Australian Broadcasting Corporation: DAVID MARK: The level of carbon dioxide in the atmosphere grew more last year than at any time in modern history.
The current level of CO2 is 402 parts per million. Maintaining levels below 450 parts per million is considered necessary to limit global warming to two degrees.
The warming effect of the El Nino weather pattern was a big factor last year, but the new record is still seen as a big wake-up call as global warming races ahead.
Australian researchers are warning that the world is…