I AM sorry to have given the impression to Mr Weeden, (letters June 4), that I have been reading too much science fiction.

I would like to assure Mr W that my information regarding the Atlantic Meridional Overturning Circulation (Gulf Stream) came directly from a marine biogeochemist with distinguished credentials in this field of work.

If Mr Weeden would like further details of where some of this large body of published scientific research can be accessed I would be happy to pass it on to him.

Celia Carter, Fremantle Road, High Wycombe.