Mass Extinction

Algae and bacteria are normal parts of a healthy freshwater environment, but sometimes they can grow out of control and deplete the water of oxygen, creating ‘dead zones. This tends to happen with global warming, deforestation, and the rush of soil nutrients into waterways, which can feed microbes. All three of these factors are in play today, which is why we are probably seeing increases in toxic blooms already. Considering what’s happened in the past, that’s a disturbing sign.

According to soil, fossil, and geochemical data from the Sydney Basin, researchers think the spread of microbes in the wake of the Permian extinctionwas both a symptom of continental ecosystem collapse, and a cause of its delayed recovery.” Volcanic eruptions in the Permian first triggered an accelerated and sustained rise in greenhouse gas emissions. This caused higher global temperatures and sudden deforestation due to wildfires or drought.

Once the trees were gone, it wasn’t long before the structure of the soil began to erode, and its nutrients slipped into freshwater ecosystems. For more than three million years, Earth’s forests struggled to recover. The Sydney Basin was instead littered with lowland ecosystems that “were regularly inundated by stagnant, fresh/brackish waterbodies hosting thriving algal and bacterial populations“, the authors write. In turn, these persistent dead zones prevented the reestablishment of important carbon sinks, like peatlands, and slowed down climate and ecosystem recovery.

This major episode caused vast amounts of dust and sulfate aerosols to rise into the atmosphere, but compared to volcanic activity, the meteorite only caused a modest increase in atmospheric carbon dioxide and temperature, not a sustained one. As such, freshwater microbes only seemed to undergo a short-lived burst after the extinction event. Unfortunately, that’s very different from what occurred during the Permian extinction and what is happening today.

For instance, the researchers note that the “optimal temperature growth range” of these harmful algae in freshwater environments is 20-32 °C (68-89.6 °F). That range matches the estimated continental summer surface air temperatures for the region during the early Triassic. That range is what’s projected for mid-latitude continental summer surface air temperatures in 2100. Scientists are noticing other similarities, including an increase in forest fires and the subsequent destabilization of soils.

The other big parallel is that the increase in temperature at the end of the Permian coincided with massive increases in forest fires,” says geologist Chris Fielding, also from the University of Connecticut. “One of the things that destroyed whole ecosystems was fire, and we’re seeing that right now in places like California. One wonders what the longer-term consequences of events like that as they are becoming more and more widespread.

The good news is that this time many of the changes are in our control. The bad news is that whatever happens next is our own fault. “The end-Permian mass extinction event took four million years to recover from,” Fielding says. “That’s sobering.”

Source: https://www.nature.com/
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https://www.sciencealert.com/

U.N. climate change report sounds ‘code red for humanity’

Global warming is dangerously close to spiralling out of control, a U.N. climate panel said in a landmark report Monday, warning the world is already certain to face further climate disruptions for decades, if not centuries, to come.

Humans are “unequivocallyto blame, the report from the scientists of the Intergovernmental Panel on Climate Change (IPCC) said. Rapid action to cut greenhouse gas emissions could limit some impacts, but others are now locked in.

The deadly heat waves, gargantuan hurricanes and other weather extremes that are already happening will only become more severe.

https://www.reuters.com/

Microwave Air Plasmas Could Replace Fuel For Jet Propulsion

Humans depend on fossil fuels as their primary energy source, especially in transportation. However, fossil fuels are both unsustainable and unsafe, serving as the largest source of greenhouse gas emissions and leading to adverse respiratory effects and devastation due to global warming.

A team of researchers at the Institute of Technological Sciences at Wuhan University has demonstrated a  that uses microwave air plasmas for . They describe the engine in the journal AIP Advances.

The motivation of our work is to help solve the problems owing to humans’ use of fossil fuel combustion engines to power machinery, such as cars and airplanes,” said author Jau Tang, a professor at Wuhan University. “There is no need for fossil fuel with our design, and therefore, there is no carbon emission to cause greenhouse effects and global warming.

Beyond solid, liquid and gas, is the fourth state of matter, consisting of an aggregate of charged ions. It exists naturally in places like the sun’s surface and Earth’s lightning, but it can also be generated. The researchers created a plasma jet by compressing air into high pressures and using a microwave to ionize the pressurized air stream.

This method differs from previous attempts to create plasma jet thrusters in one key way. Other plasma jet thrusters, like NASA‘s Dawn space probe, use xenon plasma, which cannot overcome the friction in Earth’s atmosphere, and are therefore not powerful enough for use in air transportation. Instead, the authors’ plasma jet thruster generates the high-temperature, plasma in situ using only injected air and electricity.

The prototype plasma jet device can lift a 1-kilogram steel ball over a 24-millimeter diameter quartz tube, where the high-pressure air is converted into a by passing through a microwave ionization chamber. To scale, the corresponding thrusting pressure is comparable to a commercial airplane jet engine. By building a large array of these thrusters with high-power microwave sources, the prototype design can be scaled up to a full-sized jet. The authors are working on improving the efficiency of the device toward this goal. “Our results demonstrated that such a jet engine based on microwave air plasma can be a potentially viable alternative to the conventional fossil fuel jet engine,” Tang said.

Source: https://phys.org/

Commercial Nuclear Fusion Is Closer Than Ever

Nuclear fusion has been seen as the unattainable holy grail of clean energy for decades, but just in the last year it’s been seeming more and more within reach. As catastrophic climate change looms just over the horizon, the scientific community has galvanized to find more and better solutions to decarbonizing the global economy and replacing fossil fuels with a commercially viable, renewable, and green alternative. While much of the time and capital investment has flowed to more realistic options like solar and wind, some researchers have been dedicating their time and energy to capturing the energy of the sun here on earth–a silver bullet solution to global warming.

Conventional nuclear energy has also been hailed as a good, greenhouse gas emissions-free alternative to fossil fuels, but it has some major drawbacks, from the rare but catastrophic instance of nuclear meltdown to the industrial byproduct of nuclear waste. Nuclear fission, which is what nuclear energy plants currently use to create massive amounts of energy by splitting atoms, creates radioactive waste that remains hazardous for tens of thousands of years, if not longer.

The beauty of nuclear fusion is that, not only does it produce energy without creating radioactive waste since it can be achieved using only hydrogen or lithium, it’s also several times more powerful than fission. If we were ever able to harness it in a commercially viable way, it would mean the end of the oil-based economy as we know it. That’s why any news about nuclear fusion is major news. And in the past couple of years, there’s been a lot of new reports emerging about commercial nuclear fusion getting closer and closer to becoming a reality.

Last summer, reps from the International Thermonuclear Experimental Reactor (ITER), an intergovernmental project headquartered in the south of France, reported that they are a mere six and a half years away from achieving first plasma inside their tokamak–in other words: nuclear fusion by just 2025. Then, just a month later in August, 2019, Oak Ridge National Laboratory reported their own nuclear fusion breakthrough, which uses novel implementation of AI and supercomputing to successfully scale up nuclear fusion experiments and manage plasma.

Then, in October, the Los Alamos National Laboratory‘s Plasma Liner Experiment (PLX) unveiled a totally new approach to nuclear fusion, using the very science-fiction combination of plasma guns, magnets, and lasers. According to the American Physical Society, “the PLX machine combines aspects of both magnetic confinement fusion schemes (e.g. tokamaks) and inertial confinement machines like the National Ignition Facility (NIF). The hybrid approach, although less technologically mature than pure magnetic or inertial confinement concepts, may offer a cheaper and less complex fusion reactor development path.” That project is projected to be up and running by the end of this year.

And now, just this week, there are new and exciting claims about yet another novel fusion technology to vie for the best path toward commercial nuclear fusion. Startup HB11, which has its impetus at Australia’s University of New South Wales (UNSW), has pioneered a technology that uses lasers to encourage nuclear fusion between hydrogen and boron without the use of radioactive materials to facilitate the reaction. They’re so confident about the technology that they have already applied for and received patents in the United States, Japan, and China.

The secret,” reports Popular Mechanics, “is a cutting-edge laser and, well, an element of luck.” According to managing director Warren McKenzie, as quoted by New Atlas,You could say we’re using the hydrogen as a dart, and hoping to hit a boron, and if we hit one, we can start a fusion reaction.” While this may sound a little wishy-washy, McKenzie says that the approach is actually more precise than using extreme heat to facilitate fusion because the laser is directed, whereas heat-based reactors waste huge amounts of energy heating up the entire reactor and waiting for a collision to take place.

This means that this new technology–which is now four decades in the making–could make machines like the tokamak obsolete. UNSW emeritus professor Heinrich Hora’s design “seeks to not just compete with but replace entirely the extremely high-temperature current technologies to achieve fusion. These include fussy and volatile designs like the tokamak or stellarator, which can take months to get up to functionality and still spin out of working order in a matter of microseconds.”

Last but not least, two months ago, Newsweek reported that China is about to start operation on its “artificial sun“—a nuclear fusion device that produces energy by replicating the reactions that take place at the center of the sun. If successful, the device could edge scientists closer to achieving the ultimate goal of nuclear fusion: near limitless, cheap clean energy.

Source: https://www.newsweek.com/
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https://oilprice.com/

How To Recycle Greenhouse Gases into Fuel and Hydrogen

Scientists have taken a major step toward a circular carbon economy by developing a long-lasting, economical catalyst that recycles greenhouse gases into ingredients that can be used in fuel, hydrogen gas, and other chemicals. The results could be revolutionary in the effort to reverse global warming, according to the researchers. The study was published in Science.

Newly developed catalyst that recycles greenhouse gases into ingredients that can be used in fuel, hydrogen gas and other chemicals

We set out to develop an effective catalyst that can convert large amounts of the greenhouse gases carbon dioxide and methane without failure,” said Cafer T. Yavuz, paper author and associate professor of chemical and biomolecular engineering and of chemistry at KAIST (Korea).

The catalyst, made from inexpensive and abundant nickel, magnesium, and molybdenum, initiates and speeds up the rate of reaction that converts carbon dioxide and methane into hydrogen gas. It can work efficiently for more than a month.

This conversion is called ‘dry reforming’, where harmful gases, such as carbon dioxide, are processed to produce more useful chemicals that could be refined for use in fuel, plastics, or even pharmaceuticals. It is an effective process, but it previously required rare and expensive metals such as platinum and rhodium to induce a brief and inefficient chemical reaction.

Other researchers had previously proposed nickel as a more economical solution, but carbon byproducts would build up and the surface nanoparticles would bind together on the cheaper metal, fundamentally changing the composition and geometry of the catalyst and rendering it useless.

The difficulty arises from the lack of control on scores of active sites over the bulky catalysts surfaces because any refinement procedures attempted also change the nature of the catalyst itself,” Yavuz said.

The researchers produced nickel-molybdenum nanoparticles under a reductive environment in the presence of a single crystalline magnesium oxide. As the ingredients were heated under reactive gas, the nanoparticles moved on the pristine crystal surface seeking anchoring points. The resulting activated catalyst sealed its own high-energy active sites and permanently fixed the location of the nanoparticles — meaning that the nickel-based catalyst will not have a carbon build up, nor will the surface particles bind to one another.

It took us almost a year to understand the underlying mechanism,” said first author Youngdong Song, a graduate student in the Department of Chemical and Biomolecular Engineering at KAIST. “Once we studied all the chemical events in detail, we were shocked.”

The researchers dubbed the catalyst Nanocatalysts on Single Crystal Edges (NOSCE). The magnesium-oxide nanopowder comes from a finely structured form of magnesium oxide, where the molecules bind continuously to the edge. There are no breaks or defects in the surface, allowing for uniform and predictable reactions.

Our study solves a number of challenges the catalyst community faces,” Yavuz said. “We believe the NOSCE mechanism will improve other inefficient catalytic reactions and provide even further savings of greenhouse gas emissions.

Source: https://news.kaist.ac.kr/

Solar-driven Water Splitting Catalyst Produces Hydrogen

Engineers from Lehigh University (Bethlehem, Pennsylvania)  are the first to utilize a single enzyme biomineralization process to create a catalyst that uses the energy of captured sunlight to split water molecules to produce hydrogen. The synthesis process is performed at room temperature and under ambient pressure, overcoming the sustainability and scalability challenges of previously reported methods.

Solar-driven water splitting is a promising route towards a renewable energy-based economy. The generated hydrogen could serve as both a transportation fuel and a critical chemical feedstock for fertilizer and chemical production. Both of these sectors currently contribute a large fraction of total greenhouse gas emissions.

One of the challenges to realizing the promise of solar-driven energy production is that, while the required water is an abundant resource, previously-explored methods utilize complex routes that require environmentally-damaging solvents and massive amounts of energy to produce at large scale. The expense and harm to the environment have made these methods unworkable as a long-term solution.

Now a team of engineers at Lehigh have harnessed a biomineralization approach to synthesizing both quantum confined nanoparticle metal sulfide particles and the supporting reduced graphene oxide material to create a photocatalyst that splits water to form hydrogen. The team reported their results in an article entitled: “Enzymatic synthesis of supported CdS quantum dot/reduced graphene oxide photocatalysts” featured on the cover of the August 7 issue of Green Chemistry, a journal of the Royal Society of Chemistry. “Our water-based process represents a scalable green route for the production of this promising photocatalyst technology,” says Professor Steven McIntosh, who is also associate director of Lehigh’s Institute for Functional Materials and Devices.

Source: https://engineering.lehigh.edu/