articles

Heinrich events, in which large masses of icebergs rapidly broke free from ice sheets during the last ice age, are thought to have influenced global climate by interrupting ocean circulation patterns with a large influx of freshwater. However, new research from the University of Bristol suggests the variations in the height of the ice sheet that happen in these events might also influence global climate. 

In a study published today in PNAS, Dr William Roberts of Bristol’s School of Geographical Sciences and colleagues use computer models to simulate a Heinrich event in Hudson Bay, Canada, adjusting the models to consider freshwater influx only, changing ice sheet height only or both factors together. 

A new study shows that the rise of atmospheric carbon dioxide that contributed to the end of the last ice age more than 10,000 years ago did not occur gradually, but was characterized by three “pulses” in which C02 rose abruptly.

Scientists are not sure what caused these abrupt increases, during which C02 levels rose about 10-15 parts per million – or about 5 percent per episode – over a period of 1-2 centuries. It likely was a combination of factors, they say, including ocean circulation, changing wind patterns, and terrestrial processes.

Researchers from the UK have called into question a theory suggesting that a previously reported risk of leukemia among children born close to overhead power lines could be caused by an alteration to surrounding air pollution. In a study published today, 31 October, in the Journal of Radiological Protection (the official journal of The Society for Radiological Protection), the researchers have found little evidence to support the ‘corona-ion hypothesis’ which has been cited as a possible explanation for the excess of childhood leukemia cases close to high-voltage overhead power lines in the UK prior to the 1980s.

To understand the extent to which human activities are polluting Earth’s atmosphere and oceans, it’s important to distinguish human-made pollutants from compounds that occur naturally. A recent study co-authored by a Brown University professor does just that for ammonium, a compound that is produced by human activities like agriculture, as well as by natural processes that occur in the ocean. The research, based on two years of rainwater samples taken in Bermuda, suggests that ammonium deposited over the open ocean comes almost entirely from natural marine sources, not from anthropogenic sources.

Food waste is a horrendous problem in this country that no one seems to want to talk about. Yet food is the one product type that everyone consumes, and while a surprising number of people don’t have it, those that do are shockingly wasteful. As recently as 2012, close to 50 million people experienced food insecurity, not in Africa or Bangladesh, but right here in the USA. Worldwide, that number is over 1 billion people.