DEAR SIR: I refer to my comment in a recent opinion piece concerning Professor Lindzen’s links with the tobacco industry. My comment was based on the following statement regarding Professor Lindzen in Professor James Hansen’s book Storms of My Grandchildren.

“He had been a witness for tobacco companies decades earlier, questioning the reliability of statistical connections between smoking and health problems.” (Hansen, 2011, P15.) Professor Hansen is a former head of the NASA Goddard Institute for Space Studies in New York City and more recently has directed the Program on Climate Science, Awareness and Solutions at Columbia University’s Earth Institute. Notwithstanding this, I am content to accept Professor Lindzen’s contention that there is no foundation to the statement concerned and I unreservedly withdraw it and apologise for any inconvenience caused.