This year may well go down in history as the one in which climate change finally started to make a dent on the collective conscience, at and industry, government and greater consumer level.

The United Nation's Food and Agriculture Organization has been warning for the last few years, however, that the changes will have a dire effect on agriculture, and be felt most keenly by the poorest nations.

At the same time, concern has been raged for quite some time about depletion of the world's marine resources, mostly as a result of over-fishing.

Now Dr Ian Joint of the UK's Plymouth Marine Laboratory and the Society for General Microbiology is warning that carbon dioxide in the atmosphere could affect microbial life in the sea. This will have an impact on microscopic plants eaten by fish - and in turn, the fish themselves - a major source of protein for man.

Dr Joint is presently involved in sequencing the DNA of bacteria that reside in the ocean, with a view to seeing how an increase in carbon dioxide will affect them.

"So far from one experiment we have sequenced 300 million bases of DNA, about one tenth the size of the human genome. We are analyzing this 'ocean genome' to see if changes might affect the productivity of the sea," he said following an event at the Science Media Centre in London last week, Dr Joint. "We want to find out if human activities will have a major impact on microbial life in the seas and if this is likely to be a problem for mankind in the future."

In addition being a food source for fish, bacteria also play an important role in making the earth suitable for human habitation.

They have a role to play in controling the cycling of oxygen, carbon, nitrogen and sulphur in the sea, and are responsible for generating half of the oxygen produced globally every year, Dr Joint said.

Joint noted that the carbon dioxide produced by human activity is "turning the oceans into weak acids".

"Bacteria still control the world" he said. "They ensure that the planet is fertile and that toxic materials do not accumulate."

Since, this century, the seas will be more acidic than they have been for 20 million years, these bacteria may well have their work cut out in maintaining the status quo.