Guardian: Europe has become less foggy over the past three decades, according to scientists who have examined weather records across the continent. Fog, mist and haze have become less frequent and have contributed, they calculate, to between 10% and 20% of the warming trend during that period. The change is down to reduced air pollution, the scientists think. Robert Vautard at the Atomic Energy Commission in Gif sur Yvette, France, and colleagues, looked at the number of “low-visibility” …