TONY Sykes (Letters, October 10) claims not one person in the UK has been hospitalised due to passive smoking.

The British Medical Journal reported in 2005, before the ban on smoking in public indoors, that 11,000 people a year were dying in the UK due to passive smoking.

Only 600 of those were due to smoking in the workplace, suggesting that many died due to smoky pubs and members of their family smoking in their own home. The smoking ban will have changed the first but not the second.

The World Health Organisation reported last year that 600,000 people a year die due to passive smoking, one-third of them children.

Mr Sykes's claim about "worldwide scientific data that man makes no contribution to global warming" needs to specify what studies he is referring to and who carried them out. The scientists on the International Panel on Climate Change reported in 2007 that average annual global temperatures are rising at an unprecedented rate and that there is a more than 90% probability that most of this change is due to human activity. An independent review of 928 scientific research papers found 75% of climate scientists agree with the IPCC's assessment and none strongly disagrees with it.

It's certainly true that some parts of the earth are cooling while others are warming, but that is one of the possibilities predicted by climate scientists – for instance that global warming could lead to less difference in temperature between the poles and the tropics, weakening or ending the Gulf Stream (a convection current) and resulting in the UK's climate becoming more similar to Alaska's.

These are two cases in which politicians have acted on the basis of scientific research, though in the second case not nearly enough yet.

Duncan McFarlane,

Beanshields,

Braidwood, Carluke.