The concentration of carbon dioxide in the Earth's atmosphere is fast approaching levels not seen for millions of years. At 400 parts per million (p.p.m.), the planet is fast approaching the point of no return for avoiding dangerous climate change.
Scientists are studying whether the stresses of living in urban environments increases the risks of developing mental health disorders. Global urbanization is making the question an urgent one, writes Alison Abbott.
A major mountaintop mining permit is likely to be rejected after an environmental review found "unacceptable" impacts on water quality and wildlife. This would be the first major rebuke to the mining practice, and could foreshadow its end.