The obvious climatic and fiscal stupidity of such investments is staggering, say environmentalists.

"What are they (the banks) thinking?" asked Leslie Lowe, energy and environment programme director at the Interfaith Centre on Corporate Responsibility.

Carbon regulations are coming, and profiting from the destruction of nature and communities is immoral in any case, Lowe told IPS at a press conference.

"It is folly to build new coal-fired plants," she said.

And yet that is just what Bank of America and Citi (formerly Citigroup) are doing, according to the new report "Banks, Climate Change & the New Coal Rush" by the Rainforest Action Network (RAN).

Electricity generation from coal is the biggest source of carbon dioxide (CO2) emissions in the world -- larger than deforestation or the transportation sector, says Rebecca Tarbotton, director of RAN's Global Finance Campaign

The 150 proposed new plants would add 600 million to 1.1 billion tonnes of carbon annually into the atmosphere, Tarbotton said in an interview. Total global emissions of carbon are currently about 8 billion tonnes.

"There is no hope of averting climate catastrophe if a significant number of those plants are built," said Bill McKibben, author and founder of Step It Up, the largest demonstration against global warming in history.

"Climate change is already happening much faster than anyone expected," McKibben told IPS.

In the past two weeks, reports that the Arctic ice cap shrank dramatically this summer have left scientists shocked at the speed and extent of the melting. The Arctic Ocean may well go from white to blue in less than a decade, some believe. The ramifications of an ice-free Arctic on the world's weather system and the local ecology have yet to be determined.

Coal currently supplies approximately half of the U.S.'s electricity and produces 80 percent of the sector's CO2 emissions. Building new coal-fired plants -- which have projected lifespans of 50 years -- would undo virtually any and all domestic efforts to reduce carbon emissions, notes McKibben.

RAN and the coalition of environmental and faith-based groups, as well as Al Gore, Senators John Edwards and John Kerry, and Senate Majority Leader Harry Reid, are calling for a moratorium on all new coal-fired plants.

"I can't understand why there aren't rings of young people blocking bulldozers and preventing them from constructing coal-fired power plants," former U.S. vice president and prominent global warming campaigner Al Gore was reported as saying by the New York Times last August.

"It's (also) financially ludicrous to be backing a 19th century technology rather than 21st century technologies," McKibben said.

Instead of investing the estimated 140 billion dollars in coal, financial institutions should be investing in clean energy options like solar, wind and energy efficiency, says RAN's Tarbotton.

"Investing that amount in energy efficiency improvements could reduce U.S. electricity demands by 19 percent by 2025, eliminating the need for new coal power plants," she said.

It should not be forgotten that digging coal out of the ground involves mountaintop removal, enormous strip mines and millions of tonnes of toxic waste that have devastated many parts of the country, she says.

"It's a war zone in southern West Virginia, three and half million pounds of explosives go off every day," said Julia "Judy" Bonds, founder of Coal River Mountain Watch.

"They are poisoning our water and our air. I want Citi and Bank of America to realise that when they fund coal companies, they are ruining lives and killing communities," Bonds said.

Citi is a leading financier of fossil fuel energy and the world's top financier of coal. According to Forbes, Citi's assets of 2.2 trillion dollars make it not just the world's largest bank, but the biggest company, the report found. Citi is also the top source of investment for the coal sector, providing more than 4 billion dollars in financing to Peabody Energy, the world's largest coal mining company.

Citi has financed billions of dollars to coal mining companies that practice mountaintop removal (MTR), including Massey Energy, Arch Coal, Alpha Natural Resources and others. These companies are responsible for the loss of more than a million acres of Appalachian forests and mountains, the report notes.

In 2006, Citi underwrote more than 38 billion dollars for the energy industry while financing just one transaction for alternative energy -- 200 times more money for "dirty energy" -- despite claims of being the United States's "greenest" bank, said Tarbotton.

There are plenty of alternative energy projects that need financing, and the coalition's hope is that the banks would no longer fund coal and pull their existing financing.

As for the much hyped "clean coal" technology, environmentalists say there isn't any practical way to capture and store carbon emissions currently, and even if the problem can be solved, solutions are one to two decades in the future.

"There's nothing clean about coal mining," says Bonds. "It's a real insult to the people who have to live in coal mining communities."

"The only clean coal is the coal that's left in the ground," concludes Tarbotton.

Neither Citi nor Bank of America could be reached for comment.