From SUSAN M. WELLS
In discussing the precautionary approach in environmental issues, Paul
Johnston and Mark Simmonds (Talking Point, 3 August) emphasised the importance
of ‘an honest appraisal of a given situation’. Recent debate between overtly
‘green’ coral reef scientists and those who are much more cautious illustrates
this well. There is increasing evidence to link coral bleaching to abnormally
high sea temperatures but the available data still do not prove that bleaching
is caused by global warming. Of course it may be, and many reef scientists
are increasingly concerned about what they are seeing on reefs. Some are
already convinced. Equally, the data do not prove that bleaching is not
caused by global warming, as implied by headlines in the journal Science
(19 July).
Obviously such a correlation, or the proven lack of one, would make
better copy for journals like New Scientist and Science. But an ‘honest
appraisal’ of the situation, and one that needs communicating to the public,
is surely that we don’t know yet. Following the argument of Johnston and
Simmonds, this would then call for the precautionary approach – a view that
the majority of reef scientists would hold to, whatever their opinions about
the cause of coral bleaching.
Susan M. Wells Cambridge
