. Cost, dependability and efficiency have been the primary constraints.

"With the compounds we're studying, there's significant potential to lower costs and increase efficiency," said Nick AuYeung, an assistant professor of chemical engineering in the OSU College of Engineering, corresponding author on this study, and an expert in novel applications and use of sustainable energy.

"In these types of systems, energy efficiency is closely related to use of the highest temperatures possible," AuYeung said. "The molten salts now being used to store solar thermal energy can only work at about 600 degrees centigrade, and also require large containers and corrosive materials. The compound we're studying can be used at up to 1,200 degrees, and might be twice as efficient as existing systems.

"This has the potential for a real breakthrough in energy storage," he said.

According to AuYeung, thermochemical storage resembles a battery, in which chemical bonds are used to store and release energy -- but in this case, the transfer is based on heat, not electricity.

The system hinges on the reversible decomposition of strontium carbonate into strontium oxide and carbon dioxide, which consumes thermal energy. During discharge, the recombination of strontium oxide and carbon dioxide releases the stored heat. These materials are nonflammable, readily available and environmentally safe.

In comparison to existing approaches, the new system could also allow a 10-fold increase in energy density -- it's physically much smaller and would be cheaper to build.

The proposed system would work at such high temperatures that it could first be used to directly heat air which would drive a turbine to produce electricity, and then residual heat could be used to make steam to drive yet another turbine.

In laboratory tests, one concern arose when the energy storage capacity of the process declined after 45 heating and cooling cycles, due to some changes in the underlying materials. Further research will be needed to identify ways to reprocess the materials or significantly extend the number of cycles that could be performed before any reprocessing was needed, AuYeung said.

Other refinements may also be necessary to test the system at larger scales and resolve issues such as thermal shocks, he said, before a prototype could be ready for testing at a national laboratory.

Study of cloud cover in tropical Pacific reveals future climate changes

A new analysis using changes in cloud cover over the tropical Indo-Pacific Ocean showed that a weakening of a major atmospheric circulation system over the last century is due, in part, to increased greenhouse gas emissions. The findings from researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science provide new evidence that climate change in the tropical Pacific will result in changes in rainfall patterns in the region and amplify warming near the equator in the future.

"Our findings show that an increasing concentration of greenhouse gases leads to significant changes in atmospheric circulation and tropical rainfall patterns," said Katinka Bellomo, an alumna of the UM Rosenstiel School. "This study demonstrates that we can predict these changes in the Walker circulation from changes in cloud cover."

The UM Rosenstiel School researchers used historical observations of cloud cover as a proxy for wind velocity in climate models to analyze the Walker circulation, the atmospheric air flow and heat distribution in the tropic Pacific region that affects patterns of tropical rainfall. Their findings revealed a weakening and eastward shift of the Walker circulation over the last century due to greenhouse gas emissions. The analysis showed that changes in cloud cover can serve as a proxy in climate models for wind velocity in the atmosphere, which cannot be directly measured.

"This study makes innovative use of a decades old-dataset," said Amy Clement, professor of atmospheric science at the UM Rosenstiel School. "It is impressive that visual observations from the decks of ships transiting the Pacific Ocean over a half-century can tell us something so fundamental about climate change."

This new information can be incorporated into current climate models to predict future changes in the magnitude and pattern of the Walker Circulation due to increased greenhouse gas emissions. The study suggests that rainfall will decrease over Indonesia and in the western Pacific and increase over the central Pacific Ocean.

Read more on

http://www.sciencedaily.com/releases/2015/11/151104180534.htm

Climate change is moving mountains

Research points to strong interaction between climate shifts, increased internal movement in the North American St. Elias Mountain Range

Terminus of the Hubbard Glacier at Resurrection Bay. The ice front is about 300 feet high.

Credit: provided by UC's Eva Enkelmann

For millions of years global climate change has altered the structure and internal movement of mountain ranges, but the resulting glacial development and erosion can in turn change a mountain's local climate. The degree of this cause-and-effect relationship has never been clearly observed, until now.

Based on research led by University of Cincinnati geologist Eva Enkelmann in the St. Elias Mountain Range -- located along the Pacific coastal region of North America -- the way a mountain range moves and behaves topographically can also change and create its local climate by redirecting wind and precipitation. The repercussions of these changes can in turn, accelerate the erosion and tectonic seismic activity of that mountain range.

Based on her findings, Enkelmann shows clear evidence for a strong relationship between global and local climate change and a mountain's internal tectonic plate shifts and topographic changes.

Enkelmann, an assistant professor in the University of Cincinnati Department of Geology, was among several UC researchers and thousands of geoscientists from around the globe presenting their findings at the 2015 Annual Geological Society of America Meeting, Nov.1-4, in Baltimore.

This research also was published in July in the journal Geophysical Research Letters.

Moving Mountains

"To understanding how mountain structures evolve through geologic time is no quick task because we are talking millions of years," says Enkelmann. "There are two primary processes that result in the building and eroding of mountains and those processes are interacting."

Looking at the St. Elias Mountains in particular, Enkelmann notes how dry it is in the northern part of the mountain range. But the precipitation is very high in the southern area, resulting in more erosion and material coming off the southern flanks. So as the climate change influences the erosion, that can produce a shift in the tectonics. This has been suggested in earlier studies based on numerical and analytical models, however, it had not yet been shown to have occurred over geologic times in the real world.

Enkelmann synthesized several different data sets to show how a rapid exhumation occurred in the central part of the mountain range over four to two million years ago. This feedback process between erosion and internal tectonic shifting resulted in a mass of material moving up toward the surface very rapidly.

Enkelmann's model suggests that global climate shifts triggered a change in the rheology -- the way material behaves.

While Earth was much warmer millions of years ago, glaciers still existed in the high altitudes. However, 2.6 million years ago Earth experienced a shift to a colder climate and glaciation intensified. Existing glaciers grew larger, froze solid, covered the area and did not move.

Enkelmann says the glaciers today are wet-based and are moving, very aggressively eroding material around and out, and in the case of her observation, into the Gulf of Alaska. The tectonic forces (internal plates moving toward one another) continue to move toward Alaska, get pushed underneath and the sediment on top is piling up above the Yakutat plate.

Shake, Rattle and Roll

Adding to the already complex effects of climate change, these processes essentially work against each other.

The movement of glaciers can compete with the internal buildup and develop a feedback process that is very rapid and ferocious. Scientists have suggested that the Himalayas, European Alps and mountains in Taiwan were caused by the same competing reactions as those Enkelmann has observed in southeastern Alaska.

In Enkelmann's observation, the climate-driven erosion can influence the tectonics and change the motion of the rocks in that area. This makes studying the St. Elias Mountain Range particularly ideal because this area is very active tectonically, with strong glacial erosion. As an example, she cites the Great Alaskan Earthquake of 1964 -- the world's second largest earthquake recorded to date -- that also resulted in a tsunami.

"In 1899, there were two big earthquakes in a row, an 8.1 and an 8.2 magnitude, says Enkelmann pointing to a photo of the resulting shoreline lift that still stands today. "These earthquakes resulted in up to 14 meters of co-seismic uplift on the shore, so the shoreline basically popped up 14 meters (45 feet) and it happened immediately.

"Our biggest concern today is the continued potential for earthquakes that can also result in tsunamis," says Enkelmann.

Enkelmann appreciates the challenge of collecting samples here because this range has the highest peaks of any coastal mountain range and is only 20 kilometers from the Pacific Ocean, but she points out that it is a tough area to study because of the big ice sheets.

"So as geologists, we go to the area and take samples and do measurements in the field on the mountain ranges that stick out," says Enkelmann. "One approach is to sample the material that comes out of the glaciers that has transported the eroded sediment and analyze that sediment.

"By going to all of these individual glaciers, we can get a much better understanding of what has happened and what was moved on the entire mountain range."

Climate change: A wake-up call in the world of finance

As climate changes become impossible to dismiss, how does the mainstream investor community respond? Are financial decisions taking full account of risks and opportunities related to climate change, or is the topic still virtually ignored in financial decision-making?

The environmental effects of climate change in our modern world are increasingly convincing, and global leaders will gather soon in a major Summit to try to address the problem. As climate changes become impossible to dismiss, how does the mainstream investor community respond? Are financial decisions taking full account of risks and opportunities related to climate change, or is the topic still virtually ignored in financial decision-making? Paula DiPerna sets out new trends and momentum to answer these questions in her article, published in the current issue ofEnvironment: Science and Policy for Sustainable Development, "Wall Street Wakes Up: Sustainable Investment and Finance Going Mainstream."

The forthcoming Climate Summit in Paris in December comes after many years of global negotiations. During the 1992 United Nations Conference on Environment and Development, Heads of States committed their nations to improving environmental conditions and battling climate change. The result? DiPerna writes, "Some progress has been made, of course, but far too little, considering the thousands of person-hours spent in strategy sessions, conferences, and scenario building worldwide." Breakthroughs in environmental initiatives have been made, but an overall well-funded "reindustrialization and reemployment initiative" still remains unseen today. DiPerna suggests that a reason for the lag is for the failure to link environmental and economic questions in comprehensive fashion.

However, DiPerna cites new momentum among mainstream investors to take climate change issues into account, with new and strong interest by investors in reckoning with the fact that both the risks and costs of extreme weather events will continue to rise, with significant implications for economic stability. As more environmental information is accumulated, and the more climate change becomes irrefutable, the more relevant environmental reality becomes to economic well-being. And, DiPerna writes, mainstream investors have begun react to this connection. As more financial data is collected, the more sensible sustainable investments appear. Quite simply, DiPerna writes, "With more meaningful environmental thinking on Wall Street, climate change can be addressed and without that new thinking, climate change cannot be addressed."

Ultimately, green investments can change the landscape of our country, both socially and economically, and new thinking on Wall Street can help pave the way for these much-needed changes to occur. According to DiPerna, as a new generation of investors come into power, one can hope that a corner has been turned on Wall Street.