Britain has emerged as the world leader in carbon emissions trading spending billions of pounds to offset CO2 atmospheric pollution.

Estimated value of carbon trading in the UK will be worth around US$800 billion by 2020.

When, as expected, Japan and the US follow Europe into a "cap and trade" mechanism in the next two years a vast new international market in carbon trading will open up.

However, a report recently published raises concerns that many schemes that sell carbon credits to offset pollution are delivering 30% less than promised. The scale of problems found with existing credit schemes - many operated under United Nations projects - will fuel criticism that the world cannot rely totally on carbon markets to tackle climate change.

According to Ian Johnson, chairman of the ratings company IDEAcarbon, while carbon projects are "delivery well" the performance of the average carbon credit projects was around a third less than forecast.

Johnson asserts that the past five years has been a period for learning that was essential for bringing investments into line with the climate science of global warming.

IDEAcarbon's analysis of 25 carbon-offset projects, offered under two UN schemes that of the 20 biggest credit providers that account for 75% of the market, all delivered their promised carbon savings.

But hundreds of smaller projects issuing credits - that included biomass in Brazil, wind energy and efficiency in India, and landfill gas in South Africa - were delivering on average around 70% of what was promised.

www.DailyPlanetMedia.com has learned that an estimated 3,000 carbon-

credit projects are currently in operation worldwide generating around US$14 billion in trade.

Best performers were energy-efficiency and renewable-energy schemes, while the worst were burning landfill gas and coalmine methane.