Carbon dioxide passes symbolic mark - Noaa atmospheric lab - The measurements are made at a station on the Mauna Loa volcano The level of carbon dioxide in the atmosphere has risen above 400 parts per million for the first time in human history, US researchers say. The "Keeling Lab" in Hawaii has the longest continuous measurement of the greenhouse gas, which is a key driver of climate change. Thursday's measurement, made atop the Mauna Loa volcano, registered 400.03. The last time CO2 was regularly above 400ppm was about 3-5 million years ago - before modern humans existed. The climate back then was also considerably warmer than it is today, according to scientists. The usual trend seen at the volcano is for the CO2 concentration to rise in winter months and then to fall back as the northern hemisphere growing season kicks in and pulls some of the gas out of the atmosphere. This means the number can be expected to decline by a few ppm in the coming weeks. But the long-term trend is upwards. When the late Charles Keeling began recording CO2 concentrations at the volcano in 1958, they were around 315 ppm (parts per million by volume - that is 315 molecules of CO2 for every one million molecules in the air). Every year since then, the curve has squiggled resolutely higher.

Oil sands' toxins accumulate in freshwater ecosystems

 

 
Studies have shown that oil sands operations lead to pollutants being released into water systems
 

Toxic pollutants released by oil

sands mining operations are accumulating in freshwater ecosystems, research by

Canadian scientists suggests.

A study of sediment in nearby lakes showed the level of pollutants, known as

PAHs, had risen since the 1960s when oil sands development began.

However, the researchers added that PAH concentrations were still lower than

those found in urban lakes.

The findings appear in the Proceedings of the

National Academy of Sciences

.

PAH refers to polycyclic aromatic hydrocarbons - a group of chemicals that

have been shown to affect aquatic organisms and birds. PAHs have also been

described as being responsible for damaging food crops.

The chemicals occur naturally in coal, crude oil, and petroleum; they are

also present in products made from fossil fuels, such as creosote and asphalt.

PAHs also can be released into the air during the burning of fossil fuels and

organic matter - the less efficient the burning process, the more PAHs are given

off. Forest fires and volcanoes produce PAHs naturally.

Over-consumption in rich countries

and rapid population growth in the poorest both need to be tackled to put

society on a sustainable path, a report says.

An expert group convened by the Royal Society spent nearly two years reading evidence and writing their

report.

Firm recommendations include giving all women access to family planning,

moving beyond GDP as the yardstick of economic health and reducing food

waste.

The report will feed into preparations for the Rio+20 summit in June.

"This is an absolutely critical period for people and the planet, with

profound changes for human health and wellbeing and the natural environment,"

said Sir John Sulston, the report's chairman.

"Where we go is down to human volition - it's not pre-ordained, it's not the

act of anything outside humanity, it's in our hands."