In response to W Keen and P Kelly (The Weekend Sun, January 31, pages 28-29) criticising my letter (The Weekend Sun, January 24, page 27), the following: I was quoting Australian rural fire authorities saying that only three people had been charged with arson, refuting P Kelly's earlier claim that ‘almost 200 [had been] charged with deliberately lighting bush fires', as though explaining the magnitude of these tragic fires. However, meteorologists, scientists and fire authorities are in no doubt that the unprecedented drought and high temperatures are the real culprits.

Re CO2: Although I attend scientific conferences, public addresses and visit scientific websites etc, I have seen no proof that levels were higher 10,000 years ago, only that they fluctuated far below today's high readings - which have been proved beyond doubt to be due to mankind. And yes, our crops all need CO2, but ‘too much of a good thing' would ultimately decimate them - and our descendants - by promoting extreme heat, storms, droughts and fires. And the dinosaurs? With CO2 and temperatures so high, and global sea levels over 60 metres above today's, perhaps they were roaming the green forests then encircling the South Pole, just to cool off? Not my vision of an ideal world!

P Otway, Omokoroa