As the world contemplates a greener future, the biogas industry is leading the way. With 10% of Britain's energy expected to come from renewable biogas from anaerobic digestion by 2020, we take a look at the industry and find out what it's all about.

Copenhagen might have ended in disaster, but all hope for the future is not yet lost.

That's because a low-carbon, global economy may still rear its beautifully green head - as long as renewable energies like biogas are given the funding and importance they so deserve in the near future.

Solar and wind power have long been touted as the green energies that will save us from economic and ecological collapse. But not enough has been said about biogas - a renewable form of energy produced from biodegradable waste such as food, sewage and animal manure through a process called anaerobic digestion.

Anaerobic digestion uses micro-organisms (like bacteria) to break down agricultural and household waste to produce methane gas and carbon dioxide.

Those gases are then cleaned and converted into electricity or injected into the gas mains.

The end result, biogas, is already widely produced and used in gas grids across Europe. In fact, in Germany, France and Austria, biogas stands as a viable replacement for natural gas and vehicle fuel.

The real and potential applications of biogas are so great that the National Grid - which owns both the gas and electricity transmission systems in Great Britain - recently proclaimed it a viable solution in heating homes here in the UK as well.

"Biogas has benefits on so many fronts," explains Janine Freeman, head of the National Grid's sustainable gas division.

"It provides a solution for what to do with our waste with the decline in landfill capacity, and it would help the UK with a secure supply of gas as North Sea sources run down."

A biogas future Renewable gas production - in the form of landfill and sewage gas - currently represents a large proportion of the UK's current renewable energy portfolio.

As the UK is expected to cut its emissions by 80% by 2050, a not-too-easy feat given our current energy consumption rates, the race is on to find the world's greenest (and most renewable) energy.

That's why the UK's Anaerobic Digestion and Biogas Association (ADBA) has recently called on the Government to recognise the potential biogas could have on Britain's future gas, electricity and heat supply.

The ADBA predicts that biogas could supply two thirds of Britain's renewable targets by 2020, employ as many as 40,000 people, and produce up to 20% of Britain's domestic gas supply.

It says that farmers and local authorities could build as many as 1,000 anaerobic digestion plants in the next five years at a cost of £5 billion (mostly funded by the private sector), with the aim to generate gas worth £1.7 billion per year.

A viable alternative With all eyes looking towards windmills as the emblem of the future, perhaps some of them should be taking a look at our heaving landfills instead, which is waste just waiting to be converted into energy.

One of the major benefits to biogas is that it can be delivered using existing gas infrastructure. This means that no new pipelines have to be dug, no new pipes fitted.

And considering that the UK already has an extensive gas mains coverage, biogas is a technology that could benefit quite a lot of people in very little time.

Investing in biogas technology has another benefit: It solves the UK's landfill problem by diverting landfill waste into renewable energy.

The UK boasts some 4,000 landfill sites, according to Waste Online, which are estimated to contribute 1.5 million tonnes of methane into the atmosphere every year.

Methane is a major greenhouse gas and contributes to global warming.

As the UK's landfills are nearly at full capacity, alternative forms of waste disposal, such as incineration, have been suggested.

But because anaerobic digestion has far fewer emissions than incineration, it is one of the most viable waste disposal alternatives to landfill.

Not only does it treat waste and convert it into energy, it also creates high-quality fertiliser as a by-product, which could help reduce imports of fertiliser into the UK.

Green electricity company Ecotricity has already cottoned onto the idea and plans to build 'green gas mills' to supply UK customers with a 'green gas' tariff based on biogas.

Britain discards some 18 million tonnes of food waste alone per year, which Ecotricity said could generate enough biogas to heat 700,000 homes. The company hopes to eventually source 50% of its gas from biogas, and is already encouraging customers to register for its green gas tariff.

And it wouldn't cost an arm and a leg, either. According to a National Grid report, the cost of implementing biogas here in the UK is comparable to other large-scale renewables, such as wind power.

The next step At present there are only a small number of anaerobic digestion plants in the UK. One is a Scottish Water Waste Services plant in North Lanarkshire, where 30,000 tonnes of wet waste - a combination of kitchen, commercial food, fish and segregated kerbside slop - are cleaned and converted into 8,000MW of energy a year. The resulting compost is a bonus.

Rumours have also been circulated that local councils in London, Glasgow and Manchester are considering emulating a German model and implementing the UK's first biogas arrangement - which would be the world's first urban biogas network.

However, despite the UK's targets to source 15% of its energy from renewable sources by 2020, the chairman of ADBA, Lord Redesdale, has voiced concern that not enough attention has been paid to biogas.

"At a time when the cost and security of our gas supply is in jeopardy, when there is so much public support for renewable technologies, and when we do not look like we are going to hit our renewable and recycling targets, it is surprising that anaerobic digestion is not one of our top priorities," he says.

"Anaerobic digestion will convert waste into power, with the added benefit that the residue is a fertiliser that can be put back on the land."

There is still time, however, to learn from our mistakes. Copenhagen may have failed to set binding targets, but there was one lesson to be learned from the UN Climate Change Conference hosts in December.

Denmark treats some 1.1 million tonnes of waste by anaerobic digestion every year in biogas plants dotted around the country. This alone - not to mention the sight of such plants along the Copenhagen skyline - proves that the seemingly impossible is, in fact, completely possible.