Guardian: The news that concentrations of carbon dioxide in our atmosphere reached a level of 400 parts per million last week might not appear to have immediate significance. The level is only a couple of units higher than last year, after all. Yet the development has undoubted importance.
With the realisation that carbon dioxide levels have achieved that symbolic 400ppm figure, it is now clear that two decades of warnings from scientists have fallen on deaf ears and that our leaders have failed completely...