Ocean circulation implicated in past abrupt climate changes

There was a period during the last ice age when temperatures in the Northern Hemisphere went on a rollercoaster ride, plummeting and then rising again every 1,500 years or so. Those abrupt climate changes wreaked havoc on ecosystems, but their cause has been something of a mystery. New evidence published this week in the leading journal Science shows for the first time that the ocean's overturning circulation slowed during every one of those temperature plunges - at times almost stopping.

"People have long supposed this link between overturning circulation and these abrupt climate events. This evidence implicates the ocean," said L. Gene Henry, the lead author of the study and a graduate student at Columbia University's Lamont-Doherty Earth Observatory.

Scientists observe first signs of healing in the Antarctic ozone layer

Scientists at MIT and elsewhere have identified the "first fingerprints of healing" of the Antarctic ozone layer, published today in the journal Science.

The team found that the September ozone hole has shrunk by more than 4 million square kilometers -- about half the area of the contiguous United States -- since 2000, when ozone depletion was at its peak. The team also showed for the first time that this recovery has slowed somewhat at times, due to the effects of volcanic eruptions from year to year. Overall, however, the ozone hole appears to be on a healing path.

The authors used "fingerprints" of the ozone changes with season and altitude to attribute the ozone's recovery to the continuing decline of atmospheric chlorine originating from chlorofluorocarbons (CFCs). These chemical compounds were once emitted by dry cleaning processes, old refrigerators, and aerosols such as hairspray. In 1987, virtually every country in the world signed on to the Montreal Protocol in a concerted effort to ban the use of CFCs and repair the ozone hole.

Is your makeup killing sharks?

Most animal lovers wouldn’t dream of harming an animal for fashion. Fur? No, thank you. Leather? I don’t think so. Yet they might be unknowingly killing sharks — and highly endangered kinds on top of that — for their beauty routine.

Unbeknownst to most, one little ingredient in products like sunscreens, moisturizing lotions, lip balms, lipsticks and face creams is responsible for the death of over three million sharks annually.

Killer ingredient

“Squalene is a naturally occurring compound found in large quantities in the liver of sharks,” explains the shark protection group Shark Trust. “A sharks’ large oily liver helps to control its position in the water column, however many cosmetics companies use the oil (and an associated compound called squalane) as a base for their moisturizing and skin care creams, lipstick and gloss, as it is non-greasy and softens skin.”

Vermont will be the first US State to Label GMOs

Vermont will soon be the first state in the nation to require labels on genetically modified (GMO) foods. Its GMO-labeling law, the first passed in the nation, goes into effect on July 1. Maine and Connecticut have since passed their own GMO-labeling laws. But they won’t go into effect until neighboring states pass similar legislation.

Crucial peatlands carbon-sink vulnerable to rising sea levels

Rising sea-levels linked to global warming could pose a significant threat to the effectiveness of the world's peatland areas as carbon sinks, a new study has shown.

The pioneering new study, carried out by Geographers at the University of Exeter, examined the impact that salt found in sea water has on how successfully peatland ecosystems accumulate carbon from the atmosphere.

The researchers studied an area of blanket bog - a peat bog that forms in cool regions susceptible to high rainfall - at Kentra Moss, in Northwest Scotland.

Saved by the sun

A new twist on the use of renewable energy is saving children's lives in Africa. The innovation--a solar powered oxygen delivery system--is providing concentrated oxygen in hospital for children suffering from severe pneumonia.

The device created by Dr. Michael Hawkes, an assistant professor in the University of Alberta's Division of Pediatric Infectious Diseases, is the focus of a recently published study in The International Journal of Tuberculosis and Lung Disease and is already in use in two hospitals in Uganda.

"Solar-powered oxygen is using freely available resources--the sun and air--to treat children with pneumonia in the most remote settings," says Hawkes. "It's very gratifying for a pediatrician doing research in a lower-resource setting to fill a clinical gap and save lives. It's what our work is all about."

Floating Solar: A Win-Win for Drought-Stricken Lakes in U.S.

The Colorado River’s two great reservoirs, Lake Mead and Lake Powell, are in retreat. Multi-year droughts and chronic overuse have taken their toll, to be sure, but vast quantities of water are also lost to evaporation. What if the same scorching sun that causes so much of this water loss were harnessed for electric power? 

Installing floating solar photovoltaic arrays, sometimes called “floatovoltaics,” on a portion of these two reservoirs in the southwestern United States could produce clean, renewable energy while shielding significant expandes of water from the hot desert sun. 

Humans artificially drive evolution of new species

Species across the world are rapidly going extinct due to human activities, but humans are also causing rapid evolution and the emergence of new species. A new study published today summarises the causes of manmade speciation, and discusses why newly evolved species cannot simply replace extinct wild species. The study was led by the Center for Macroecology, Evolution and Climate at the University of Copenhagen. 

Pipelines affect health, fitness of salmon, study finds

Pipelines carrying crude oil to ports in British Columbia may spell bad news for salmon, according to a new University of Guelph-led study.

Exposure to an oil sands product - diluted bitumen - impairs the swimming ability and changes the heart structures of young salmon.

The research will be published in the journal Environmental Toxicology and Chemistry, and is available online now.

It's a timely finding, says U of G post-doctoral researcher and lead author Sarah Alderman.

The National Energy Board (NEB) recently approved the controversial Trans Mountain pipeline expansion project; the federal government is expected to make a final decision by December.

Climate Change Is Happening Faster Than African Crops Can Handle It

Crop yields in Africa will nosedive ten years from now unless we can develop varieties that can better deal with climate change. Unfortunately, we’re not breeding those hardier varieties fast enough.

That’s the sobering conclusion of a study published in the journal Nature Climate Change by researchers from the University of Leeds. As temperatures rise, crop yields fall. This is particularly true for staple crops like corn, bananas and beans raised in hot tropical areas.