Sydney Morning Herald: TWO KEY greenhouse gases in the Earth’s atmosphere rose sharply last year, and carbon dioxide levels this year are showing an alarming increase, the US Government has reported. In its annual index of greenhouse gas emissions, the US National Oceanic and Atmospheric Administration found atmospheric carbon dioxide, the primary driver of global climate change, rose 0.6 per cent, or 19 billion tonnes, last year. The amount of methane rose 0.5 per cent, or 27 million tonnes, after …