Pub patio heaters for smokers will produce 'as much pollution as a small city'

Next month's smoking ban has triggered huge demand for the gas-fired heaters from pubs, restaurants and clubs creating legal outdoor smoking areas.

But according to experts, a single heater releases more carbon dioxide into the atmosphere each year than the average fuel-hungry "Chelsea tractor" - a large 4x4 car.

They estimate the additional patio heaters bought by pubs this year could produce up to 320,000 additional tons of carbon dioxide.

This equates to a "substantial chunk" of the annual reduction in greenhouse gases needed to meet Britain's Kyoto targets and close to the carbon emissions from every home in a city the size of Bath.

Although some DIY stores have banned patio heaters, tens of thousands of pubs have added them to gardens and outdoor areas to keep smokers happy.

"It's pretty sad that keeping warm while you have a cigarette is more important than tackling climate change, especially in a country familiar with simpler remedies to chilly evenings such as the woolly jumper," said Ben Tuxworth, of the environmental charity Forum for the Future.

The findings come from British Gas, which studied the impact of pub patio heaters as part of its energy saving campaign. It found half of all pubs in Scotland bought at least one patio heater after the smoking ban in March 2006. Many bought several.

With a single heater releasing almost four tons of greenhouse gases a year, the patio heaters installed in Scotland produced up to 10,000 tons of carbon dioxide in their first year, the company said.

British Gas estimates a minimum of 40,000 heaters will be bought for the July 1 deadline by English pubs.

That would produce around 160,000 additional tons of carbon.

If pubs buy two, the emissions would rise to 320,000 - the equivalent to the annual domestic carbon output of a small city. The estimates are based on Government findings that a typical commercial patio heater is used for around five hours a day, 237 days a year.

Jon Kimber, the company's spokesman on energy efficiency, said many homes were working hard to improve their energy efficiency.

"There has been a real step change in people's concerns about reducing their impact on the environment and it's worrying to see these efforts cancelled out by a sudden boom in patio heater sales," he said.

Earlier this year the garden chain Wyevale stopped selling patio heaters after pressure from environmental campaigners. According to Friends of the Earth, the energy used by a heater in one hour is the equivalent of boiling a kettle enough times to make 400 cups of tea.

Friends of the Earth director Tony Juniper said: "Patio heaters waste energy and inflict unnecessary damage on the environment.

"Ministers must do more to get their climate strategy back on track. It's time to ban the sale of these metal monstrosities."

The smoking ban in indoor public spaces begins on July 1 in England. Wales and Northern Ireland introduced their bans earlier this year.