SIR - Rising global Carbon Dioxide levels lag rising global temperatures by some 800 years, this has been proved.

Councillor Brown (Let's be sensible over Earth's climate crisis, Craven Herald letters, August 22) states that scientists have measured the level of Carbon dioxide and found that it has now reached 417 parts per million, a level which hasn't been seen since the time of the dinosaurs. This is probably true but mankind is only responsible for 4 percent of that.

With a World population of 7.7 billion people and a Craven district population of some 54 thousand people. A little bit of arithmetic shows that the people of Craven contribute just under three parts per billion of carbon dioxide to the atmosphere. So, even if carbon dioxide were responsible for a warming Earth, making Craven "carbon neutral" would have no perceivable effect.

What is being omitted here is that the level of carbon dioxide was five times greater when the dinosaurs roamed a flourishing Earth and that was a long time before "polluting" mankind came along.

Old Mother Earth didn't do too badly out of that, did she?

One thing that I have never understood about the Green Party is why they are so anti carbon dioxide, the gas that is essential to photosynthesis, which is what makes the Earth green in the first place.

John McKay

Horton in Ribblesdale.