Global warming could produce hundreds of extra cases of food poisoning in Northern Ireland, an environmental health chief claimed today.

Bacteria may prosper because of hotter summers, Gary McFarlane added. An ageing population will be more susceptible to diseases.

Summer temperatures in Belfast could hit 32 degrees by 2080 if we keep emitting so many greenhouse gases, the Met Office has warned.

Mr McFarlane gave evidence to Stormont's Environment Committee.

"This is the most significant health issue that the world has ever faced and in Northern Ireland we need to play our part as part of the society that we all live in... and we are not doing it at the minute," he said.

Extra cost to the economy across the UK will be around £1.5 billion, Mr McFarlane, director of the Chartered Institute of Environmental Health, added.

He said on a UK-wide basis there could be 10,000 extra cases of food poisoning a year if temperatures increase as anticipated between now and 2050 in the UK. A breakdown of that per head of population would indicate over 200 cases in Northern Ireland.

There are implications for pest control, obesity, mortality rates and the potential for new and infectious diseases, Mr McFarlane added.

He said: "If we do nothing about climate change it will get to a point where the investment required in our health system just to tread water will become such that there will be no money left for anything else.

"Prevent it happening or try and deal with it when it is happening."

According to the Food Standards Agency, in the longer term climate change could have an impact.

"Department of Health analysis indicates a 1°C rise would increase all food-borne disease by 5% and Salmonella in the UK by 12%. And an ageing population will be more susceptible to food-borne illness," it added.

DUP committee member Alistair Ross expressed scepticism about any link between obesity and climate change and accused the witness of sensationalism.

SDLP committee member Tommy Gallagher said: "It is certainly a very compelling reason why we should be doing something about global warming and the way we do that is by setting local targets and the Executive here should be looking at this now."

Ulster Farmers' Union (UFU) president Graham Furey said: "Climate change presents significant threats to farmers, for example weather extremes, but also opportunities, for example we may be able to grow new crop types.

"It is important that Northern Ireland is ready for potential changes by carrying out the necessary research work and technology transfer.

"This may necessitate looking again at GM (genetically modified crops) policies."