Climate scientists face harassment, threats and fears of 'McCarthyist attacks'

Researchers will have to deal with attacks from a range of powerful foes in the coming years - and for many, it has already started

A little less than seven years ago, the climate scientist Michael Mann ambled into his office at Penn State University with a wedge of mail tucked under his arm. As he tore into one of the envelopes, which was hand-addressed to him, white powder tumbled from the folds of the letter. Mann recoiled from the grainy plume and rushed to the bathroom to scrub his hands.

Fortunately for Mann, the FBI confirmed the powder was cornstarch rather than anthrax. It was perhaps the nadir of the vituperation hurled at Mann by often anonymous critics who accuse him and others of fabricating or exaggerating the dangers of climate change.