Climate scientists in the US say police inaction has left them defenceless by in the face of a torrent of death threats and hate mail, leaving them fearing for their lives and one to contemplate arming himself with a handgun.

The scientists say the threats have increased since the furore over leaked emails from the University of East Anglia began last November, and a sample of the hate mail sent in recent months and seen by the Guardian reveals the scale and vitriolic tone of the abuse.

The scientists revealed they have been told to "go gargle razor blades" and have been described as "Nazi climate murderers".