An undated file photo shows wind power generators. Development of alternative energy should create more than 20 million jobs around the world in coming decades as governments adopt policies to reduce greenhouse gas emissions, according to a UN report released Wednesday.

Development of alternative energy should create more than 20 million jobs around the world in coming decades as governments adopt policies to reduce greenhouse gas emissions, according to a UN report released Wednesday.

Some 2.3 million people already work in green energy jobs with half of them in biofuels, said the report "Green Jobs: Towards Decent Work in a Sustainable, Low-Carbon World," commissioned and funded by the UN's Environment Program.

Creation of the jobs will depend on countries implementing and broadening policies, including capping emissions of greenhouse gases and shifting of subsidies from old energy forms to new ones, in the effort to slow global warming, it said.

The report was written before the US credit crisis reshaped Wall Street and reverberated around the world, which could slow many sectors, including alternative energy.

It said some 12 million new jobs could be created by 2030 in biofuels-related agriculture and industry.

Biofuel critics say current US ethanol, which is mostly made from corn, does little to reduce greenhouse gas emissions. But companies are racing to make cleaner, next-generation ethanol from sources including crop waste and rapidly growing non-food crops like and poplar trees.

The report said many jobs in the biofuels industry are unfair to workers. "Much of the employment on sugarcane and palm oil plantations in countries like Brazil, Colombia, Malaysia and Indonesia is marked by poor pay and dangerous working conditions," it said.

"There is also concern that large-scale biofuels production might drive large numbers of people off their land in future years," it said.

Manufacturing, installing, and maintaining solar panels should add 6.3 million jobs by 2030 while wind power should add more than 2 million jobs. Even more jobs could be created in the building, recycling, clean vehicle manufacturing sectors, the report said.