In response to letters by Charles Bulman and others (July 11), to put it simply take the earth and its resources as a large cake. The more people wanting a slice the smaller the slice until we get down to the smallest crumb!

An ever-growing population is the biggest driver of climate change. There are not enough crumbs to go around.

Advances in medicine leading to a longer lifespan for most, including those in what are known as third world countries, is a factor which we cannot change. Neither can we change the desire for those in such countries to want what we in the western world have had for so long. The génie cannot be put back in the bottle!

While many see the solution in reducing our carbon footprint, could we ever realistically reach zero carbon emissions? I doubt this very much. We as humans and, of course, all other animals breathe oxygen in and carbon dioxide out both at rest and when active.

Plants, while making use of carbon dioxide, also give this off mainly at night but the balance of use is believed to outweigh the amount of carbon dioxide plants give off.

Maybe nature will rebalance itself but we as humans do need to be less wasteful.

Mrs Symington