RALPH Prothero (Letters, June 21) takes a very cynical view of Joe Cox’s letter about global warming.

The changes in our planet are a warning.

He cannot compare the state of the world nearly a thousand years ago with how it is today.

They were not dumping billions of tons of rubbish into landfill sites or in the oceans.

They were not dumping poisonous chemicals into the atmosphere, under the ground and in our oceans.

They were not drilling into the Earth’s crust to try to find gas, risking the possibility of poisoning the water that gives us life.

The world as we know it can only take so much, then something has to give.

The population of the world is beginning to outstretch food supplies and the resources we rely on like water, gas, oil and electricity.

Where in the future are we going to grow all the food needed when we are busy covering the ground with concrete?

The continents of Asia, America and Russia supply huge amounts of grain and it only takes Mother Nature to cause disasters with the harvest like last year in America with the heat, Russia with the rains, and our own harvest severely damaged with the wet weather.

The Green Party, of which I am not a member, may go over the top with many issues regarding our planet, but at least they try to improve the delicate fabric of our vulnerable world.

Andre Semple, of Maybush, Southampton