Clean-tech visionary Elon Musk first unveiled his idea for a high-speed ground transport system called Hyperloop back in 2013. The concept — in which passengers are transported in magnet-propelled capsules at more than 750 miles per hour — was quickly dismissed by many as a pipe-dream.

But, while most of us weren’t paying attention, a handful of private companies have been quietly working to make Musk’s vision a reality. Now two of these firms (both unaffiliated with the Tesla and SpaceX CEO) say they are ready to begin testing the technology.

Many people will see the snow currently blanketing much of the U.S. Eastern Seaboard as a nuisance coating sidewalks and roads. Others are celebrating it as an excuse to spend the day swooshing down a hill.

As for me, I like to think of snow as food.

Growing up in Missouri, I consumed as much snow ice cream as possible from November to March. Each time the winter sky let loose, I caught a bowl of fresh flakes. My grandmother mixed raw eggs, cream and sugar and poured it over top.

Snow is one of the first "wild" foods small humans learn to forage. And this time of year it's both free and plentiful to many.

While the effects of power plant emissions, vehicle exhaust and other manmade aerosols on air quality and public health are well-known, their impact on the climate is not completely understood. Scientists have shown that aerosols can lower surface temperatures either directly, by reflecting sunlight skyward, or indirectly, by increasing the reflectivity of clouds, but until now have not figured out the role these airborne particles play in shaping the distribution of rain and snowfall around the world.

Scientists are raising serious concerns about the future of whales and dolphins in European waters who are continuing to suffer from the effects of toxic chemicals that were banned decades ago, but continue to linger in the environment.

According to a new study led by the Zoological Society of London (ZSL), which was just published in the journal Scientific Reports, whales and dolphins in Europe  have been found to have some of the highest levels of polychlorinated byphenyls (PCBs) in the world.

Burning down forests in Africa and South-East Asia causes ozone pollution in the air as far as the western Pacific Ocean, researchers say, calling for revision of global climate models to reflect their findings.

In a paper published in Nature Communications last week (13 January), the scientists say their data contradicts earlier theories on the origins of ozone-rich air parcels above the tropical western Pacific, which were thought to descend naturally from a higher atmospheric layer.

A new analysis of ice-core climate data, archeological evidence and ancient pollen samples strongly suggests that agriculture by humans 7,000 years ago likely slowed a natural cooling process of the global climate, playing a role in the relatively warmer climate we experience today.

A study detailing the findings is published online in a recent edition of the journal Reviews of Geophysics, published by the American Geophysical Union.

“Early farming helped keep the planet warm,” said William Ruddiman, a University of Virginia climate scientist and lead author of the study, who specializes in investigating ocean sediment and ice-core records for evidence of climate fluctuations.

A dozen years ago, Ruddiman hypothesized that early humans altered the climate by burning massive areas of forests to clear the way for crops and livestock grazing. The resulting carbon dioxide and methane released into the atmosphere had a warming effect that “cancelled most or all of a natural cooling that should have occurred,” he said.

That idea, which came to be known as the “early anthropogenic hypothesis” was hotly debated for years by climate scientists, and is still considered debatable by some of these scientists. 

The most efficient way to clean up ocean plastics and avoid harming ecosystems is to place plastic collectors near coasts, according to a new study.

Plastic floating in the oceans is a widespread and increasing problem. Plastics including bags, bottle caps and plastic fibres from synthetic clothes wash out into the oceans from urban rivers, sewers and waste deposits.

A UC Davis scientist flying in a pollution-detecting airplane provided the first, and so far only, estimates of methane emissions spewing from the Aliso Canyon Natural Gas Storage Facility in Southern California since the leak began on Oct. 23, 2015.

Those estimates were provided to the California Air Resources Board in November. Pilot and UC Davis project scientist Stephen Conley continues to measure emissions from the still uncontrolled leak, which has displaced thousands of residents in the affluent Porter Ranch neighborhood in northern Los Angeles. On Jan. 6, Gov. Jerry Brown declared a state of emergency in the community.

To date, Conley estimates that the leak has emitted nearly 80,000 tons of methane, or about 1,000 tons per day.

Last week, the California Air Resources Board (CARB) said “no deal” to Volkswagen’s proposal to buy back some of the vehicles that were outfitted with cheat devices. According to CARB, the plan, which would see the recall of only a fraction of the 600,000 U.S. cars affected in the latest VW scandal, does “not adequately address overall impacts on vehicle performance, emissions and safety,” and would not fix the cars’ pollution problems quickly enough.

Scientists have shown that a process known as oxidative stress is at work during encounters between certain nanoparticles and immune cells, selectively modifying proteins on macrophages, a type of immune cell. The findings, by researchers at the Department of Energy's Pacific Northwest National Laboratory, were published in the journal ACS Nano.

While oxidative stress is a common way for cell damage to occur, the findings were a surprise in some ways.

"Oxidative stress is occurring selectively even at low levels of exposure to nanoparticles," said Brian Thrall, a nanotoxicology expert at PNNL and a corresponding author of the study. "We've demonstrated an approach that is sensitive enough to detect effects of nanoparticles on macrophages long before those cells die. This gives us the opportunity to understand the most sensitive cellular targets of oxidative stress and the pathways involved more completely than before.

"This is important information for understanding how nanoparticles can alter cell function and for beginning to identify functions that allow cells to adapt versus those that are potentially involved in adverse effects," Thrall added.