The issue focused on two leaders of the climate campaign, James Hansen and William Armitage, who have been climate scientists for more than 10 years.

Hansen and Armitage have been active in the science of climate change and have also been climate change deniers.

The research was published in the journal Science.

The paper's lead author, senior author and science scientist Emile Reke, said: "It is well known that two things are going to happen to the climate in