Many of its brands — and commercials — may be iconic, from Meow Mix to Alpo, but the fact is that the pet food industry is a relatively new business. For millennia, cats and dogs were simply fed unwanted table scraps. Go to a timeless fish market like the Besiktas in Istanbul, and the chances are high that visitors will see a fishmonger feeding a feline the day’s scraps. Wander through the timeless Central Market in Athens and observers will watch the same thing, only with tidbits of beef and lamb.

Fast forward to the post-World War II era, however, and it was then that many food companies saw the benefits of marketing formulated pet foods to dog and cat owners. Growing affluence and the demand for convenience together inspired companies including General Foods, Nabisco and Purina (now owned by Nestlé) to enter the pet food sector. The profit margins were huge, as food waste that previously would have been discarded was recycled into what quickly became a lucrative new business.

Around 252 million years ago, life on Earth collapsed in spectacular and unprecedented fashion, as more than 96 percent of marine species and 70 percent of land species disappeared in a geological instant. The so-called end-Permian mass extinction ­— or more commonly, the “Great Dying” — remains the most severe extinction event in Earth’s history.

This Saturday at a conference in Quebec, Canada an international research team will present the first online data portal on global permafrost. In the Global Terrestrial Network for Permafrost researchers first collect all the existing permafrost temperature and active thickness layer data from Arctic, Antarctic and mountain permafrost regions and then make it freely available for download. This new portal can serve as an early warning system for researchers and decision-makers around the globe. A detailed description of the data collection is published today in an open access article on the Earth System Science Data portal.

Although the world's permafrost is one of the most important pieces in Earth's climate-system puzzle, to date it has been missing in most climate models. The reason: data on temperature and the active layer thickness were neither comprehensive nor were they available in a standard format suitable for modelling. With the new Global Terrestrial Network for Permafrost (GTN-P), scientists from 25 countries have now filled this gap in the data.

Researchers from the Arctic Research Programme, managed at British Antarctic Survey, have shown for the first time that phytoplankton (plant life) in remote ocean regions can contribute to rare airborne particles that trigger ice formation in clouds.

Results published today in the journal Nature show that the organic waste from life in the oceans, which is ejected into the atmosphere along with sea spray from breaking waves, stimulates cloud droplets to freeze into ice particles. This affects how clouds behave and influence global climate, which is important for improved projections of future climate change.

Like the leaves of New England maples, phytoplankton, the microalgae at the base of most oceanic food webs, photosynthesize when exposed to sunlight. In the process, they absorb carbon dioxide from the atmosphere, converting it to carbohydrates and oxygen. Many phytoplankton species also release dimethyl sulfide (DMS) into the atmosphere, where it forms sulfate aerosols, which can directly reflect sunlight or increase cloud cover and reflectivity, resulting in a cooling effect. The ability of phytoplankton to draw planet-warming carbon dioxide (CO2) from the atmosphere and produce aerosols that promote further cooling has made ocean fertilization — through massive dispersal of iron sulfite and other nutrients that stimulate phytoplankton growth — an attractive geoengineering method to reduce global warming.

For 25 years, methodical research by scientists has investigated the effects of the Exxon Valdez oil spill in 1989 on Alaskan communities and ecosystems. A new study released today into the effects of the 1989 Exxon Valdez oil spill in Alaska shows that embryonic salmon and herring exposed to very low levels of crude oil can develop hidden heart defects that compromise their later survival, indicating that the spill may have had much greater impacts on spawning fish than previously recognized.

The herring population crashed four years after the spill in Prince William Sound and pink salmon stocks also declined, but the link to the oil spill has remained controversial. The new findings published in the online journal Scientific Reports suggest that the delayed effects of the spill may have been important contributors to the declines.

Sea level rise poses one of the biggest threats to human systems in a globally warming world, potentially causing trillions of dollars' worth of damages to flooded cities around the world. As surface temperatures rise, ice sheets are melting at record rates and sea levels are rising.

But there may be some good news amid the worry. Sea levels may not rise as high as assumed.

Sometimes it pays to have big, bad neighbors. Weighing in at about 3 grams, black-chinned hummingbirds (Archilochus alexandri) can do little but stand by and watch Mexican jays 40 times their weight chow down on their eggs. So in the mountains of southeastern Arizona, the hummers have learned to build their nests near goshawk and Cooper’s hawk nests (Accipiter gentilis and Accipiter cooperii). Almost five times bigger than the jays (Amphelocoma wollweberi), the hawks enjoy these birds for lunch. So to avoid hawks swooping down and surprising them, the jays only forage above the hawks’ nests. Thus a cone-shaped safe zone exists below the 20-meter-high hawk nests, extending out about 100 meters, researchers report today in Science Advances. Of 342 hummer nests studied over three years, 80% were near hawk nests—and for good reason.

Biologists at the University of York have taken an important step in making it possible to clean millions of hectares of land contaminated by explosives.

Trees in cities throughout the UK could be significantly improving the quality of the air we breathe by decreasing pollution levels for pedestrians, researchers from the University of Leicester have revealed.