WILL AN ANCIENT CLIMATE-CHANGE REPEAT?

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ScienceDaily report on an international study of the abrupt, runaway climate-change that took place 635 million years ago, due to a massive release of methane, raises the possibility that we may trigger a similar event, and cause a global temperature rise of tens of degrees.

REACTIVE NITROGEN AS SERIOUS AS CO2?

ScienceDaily reports the growing alarm among scientists at the increase in the environment of reactive nitrogen, which may be as serious a problem for the human race as the growing concentration of carbon-dioxide in the atmosphere.

In its inert form, nitrogen is harmless and abundant, making up 78 percent of the Earth's atmosphere. But in the past century, with the mass production of nitrogen-based fertilisers and the large-scale burning of fossil fuels, massive amounts of reactive nitrogen compounds, such as ammonia, have entered the environment.

A nitrogen atom that starts out as part of a smog-forming compound may be deposited in lakes and forests as nitric acid, which can kill fish and insects. Carried out to the coast, the same nitrogen atom may contribute to red tides and dead zones. Finally, the nitrogen will be put back into the atmosphere as part of the greenhouse gas nitrous oxide, which destroys atmospheric ozone.

CARBON-DIOXIDE HIGHEST IN 800,000 YEARS

ScienceDaily reports that the study of Antarctic ice-cores has established that the present concentration of carbon-dioxide is higher than it has been at any time during the past 800,000 years. It is now a bit more than 380 parts per million, compared to a range of about 200-300 parts per million during that time. The current concentration of methane is 1,800 parts per billion, compared to a range of about 400-700 parts per billion during that time.

OVER A QUARTER OF WORLD'S WILDLIFE GONE

Between a quarter and a third of the world's wildlife has been lost since 1970, according to data compiled by the Zoological Society of London, reports the BBC.

The Society says populations of land-based species fell by 25%, marine ones by 28% and freshwater ones by 29%, and that humans are wiping out about 1% of all other species every year--that one of the "great extinction episodes" in the Earth's history is under way.

GLOBAL OVERHEATING IS CHANGING NATURE

Major changes in the Earth's natural systems are being driven by global warming, according to a vast analysis, says a BBC report, citing research published in the journal Nature.